ALH TDI engine transplant into '84 Vanagon

Knock wood, I am still running a stock 1.6 NA diesel flywheel and clutch setup. I must drive it really easy. Even with the bigger nozzles, no indication that the clutch is wearing or starting to slip. Must be lucky.

For the hard start hot. Even though the old battery seemed to crank the engine fine, the new battery seems to crank it faster. No problems with a hard start hot last night. I believe I need to replace the thermostat now. The engine seems to take forever now to come up to temp and barely gets to 180F where it used to get to 188/190F. Guess it is always something. markw

Taking a break.....

Well, the clutch disc come at 11:30 today. After two and half hours, I could not get the tranny to slide up to the enigine.

I pulled the tranny back out. Apparenty it was off angle enough that the splines got burred on the disc as I rotated the engine back and forth trying to get it to fall together. After de-burring the splines, I had the tranny up and in position to fall in place in less than 45 minutes. Bingo!

The improvement in the motor mount bracket seems to be okay.

.....back to the garage to finish up all those loose ends. Hopefully I can leave here early in the morning to make it to Dan's GTG by or before noon tomorrow! http://forums.tdiclub.com/showthread.php?t=369479

Good luck!!!

Too tired to even think about it!

Ski in NC said:

Good luck!!!

Click to expand...

Well, I sure needed it..... the luck!

Unfortunately, as in bad luck, ..... I hit the starter at about 11:00 pm, nothing but engagement! It did not turn the engine 1/2 degree.

I cannot turn the engine in either direction! Damn! ...as in solidly locked! I have a special cut two by four (2X4) for holding the clutch pedal to the floor ... still no turn. I am 100% positive the tranny is in neutral. I actually loosened the starter bolts and let it drop back.......

So, I'm thinking something in all the pieces parts of the Flywheel/clutch disc/pressure plate don't match...... It's probably in direct contact with the side of the bell housing. However, when I compared the depth of the 228mm pressure plate with the 215mm, I could not see any difference. (yeah, I turned the clutch disc the right direction) I did not like the looks of the pressure plate when I finished bolting it to the flywheel. The fingers looked almost flat! But, the smaller pressure plate on it's flywheel looked about the same .....scratching my head!

Although I did do a TB job and never started the engine, it was done prior to removing the tranny and old flywheel. Everything was perfectly in time. And, I did rotate the engine two times.....all lined up!

The issue is with the new flywheel/clutch!

So, tomorrow, I will sort it out!

AndyBees said:

Well, I sure needed it..... the luck!

Unfortunately, as in bad luck, ..... I hit the starter at about 11:00 pm, nothing but engagement! It did not turn the engine 1/2 degree.

I cannot turn the engine in either direction! Damn! ...as in solidly locked! I have a special cut two by four (2/4) for holding the clutch pedal to the floor ... still no turn. I am 100% positive the tranny is in neutral. I actually loosened the starter bolts and let it drop back.......

So, I'm thinking something in all the pieces parts of the Flywheel/clutch disc/pressure plate don't match...... It's probably in direct contact with the side of the bell housing. However, when I compared the depth of the 228mm pressure plate with the 215mm, I could not see any difference. (yeah, I turned the clutch disc the right direction) I did not like the looks of the pressure plate when I finished bolting it to the flywheel. The fingers looked almost flat! But, the smaller pressure plate on it's flywheel looked about the same .....scratching my head!

Although I did do a TB job and never statered the engine, it was done prior to removing the tranny and old flywheel. Everything was perfectly in time. And, I did rotate the engine two times.....all lined up!

The issue is with the new flywheel/clutch!

So, tomorrow, I will sort it out!

Click to expand...

thats a bummer man .... hasenwerk mentioned in this post about potential interference issues

http://forums.tdiclub.com/showpost.php?p=3998328&postcount=851

Well, being so worn down physically and mentally, I just layed around the house today.

So, I'm going out to the garage around 3:00 to open this thing up and see what happened.

There are two "V" shaped tabs on the pressure plate that stuck out parrallel with the plane of the flywheel/clutch plate facing the bellhousing. Also, on the bottom of the bellhousing back toward the tranny just below the release bearing are two (maybe three) "small ribs" that may have interferred. I looked it over and come to the conclusion there would not be a problem .........

I'm just curious as to whether or not those two tabs on the pressure plate can be knocked down without affecting performance/balance? I'd think balance would be more of an issue.

Yes, I do remember someone mentioning clearance issues that only required minor material removal. I forgot about it being David Hasenwerk.

G60 Clutch issues contacting bellhousing

Okay, the problem is that the pressure plate did make contact with the upper part of the bellhousing in three places. I'm not sure if grinding those areas down will solve the problem.

I have an extra bellhousing. So, I suppose grinding those same areas off and then bolt it up to the engine for observation will be the best way to approach the problem. I can hand crank the engine over to see if any other areas make contact and go from there.

Here are a few pics of clutch related stuff as well as the problem.

Below, is a comparison of the 228mm clutch to the 215mm..


Below, is another comparison view of the 228mm vs the 215mm clutch disc


Below, is another comparison view ofthe 228mm vs the 215mm clutch (yeah, Sachs makes them in Mexico now)


Below, in this pic is the G60 flywheel bolted to the ALH engine.


Below, is a pic of the clutch disc on the flywheel with a pilot shaft holding it in place.


Below, is a pic of the fingers of the 228mm pressure plate (obviously, not bolted down)


Below, is a pic of the fingers of the 228mm presure plate installed and bolted down.




Below, in this pic, inside of the bellhousing, you can see two "spots" the pressure plate was making contact... one spot is on the bottom of the TDC pointer and the other is to the right there on a casting mark.


Below, in this pci, left inside of the diesel vanagon bellhousing (starter hole top right), you can see another "spot" there to the left where the pressure plate was making contact with a casting mark


Below, in this pic you are looking at the bottom inside of the diesel vanagon bellhousing. Those three ribs was what I suspected my be making contact with the pressure plate...... apparently not!


Well, I'm going to let it sit until Monday!

Hot starts and/or warm day cold starts

rsxsr said:

Andy, after search Hard Start Hot here, came across quite a few threads. Thank you to those that pointed me in that direction. Not sure if your ECU falls into the problem category, but seems there is a software glitch where above a certain engine temp, and below 250 rpm, no fuel is delivered to the injectors. Changing the adaption to Automatic applies a different starting map. It can become more pronounced as starters wear, batteries get weak and someone traced it to their dual mass flywheel setup.

To test if the problem is ECU related, when it won't start, disconnect the coolant temp sensor and try again. If it starts immediately, you are on the right track. There is a fix called the "Hamman Mod", not to be confused with the "Hammer Mod". It involves adding a resistor into the coolant temp circuit and activating with a push button or adding a relay tied to the starter circuit. This tricks the ECU into thinking it is colder than it is and puts the ECU into a different starting section of the map. Here is a link to a long thread. If nothing else it will make you feel better about not being the only one with this problem. http://forums.tdiclub.com/showthread.php?t=134622&highlight=Hamman

The real fix is to send the ECU out and have it reprogramed. Here is something interesting though. Today, I went to take the Van to work and the battery would not crank the engine. It was fine yesterday evening. So, maybe in my case, the battery was just on it's way out. mark

Click to expand...

Mark, these comments are to your post and my post just after it (#927).

It's amazing at the number of SWAGes that are in the first part of that Thread link........ "timing", "starter", "battery", "GPs" and so on!

Well, looking at the Vanagon electrical schematics, it would be an easy task to add a simple relay to the X circuit coming off the ignition switch (X circuit wiring is always black and yellow). In the ON position, the relay would be activated making a complete circuit between the Coolanbt Temperature Sensor (CTS) and the ECU. Once the ignition switch is turned to the "Start" position the X circuit is turned OFF. Thus, the ETC circuit that goes through the relay would be broken (turned OFF)........... the engine temp would then default to -40F/C.....thus, during the START mode, richer fueling immediately. I'm thinking that the ECU cuts OFF the GP operation during the START mode. However, if it's a hot start problem, GP use isn't a matter of concern!

The CTS has two functions (two separate circuits; engine temp (G62 sensor) info to the ECU and the other is engine temp (G2 sensor) info to the temp gauge in the cluster).

G62 circuit (in the same CTS unit and same connector) has one wire going to T121/112 on the ECU and the other wire goes to T121/104 on the ECU.

Either one of those wires could be tapped for use of the relay. In fact, the relay could be placed on the firewall just over from the end of the TDI head (Talking Vanagon set-up) fairly close to the CTS/connector/wiring. However, tapping and using an X circuit for positive power to the relay would have to be from under the dash up front. There are no circuits in the rear of the Vanagon that are related to the X circuit unless they have been turned ON.....tail lights, license plate light, marker lights, etc.

Of course, as discussed in the link in your post and by others, an ECU Tune would solve the problem totally!

Bummer about the clutch jamming the bellhousing. I recall that something needed to be removed from the pressure plate. Some tangs or something. Can't be of help since I am still running the stock clutch.

Ok, we are back from our weekend camping trip in Northern Florida. I don't post when we are out of town for obvious reasons, but I was driving the van last week to work to be sure it was ready for our trip. Here is what I have determined now that I am listening for it.

The new battery has for now solved the problem of a not hot start, but comparing the cranking revolutions to a cold engine vs a hot engine, the starter cranks quite a bit longer before it starts hot. That said, the new battery did crank the engine past the threshold of 250 rpm quicker, so it did always start.

I like the idea of a relay/resistor for now. It should give me a sense of how it will start with a tune. I would like to hold off on the tune a bit longer until I decide if I am going to upgrade my turbo. Unrelated, I am tripping the P1403 EGR code on cold start up and driving off. I had to reset the ECU probably about 4 times over the last week, so it would be nice to have that mapped out of the ECU too. I have the adaption set as high as I can for it. mark

rsxsr said:

I like the idea of a relay/resistor for now.

Click to expand...

The Hamman mod? Set up with a relay it works awesome.

Andy, I also had to knock down those two tabs on my clutch's pressure plate. If I remember right, I also ground down some spots inside my bell housing. I could not perceive any vibrations or ill effects of doing this.

The bright marks on your bell housing, in my experience are the areas that you need to ever so slightly trim down.

Hasenwerk said:

The bright marks on your bell housing, in my experience are the areas that you need to ever so slightly trim down.

Click to expand...

David it is good to know that only a small amount of material has to be removed. I was concerned that this would be a long drawn out process of hit or miss!

If I hadn't been hit with this mid-winter crud cold, I would have had finished the job by now. I am much better this morning and feel like tackling the job today.

I'll post results later today!

Edit: Alright, the transmission is in.. I had to grind the bell housing in four different places as well as knock down the two V-shaped tabs on the pressure plate (it was good to have an extra bell housing to work with). Since this job also involved doing a TB replacement (over a week ago), I need to start the engine and tweak the timing. However, while I got it up on stands, I'm going to install the front Sway Bar... Yeah, I had some problems with it and pulled it before I went to the TDI Fest. Also, while it's in the garage, I'm going to go ahead and install the relay on the CTS circuit. I believe the relay will allow me to program the ECU back to manual transmission. In another post, later tonight, I'll post pics.

Okay, as the edit in the last post said, I got the tranny up and in....everything connected, bolted, etc.

I had issues with the wiring for the Engine Temp Sensor relay power circuit and did not have time to install the front sway bar. More about that problem below.

Anyway, here are a few pics of the Bell Housing, Pressure plate, etc.

Below, is a pic showing the approximate distance from the pilot shaft over to the area where the pressure plate was making contact with the bell housing. (shiny spots)


Below, in this pic, you can see that five inches is to the outer edge of the area of the pressure plate where it was making contact with the flywheel... Also, notice there toward the bottom of the pic is one of two V-shaped tabs. I knocked those down a wee bit. (notice, I had to use the ALH dust shield between the engine and bell housing, worked fine)


Below, in this pic you can see the "spots" where I had to remove material from the bell housing to allow clearance for the pressure plate. The far left center is where the V-shaped tabs where making contact.


Below, is a close-up, left side of the bell housing looking toward the front of the Vanagon.


Below, is a close-up, right side of the bell housing looking toward the front of the Vanagon.


Below, is a close-up of the pressure plate showing the two V-shaped tabs after I knocked them down just a wee bit. (foregournd -background)


........................................................................................................................................
The following three photos pertain to my efforts to install a Relay in the Coolant Temp Sensor (CTS) circuit.

For Ignition power to the Relay, I had to run another circuit. I didn't want to just "hang" a wire from the dash under the Van to the rear. So, I attempted to "squeeze" one more wire into a small polyethelyne tube that already had 7 wires in it. I sort of screwed up and almost didn't accomplish the goal (long story).

Below, is a pic of the wiring schematic of the CTS circuit. Notice that the ETS is actually two sensors. G62 provides data for the ECU and G2 provides data to the Cluster for the Temp Gauge.

From the CTS connector, I will be installing a Relay in the circuit coming off #4 that goes to T121/104 of the ECU (ECU is represented by the dark bar in background). The circuit will be closed (normal) when the Ignition is ON. The power for the Relay will come from an X Circuit at the dash. X Circuit current is cut OFF during the Start mode of the Ignition.....thus, the Relay will open and the CTS can no longer send the ECU a reading. Then, the ECU will default to a reading of -40F/C. Next, it will respond by. increasing the fuel amount during START. (same as unplugging the CTS)


Below, in this pic, you can see that I have pulled the connector to the CTS and peeled the four wires out of the protective cover.


Below, in this pic, you can see the wire that will be cut for re-routing thru the Relay. I have not finished mounting the Relay nor completed the circuits.

Andy, I have not added a relay yet. I was thinking it through and am leaning towards a manual pushbutton switch. Here is my rationale. My engine always starts fine when it is at ambient temp. It is only when the temp is above, based in the info, 130F that it cranks for an extended period of time. By using a relay, it appears to be adding resistance to the circuit, not providing resistance. So, regardless of ambient temp, with a relay, the CTS would always be reading colder than it was. Maybe not ideal. I don't really know.

My next step is to replace the battery cables. They are 30 years old. Adding a power relay off the ignition switch to power the ECU seems to have made a good difference too. My scan gauge shows much higher voltage at the ECU now. In hindsight, I probably should have done that originally. mark

Well, I did get the Relay installed in the CTS circuit last evening (pics too). However, I have not tested it yet. While the Van is in the garage, I intend to address a few other items as previously discussed (sway bar for one and oil pressure gauge issues).

I was unable to work on the project today due to being in court (reference the high speed chase back right after Labor Day. page 48, Post #717). I have a Volunteer Fire Department Board meeting tonight at 6:30 which pretty much finishes this day.

So, hopefully I can get serious tomorrow and Wednesday. The oil pan thingy is still a monkey on my back and I've not fully desided how I will address it.

3rd ime Charmed!

Wow!

As they say, "third time charmed." Yes, I have to remove that darn transmission again.

I spent a few hours today replacing tidbits with the wiring, dash, cluster, etc., and then decided I'd go ahead and start the engine. Remember, it hasn't been started since the TB job a couple of weeks ago.

I did re-check the physical timing just to make sure I didn't screw-up. Everything was just fine. Flywheel on the mark and the IP pin slipped right into the hole snugg!

Well, the pressure plate still makes contact with the bell housing! Ouch! It takes more muscle than I have to rotate the engine with a breaker bar at the crankshaft. The starter and battery were a little pissed to. It's probably a good thing it didn't start.

It will probably be Saturday before I'll have time to get back to this problem.

rsxsr said:

By using a relay, it appears to be adding resistance to the circuit, not providing resistance.

Click to expand...

I think that if you use a relay with both a NO (normally open) and an NC (normally closed) circuit you can provide resistance, and not add it.

jackbombay said:

I think that if you use a relay with both a NO (normally open) and an NC (normally closed) circuit you can provide resistance, and not add it.

Click to expand...

Jack are you sure? I poured over the few threads and diagrams. I then drew out my own relay diagram. Even though you are toggling between normally open and normally closed, the diagrams I have seen are placing the resistor between the ECU and the CTS. So if the CTS value was say 15K ohms and you add 10K ohms while cranking you have a total of 25K ohms. I think if you wired it so the one end of the resistor was grounded and wired it so that when cranking the CTS would be bypassed and you'd have a 10K ohm resistance when cranking, not the total. That is why I referenced adding vs providing. I have only thought this out, I have not actually applied it though. markw

Update on flywheel/clutch

Well, today at 1:00 pm was the first time I've had an opportunity to work on the Vanagon in several days.

I pulled the tranny and found the problem. There wasn't any rubbing on the flywheel at all. The starter was rubbing the flywheel. I had to grind it down. I'll post pics later tonight or tomorrow.

Also, I think the relay for the CTS (Coolant Temp Sensor) must be working. The engine fired up almost immediately. The battery is a little weak from sitting for almost a month plus as you may recall, a few days ago I tried to start the engine with the flywheel rubbing and I suspect that sapped a little current out of the battery.

Okay, I need to go check and set the timing. Remember, this endeavor has not only been a flywheel/clutch job, but a TB job too. Oh, the rattle in the engine is gone. So, that large roller with the obviously bad bearings was the culprit. (Wow, and just think, I drove it to Ypsilanti, Michigan as well as numerous weekend excurisions.)

rsxsr said:

I think if you wired it so the one end of the resistor was grounded and wired it so that when cranking the CTS would be bypassed and you'd have a 10K ohm resistance when cranking, not the total. That is why I referenced adding vs providing.

Click to expand...

Wiring it this way would always give you 10k while cranking, so you would be "providing" a set resistance to the ecu instead of adding to the signal from the CTS. It has been a while since I though about all this though, I set up a simple button in a friends 99.5 years ago and later I had wished I had spent the time to set up a relay and though it was possible to do it as I describe, but maybe I got something mixed up in my head.

Okay, I did not have to set the timing. It was just slightly above the mid-line in the graph with engine up to 85.5C (remember this, the Timing).

As I stated in my last post, the engine fired-up almost immediately. It actually starts really good, even when the engine is fully warmed up.

But ......... here are the DTCs (Diagnostic Test Codes).

This code is a result of, using VCDS, I changed the ECU to see my tranny as an automatic (discussed in previous posts). Which always kicks-on the CEL with each start of the engine even if I delete the code.
18034 - Powertrain Data Bus
P1626 - 35-00 - Missing Message from TCU

The two codes below are because of the Relay I set-up on one of the circuits of the CTS that goes to the ECU (see recent previous posts for pics and other details).

16512 - Coolant Thermostat Valve (N214)
P0128 - 35-10 - Temperature below Control Range - Intermittent

16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 35-00 - Signal too High

I'm not sure where N214 is located, but I am under the impression that it pertains to the CTS. I did a Google search and there were a good number of links back to the TDIclub.

So, it looks as if I will have to look into what Mark (rsxsr) and JackBombay are discussing related to resistance in the circuit to fool the ECU rather than a total disconnect during the starter mode.

Now, remember my Timing above...... Well, if the CTS is sending the wrong info due to resistance (the Relay, two wire splices, two plug connectors, etc.), you would have to question the accuracy of the timing graph. Right?

Here are a couple of pics relating to the Relay.

In the pic below, you can see where I spliced in a length of wire for the circuit coming off Pin 4 of the CTS connector (I used the same gauge wire and color scheme). Everything is tucked away below and behind the head.


Below, is a pic of the relay mounted on the left side of the firewall of the Vanagon engine bay. The dark thingy in the foreground right (out of focus) is the CCV puck on the valve cover of the engine. The two wires going off to the right go to the CTS and ECU. The other two wires provide power/ground to the Relay from an X Circuit at the dash (see previous posts for the discussion).

Okay, here is an update/report on what was "locking" up the engine/flywheel (see previous posts for more details).

When I dropped the tranny, I could not see any place that the pressure plate was rubbing the bell housing....... I was really scratching my head. Then I picked up the starter...there it was.

Below is a number of pics relating to my finding and fix.

Below, self explanatory.



Below, another angle.



Below, material removed.



Below, in this pic you can see where I "marked" the area with a Sharpie then re-installed the starter to see if it was still rubbing..... see the area to the right of the marked area? At the end of the other arrow..


Below, another angle.



Below, these marks did not have to be ground off.........works.



Below, in this pic of the flywheel, you can see to the right of the teeth where the starter was rubbing. Also, see my fabricated timing mark. It is also marked on the pressure plate with a deep V.

Good work on the troubleshooting!!

N214 is the thermostat itself.

runonbeer said:

N214 is the thermostat itself.

Click to expand...

Well, you know, I had looked thru the circuit schematics (my ring-binder) and didn't find anything. And, last night when I prepared the post, my Bentley was out at the garage. Also, last night my brain was operating on a dose of diesel smoke/fumes...

................pause for more research.

Okay, it's pretty obvious that the ECU must have a programmed limit of temp range or sudden variations that causes it to throw DTC (CEL). I'm not sure whether or not there is a comparison between the two sensors (dash gauge circuit vs the circuit that goes to the ECU) or not. Based on the limited info in the schematics, I doubt that there is an exchange of info between the two sensors or by the ECU.

So, the Relay set-up I've done is not going to work without throwing a CEL at every start-up.

Maybe a double Relay that sends the data down a circuit with a set amount of resistance during the starting mode, as Mark and Jack have discussed, might work. Then when the ignition goes back to ON the Relay changes the circuit back to normal.................thinking out loud here!

Any thoughts?

Yeah, I know, the ECU needs a tune which will not only help the starting issue but dump the DTCs relating to the Air Bags, ABS, and brake pad sensor (no CEL on those, fortunately, but they are just there when a scan is done).

Okay, using my Thermo Electric Temperture Tester with three different temp sensors/probes and both Fahrenheit and Celsius options and Vag COM Diagnostic System (VCDS), I "played" around with the readings of various sensors about the engine this evening.

First, I taped one of the sensors from the Testor to the coolant flange near the CTS on the engine (engine cold, not running, inside heated building with ambient at about 70F). There was about 1 degree celsius difference between the two. Next, I checked the fuel temp using the same method. Since I only taped the probe on the side of the IP, the difference in the results was 3 degrees celsius (that's after waiting over a half hour). Seems the air temp sensor in the InterCooler reads a about 3 degrees celsius lower. But, the IC is slightly lower than the IP and is affected by draft.

Anyway, while I had VCDS running (ignition ON, but engine not running), I "tested" a couple of other CT Sensors to make sure the one in the engine was okay. I got the same readings.

Here is what suprised me big time (still scratching head), seems the coolant temp defaults to the Fuel Temp reading when the CTS is unpluged or the circuit of the CTS that goes thru the Relay is broken (off).

To varify, I placed a heat lamp along the side of the IP (opposite the electrical connector on the side of the IP) to increase the temp of the fuel. After about 20 minutes the fuel temp had increased by 6 degrees celsius and the control sensor for the Tester had a similar increase. During this time I left the CTS unpluged. The "reading" for the coolant temp increased as the fuel temp reading increased (remember, the CTS was unpluged). When I plugged the CTS back onto the sensor the reading changed to the coolant temp as previous.

So, what's going on? Did not running the engine have an affect on the CTS temp reading defaulting to the Fuel Temp reading?

Oddly, back in the fall, when I was unplugging the CTS to start the engine, ScanGauge was showing -40C and showed the DTC as posted below. I think not running the engine affects these readings.

As posted previously, below is the DTC reading when the Relay is activated by disconnecting and reconnecting it (same as start mode) or unplug the CTS.

16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 35-00 - Signal too High

Lastly, the OBD port at the engine bay is awesome (details of the OBDs are back in the July or August posts).

Well, I know that last post was complicated.... too much confusing detail.

So, here is more complicated stuff.

I'm going to try two Relays. (these are simple coil operated relays, with power ON or OFF operating them [closing or opening a circuit]) These two relays operate opposite of one another...... as follows.

Relay #1 (already in place). ............. Relay #2
-Ign Off, it is Off (open).................. -On (closed)
-Ign ON, it is ON (closed)................ -Off (Open)
-Ign Start Mode, it is Off (open)....... -On (closed)

Relay #2 (to be installed) It will use the same power source as Relay #1 (X Circuit).

The circuit from Pin #4 on the CTS connector will go thru each Relay in parallel (side by side).. The theory is that when the Ign is turned ON the data from the CTS will go thru Relay #1 but "switch" to Relay #2 in the "Start Mode".

Relay #2 will have a "Resistor" in the circuit to mimic a low temp reading from the CTS. (to improve starting)

The big question is whether or not the "instant" of switching will be detected by the the ECU, then throw a CEL.

This evening, I "tested" the resistance readings of the CTS from -5C up to room temp to see what Ohms resistor might work. Unfortunately, my Temperature Tester battery died during the procedure.

Here are some examples: -5c= 7,650 Ohms resistance, 0c= 7,000 Ohms resistance, 10c= 4,770 Ohmns, 20c= 2,650 Ohms resistance and so on! ......< Edit to enter the correct Ohms readings (I forgot to do "times" one thousand)

I'll do these tests again tomorrow and take the temp from below freezing up to engine full operating temp to see how the resistance changes in the CTS.

Andy, how about this. I am still thinking it through. Could you solder the resistor between 87a and 87 of a single relay. X circuit would be on 86, ground on 85. CTS on terminal 30 with the ECU on 87a. When energized the current flow would be through the resistor, but when power was taken away, the current would continue to flow through the resistor until 87a took over again. This could eliminate the "dead zone" but give you the enrichment. We are talking about milliseconds here. mark

Mark, that may work. However, right now, I'm stumped as to what Ohm resistor to use.

According to info from Dan (tech page). There's a pretty hefty swing in Ohms with temp change.

Here are some examples.

0 Celsius (32F) = 6500 Ohms

30C (86F) = 1500 - 2000

50C (122F) = 1000

80C (176F) = 275-375.

Those numbers pretty much are what I am getting using a CTS and testing it with Multi-meter, Thermometer and temp swings. Not totally scientific but close based on my other MM and Thermometer probes (feel okay with the comparison).

So, what Ohms resistance would be best?

Speculation, if there is too much resistance, the ECU may trip the CEL when the engine coolant is really cold? On the flip side, if it is not enough there may be no affect on a hot start.

I'm thinking that leaning toward a lot of resistance and work back down if necessary.