MAF and MAP and Iq Readings

[Ealerguy]

I have a 01 jetta tdi. (Rocket chip, pp 520's, cvt vent, egr race pipe, cat-less and soon to be straight pipe muffler) and ive been taking readings and trying to fix "little" issues with vag-com. There are just some things im uncertain of... The car has a lack of power (20-40hp), smokes at any throttle, occasional limp mode, lower mpg, and loud engine noise.

My MAF reading is: Specified around 850 constantly and the actual is 550-580 though out any rpm range. Is this bad for a MAF? What should both values read? What is the best MAF to buy and from where?

My MAP readings in group 11 show that the actual is always 100-300 short of the specified at any rpm and the graph of both never seem to get very "tall". I’ve recently tried to replace any vacuum lines that seemed bad.
Good? Bad? possible problems?

My IQ was at .8 to 1.0 at idle, which i know is off. I tried to bump it up and the most I could get is about 2.1. The car now sounds better and smokes less. However I’ve read it should be in the 3-5 range. I assume i need to perform the hammer method. What should be my Iq given my mods?


My timing was retarded beyond the range on the graph and soon I will be fixing this. Also, I will be running Seafoam through my injectors to clean them up a little.

What else should I check with vag-com or look into? Thanks for any help it is greatly needed and appreciated. I can post screen shots if needed.



Quick Info
Vacuum from the main line should be 25"+ using a mityvac.
vacuum into and out if the n75 solenoid should be around 25"
Make sure your vacuum lines don't have leaks and is routed correctly according to these diagrams: http://forums.tdiclub.com/showthread.php?t=290286
Places to check for leaks are the vacuum lines,vacuum pump twist connector (this is where my problem was), erg solenoid, asv solenoid, vacuum "ball" reservoir, and the turbo actuator.
Coolant temperature should be in group 1, 4th value or group 7, 4th value in vag-com, it should read somewhere 190-200ish in Fahrenheit once the engine has warmed up.
The MAF should be able to hit over 1,000 when floored if everything is correct.
The turbo actuator should be set to 3-6" to start and stop at around 18-20".
At WOT you want the n75 solenoid duty cycle to be near 70-75% or so from 3500-redline.
You can unplug your MAF to see if it helps the car run better.
You can also swap the egr solenoid with the n75 to see if this cures any or your problems.

 

[Seatman]

The maf sounds like it's been set to full in the mapping but the actual sounds low, the IQ at idle sounds way to high, out of range in fact, should be between 3 and 9. I suspect the turbo vnt is probably clogged too, not the vanes but in the back of them where the chemical cleaning doesn't reach.

Might be worth doing a log of 3 8 and 11 together from about 2000rpm in 3rd then a change into 4th at maybe 4000rpm then post those results up, should be someone around here who would be able to get something from them.

 

[Ealerguy]

What should the values for the MAF read and idle and full Throttle? When I unplug it, I don’t gain anything in performance or smoke output. Is there a manual test I can do on the MAF to detect if its within range?

I will perform the hammer mod to get the IQ within range. I will try for 4. What is recommended for a car with my mods? I would like to be in the middle of performance, mpg, and smoke output.

I had the turbo replaced about 8 months ago. Could the turbo already be clogged? I thought that having the egr and cvt removed would prevent clogs. What are the things that need to be checked if the turbo isn’t clogged?

I will try to post the log of the measuring blocks you told me to soon. I don’t really know how to do a log but ill try to figure it out. I know that vag scope shows the graph of the blocks. What boxes should I have checked to show on the graph so its not filled with extra data?

 

[Seatman]

I would expect the maf to be up over a 1000 when you're booting it anyway, mine does even though it's set to 850 in the tune.

The IQ at idle shouldn't really affect the performance much at all but should help clear up some smoke, I think aiming for about 4 just now would be a good.


Not saying your turbo is clogged, just a possible but if it's that new it probably isn't. It's a bit of a guessing game using your own knowledge and what the posters problems are, you just try to suggest possibilities.

Are you not getting any specific fault codes logged?

 

[Ealerguy]

The only code I get is for the glow plug harness. What I read yeas ago was that it's a very common problem and you don't need to fix it as long as your glow plugs still work. But I'm gonna check everything out with the glow plugs this week or next weekend. Thanks for all your help. I'll try to get a graph of acouple things soon.

 

[Ealerguy]

Here are some screen shots I took. I don't know how to use the log function on Vag-Com. :/
Below is my MAF readings

Below is my MAP readings


Here is my IQ values

Here is my Injector Quantity values

Here are the readings from 3,8, and 11 combined

To me it seems like my MAF,MAP,IQ, and Injector values are off. PLEASE HELP!

 

[Seatman]

The maf looks like the most likely suspect to me, I don't suppose you can borrow one to test? Also you could try unplugging it, see if that flat spot goes away, some cars do well with it unplugged and some are very sluggish but it should still be smoother which would also point to the maf. I think that would also account for the boost issue.

Did you check 13 at idle? It does look like two is doing much but I'm not sure how you use 13.

 

[Ealerguy]

I fixed the timing and the IQ (via hammer mod), I also ran seafoam through the injectors to clean them. Now I have a lot less smoke and the engine sounds much better. I still don't have the power I should. Tomorrow I will try to clean the MAF before I decide to buy a new one.

What should the MAF be reading at idle and at full throttle?
Did anything look off as far as my MAP readings?
What are other things I should be checking?

 

[Ealerguy]

I cleaned the MAF and it made no difference. I unplugged it and there was a slight difference, just barely. I will be buying a new MAF to test.

Also Since I’ve been tweaking everything, it seems my temp gauge is jumping all over the place and never actually hitting operating temp even though it has to be there and it blows very hot air. I read an article that there are two sensors for this, one for the ecm and one for the gauge is this correct? Should I replace both or just one?

Could this be causing any of my problems?

 

[Seatman]

Your boost looks a little low compared to spec but I still think it'll be the maf that's causing the main lack of power and flat spots.

It also sounds like your cts is on the fritz now too, see if it's throwing a fault, you can also check the temp in vagcom to see how stable it is, if it's ok then that would further point me to the cts as being funky, it has four pins, two do the ecu and the other two do the dash.

 

[Ealerguy]

No codes in the last two days? Please forgive me, I have no idea what the cts is or how to test it. Vag com reads about 137 in group 000 in the 9th box it was the only place I could find a ferenhite reading. I'll try to check it when it's actually jumping around. Should it read 190*? That's what my gauge always says when it's running fine. We will get all these problems sorted out one way or another!

Also I tried to test the n solenoid in group 011 by turning it on and off via vag com and I could not hear a difference in the exhuast. Should everyone be able to hear it?

 

[nexus665]

CTS = coolant temperature sensor. Should be in group 1, 4th value or group 7, 4th value...what you were looking at in group 0/basic settings, I dunno...

Yes, it should read somewhere 190-200ish in Fahrenheit once the engine has warmed up - seems you have more than one issue. Easy to change though - but you will need to drain the coolant or contain what spills when you swap it and refill...

Regards

 

[Ealerguy]

Just ordered the new MAF and CTS they will be here in four days. I will post new readings then.

Do you guys think I should do a coolant flush, the coolant has never been flushed and the car has 300k miles on her. If so can I just open the drain on the radiator and hook a hose to the overflow tank and let it flush with the car idling. Then let the water drain out, shut the drain and fill her up with coolant.

Also I ran basic setting-04 on group 011 so I could cycle the n75? Solenoid, I read I should be able to hear a change in the exhuast. I could not. Is this normal or should I be checking something else out?

Thanks again guys for sticking with me!

 

[Ealerguy]

Here is a picture of my car right after I started it.



Here is two pictures of my car fully warmed up.


2 seconds later...


And lastly here is a picture of my timing.



Who can tell me what the three different temperature readings in group 007 are?

 

[Seatman]

Your timing is a bit on the advanced side, I would put it more like 65 or 70 myself.

No idea on group 7.

I'd leave the engine off for flushing too, maybe pull the t-stat out too and swap it at the same time.

Regarding the cts, when it comes to replacing it the best way is to take out the clip, pull the sensor out with the plug still connected and make sure the rubber o ring is out too then pop the new one and o ring in, fit the clip then swap over the plug after.

 

[Ealerguy]

Thanks when I checked it last week it was retarded off the graph so I advanced it. When the engine is completely warm I think it's a bit better also I forgot to pick my model of car for the graph I believe that not having my car selected it makes it a little higher. Who ever had the car before me must of striped two of the bolts because they spin freely. Any idea what to do to get new ones in? I tried to use a flat screw driver to help pop them out while turning but it didn't help.

Also if I replace the termo. with a 195* or 205* hybrid would that help mpg?

 

[Seatman]

What bolts? The ones for the pump pulley? I'd seriously be concerned with fixing that one for sure! That could in theory prove to be a very expensive issue if left.

Maybe it's possible just to re tap the holes, getting them out though, now that's a different story. Other than the screw driver, vice grips and sheer determination I can't think of anything else.

It might even be possible to get a replacement hub, I'd think it'd be easy enough to mark the old one up then mark the new one to match to get it back in the same place within a hairs breadth. Not sure how you counter hold the shaft though but I think it's definitely something I would consider.

A bit of hassle now could save a lot in the future if it all went pear shaped and took out the timing belt.

 

[Ealerguy]

Okay! What about a 195* termo. or 205* hybrid?

 

[Seatman]

What's that?

 

[Ealerguy]

A higher temperature thermostat. I read it can increase mpg.

 

[Seatman]

Ah, I wouldn't bother, just a properly working one would be good.

 

[Ealerguy]

Here are my new readings with a new MAF.


And here is my MAP reading

The car still has more power with the MAF unplugged. Could I have gotten a bad MAF? It reads 475~ at idle. Also, my MAP actual never meets my specified.

What else should I be looking at?

 

[Seatman]

Is that with your foot to the floor in 3rd?

 

[Ealerguy]

Te first MAF reading is me shifting 1st - 3rd foot to the floor. The second is me in 2nd keeping rpms at 4~k.

The MAP reading is me once again shifting 1st - 3rd foot to the floor, except of the fact once I shifted in 2nd I waited a couple seconds to floor it again.

I can always redo any test you want me to do any way you want.

 

[Seatman]

Somethings not right, the maf readings should be up over 1000 with foot to the floor, I wonder if it is a bad maf? I have seen people get bad reman bosch ones often enough. A lot of the cheaper ones are even worse, can be very hit and miss.

Usually test from about 2000rpm in 3rd up to about 4000rpm then I change to 4th for a little, gives a longer reading. Most common too is to log 3, 8 and 11 together.

 

[Ealerguy]

When I log 3 8 & 11 what are the options/values that I want to show up? When I log them it's just a huge mess on vag scope. I don't know how to use a log.

 

[Seatman]

Measuring blocks, select groups 3 8 and 11 then hit the log button, when you're ready press start and go for it then once you've slowed enough hit stop.

 

[Ealerguy]

Here is my log of 3, 8, 11.

 

[Ealerguy]

Anybody please feel free to chime in. My last post was a log of groups 3, 8, and 11 in 3rd gear through 4th via vag com. I have a new MAF and the car runs slightly better unplugged. I'm not getting nearly the power I should be. Any help would be greatly appreciated!

 

[Seatman]

Definitely no boost leaks? I mean the boost almost gets there at 3500rpm but even then it's well below spec. Maybe need to tweak the actuator rod, you'll need to double check but I think you'd need to shorten it.

Not 100% sure on the maf but I still don't think it's getting as high as it should but whether that might be caused by the boost or something I don't know.


Has the car always been like this since it got the tune or is this a more recent thing?