1993 toyota sr5 ALH tdi swap (3 week project)

[JaysinSpaceman]

I have to say that a selectable locker is much better for a vehicle that is driven on the street. I haven't had a selectable locker myself but I have had a regular one and they wear tires fast and they suck in the snow on the highway. Selectable gives you an open diff for the street and a locker for offroad, the best of both worlds. When I get to that point on my truck I will be finding an e-locker.

Jaysin

 

[01greenjetta]

http://www.marlincrawler.com/differential/complete/toyota-electric-equipped

Good info about e-lockers. Ready to install 3rd members too!

 

[dustystdi]

Well the truck has been doing great. Lots of hard miles have been put on the truck. As of a week ago it started acting up.

The problem:
I was pulling off a dirt road onto a paved road. I dumped the clutch and held her to the floor to see what it would do with my 33x12.50 tires and sure enough it got side ways. It was doing awesome and then all of a sudden it practically fell on its face. After that, I struggled getting down the road to my destination and at the same time is sounded like it had an extremely small boost leak. It never affected the way it idled. Meaning i never once thought i would be stranded on the side of the road. It runs great idles great and as long as you don't press the gas pedal to far it runs great all the time. But if you try to accelerate fast i cuts out and jumps around.

I thought that it was running out of fuel so i checked to see if my stock Toyota fuel pump was still working. I found out it was not so i put a cheap 12V fuel pump under the hood but it didn't fix the problem.

Next I started looking for a boost leak. I found one where i mounted my MAP sensor. I cleaned and resealed it and started my 100 mile trip. I took it easy because i didn't want to break down. It ran perfect for the first 75 miles and then out of nowhere while cruising at 63 mph is just started cutting out. I just left my foot in the same spot on the gas pedal. The cutting out would come and go and only lasted a couple seconds. It continually got worse by the time i got home to where i could hardly accelerate. I could only push the gas pedal about 1/2 inch down.

It sat overnight and i drove it the next day but i couldn't get it to repeat the problem. I guess i could have fixed it as long as i don't drive over 75 miles at a time but i doubt it.

Does anybody have any ideas??????

 

[Growler]

sounds like limp mode. next time it does fall on its face, turn the car off, then back on and see if the power comes back immediately.

if it does, you are falling into limp mode. which means your boost isnt being properly controlled meaning you are making too much or too little boost for too long and the computer is pulling power to reduce the chance of damage.

do you have any stored codes? or is your truck all mechanical and no longer has the computer controlled IP in it?

 

[dustystdi]

I am running computer still. And i agree that it was my first thought that it was going into limp mode. But it doesn't seem to change anything when I shut off and restart.

It is not showing any new codes. I always have at least 5 codes. But no new ones. They are just like EGR, instrument cluster, etc. It has been the same codes since the first day i cranked it so they don't really have anything to do with this problem. I was wondering about a TPS maybe?

 

[jimbote]

do you have your brake signal going to the ecm?....maybe you can recreate by lightly holding the brakes while under power

 

[dustystdi]

I fotgot to mention that I tried that also. I have the brake switch connected to the wiring harness but not to the pedal. So while driving down the road i tried to press the brake switch but it didn't seem to do anything at all, as far as how the truck runs.

 

[X@V]

MAF... it's why I'm performing some MAF delete.

 

[dustystdi]

This is some graphs that i took using Vag-Com. Int the first graph: red line RPM, green line MAF, blue line MAF ACTUAL.

In the 2nd graph: light blue/purple line THROTTLE POSITION, red line MAF, yellow line MANIFOLD PRESSURE, green line ATMOS. PRESSURE.

In the 3rd graph: red line MAF, yellow line MANIFOLD PRESSURE, light blue/purple line THROTTLE POSITION.

 

[dustystdi]

MAF... it's why I'm performing some MAF delete.

How are you doing the MAF delete?

 

[dustystdi]

Well since yesterday afternoon when I reinacted what started the problems originally, which was: on a dirt road I stopped and put it in first and tried to see how many gears I could spin the tires through. I got into 2nd gear and on the Toyota tach it hit about 4200 rpms which I figure is Red lining because the tach revs up exponentially faster then the actual rpms. I found this out using vagcom.
Anyways after hitting 4200 the problem is really bad again. Now every time I crank it and try to drive I can barely get down the road because of the throttle jumping all around.

 

[dustystdi]

Well is all fixed now. The problem was it wasn't getting any fuel. Combination of the sock filter in the tank getting clogged and the stock Toyota fuel pump to hard to pull diesel through.
The fix- removed stock Toyota fuel pump and replaced it with a piece of tubing, then mounted my external fuel pump on the truck frame right by the fuel tank. It now runs better then i think it ever has. I think it has always starved for fuel at high rpm's. Thanks for the help DanG144.

 

[FredS]

Is the lift pump really needed?

 

[Whitbread]

Lift pumps help out quite a bit on any modded Tdi.

 

[FredS]

thanks Matt. I'm in the early stages of my conversion, so good to know I need some low pressure pump to feed the IP to make it run that much better.

 

[JaysinSpaceman]

Dusty,

What lift pump are you using here?

Thanx,
Jaysin

 

[dustystdi]

I am just using a facet fuel pump. Mounted right next to the stock fuel tank and pumping up through the stock Toyota fuel filter it pumps about 2liters a minute. Obviously it needs it from what I'm told. I haven't had any problems.

 

[DanG144]

If the lines are properly sized and sealed, no fuel pump is needed for an ALH.

But a good fuel pump can prevent many issues, especially in a high output diesel.

I am not sure that I would consider a 2 lpm pump adequate for full performance. Check to see if the inlet line of your Injection pump goes to a vacuum at full throttle, full rpm. If it goes to more than 4" hg vacuum, I would put a larger flowrate pump on it. If the pump suction goes to more than 8" vacuum, you might be better off with a large open line than with an undersized pump.

I have seen other system designs that use a small pump for priming and low rpm operation, with a large fuel line in parallel with a check valve in it. When more flow is demanded than the pump can supply, the check valve opens and the pump vacuum drags what it needs.

I do not know the flow that an ALH IP has under full rpm full throttle conditions. Does anyone else?

People interested in optimum performance use a lift pump that maintains a positive pressure to the IP at all times, under all conditions. This ensures no vapor bubbles or air entrainment that can limit performance.

 

[dustystdi]

If the lines are properly sized and sealed, no fuel pump is needed for an ALH.

But a good fuel pump can prevent many issues, especially in a high output diesel.

I am not sure that I would consider a 2 lpm pump adequate for full performance. Check to see if the inlet line of your Injection pump goes to a vacuum at full throttle, full rpm. If it goes to more than 4" hg vacuum, I would put a larger flowrate pump on it. If the pump suction goes to more than 8" vacuum, you might be better off with a large open line than with an undersized pump.

I have seen other system designs that use a small pump for priming and low rpm operation, with a large fuel line in parallel with a check valve in it. When more flow is demanded than the pump can supply, the check valve opens and the pump vacuum drags what it needs.

I do not know the flow that an ALH IP has under full rpm full throttle conditions. Does anyone else?

People interested in optimum performance use a lift pump that maintains a positive pressure to the IP at all times, under all conditions. This ensures no vapor bubbles or air entrainment that can limit performance.

I would like to know what kind of flow is required for the alh at full throttle. I was assuming that 2 liters a minute was pretty good. How would I check to see if inlet line goes to vacuum?

 

[DanG144]

I do testing like this in a pretty simple fashion.
Hook up a fuel gauge (usually 30" vacuum to 10 psi range, or 30" to 15 psi) using a plastic or brass tee in the fuel line between the filter and the pump supply. Put a 7 foot long piece of hose on the fuel gauge so it can be routed into the cabin.

Get a passenger to watch the gauge - or you will wreck your truck. Seen it happen at a gtg.

Go for a ride, get in 3rd gear and floor it. First and second are too rapid - this gives you a couple of seconds between 4000 and 5000 rpm with it also at full throttle. The passenger just reads the gauge.

Measuring flow is about the same, but less precise and much messier. Tee on the return line. Guy in the bed with a 5 gallon fuel container and a one gallon one. At 4k he swaps the line to the smaller container and starts a stop watch. At 5k he swaps it back and reads the time. Pedal floored the entire time. Then you measure the amount caught and divide by the time the hose was in the bottle. This gives you the average flow rate, so it will be close to right at 4500 rpm. Then you buy a fuel pump that flows more than this when you measure its flow rate.

Measuring flow must be done on an ALH engine AFTER you keep a positive fuel pressure on the supply. If you measured yours now it would show a flow rate of 2 lpm. If you measure it on an engine with a vacuum type suction, it may also be flow limited by the suction line capability.

The PD fuel lift pump has a flow rate of right at 3.5 lpm, while still putting out a positive pressure (which means the eductor in the assembly still has some flow). It will pump 4.75 lpm if you have no flow to the eductor (as if an IP was pulling on the fuel line - it would read zero psi and provide 4.75 lpm.)

Most people with ALH engines of under 200 hp and 5000 rpm redline find the PD lift pump supplies enough flow to ensure full high rpm performance, but I never saw a report of flow or pressure.

A dyno or rolling road would greatly simplify taking the flow and pressure measurements.

 

[DanG144]

I do testing like this in a pretty simple fashion.
Hook up a fuel gauge (usually 30" vacuum to 10 psi range, or 30" to 15 psi) using a plastic or brass tee in the fuel line between the filter and the pump supply. Put a 7 foot long piece of hose on the fuel gauge so it can be routed into the cabin.

Get a passenger to watch the gauge - or you will wreck your truck. Seen it happen at a gtg.

Go for a ride, get in 3rd gear and floor it. First and second are too rapid - this gives you a couple of seconds between 4000 and 5000 rpm with it also at full throttle. The passenger just reads the gauge.

Measuring flow is about the same, but less precise and much messier. Tee on the return line. Guy in the bed with a 5 gallon fuel container and a one gallon one. At 4k he swaps the line to the smaller container and starts a stop watch. At 5k he swaps it back and reads the time. Pedal floored the entire time. Then you measure the amount caught and divide by the time the hose was in the bottle. This gives you the average flow rate, so it will be close to right at 4500 rpm. Then you buy a fuel pump that flows more than this when you measure its flow rate.

Measuring flow must be done on an ALH engine AFTER you keep a positive fuel pressure on the supply. If you measured yours now it would show a flow rate of 2 lpm. If you measure it on an engine with a vacuum type suction, it may also be flow limited by the suction line capability.

The PD fuel lift pump has a flow rate of right at 3.5 lpm, while still putting out a positive pressure (which means the eductor in the assembly still has some flow). It will pump 4.75 lpm if you have no flow to the eductor (as if an IP was pulling on the fuel line - it would read zero psi and provide 4.75 lpm.)

Most people with ALH engines of under 200 hp and 5000 rpm redline find the PD lift pump supplies enough flow to ensure full high rpm performance, but I never saw a report of flow or pressure.

A dyno or rolling road would greatly simplify taking the flow and pressure measurements.

 

[dustystdi]

Is this the type guage you are talking about using?

http://www.harborfreight.com/fuel-pump-and-vacuum-tester-93547.html

 

[DanG144]

yep, that would work.

 

[dustystdi]

If i already know I need more pressure, what pump is a good one to install?
?
http://mercedessource.com/node/9378
?

 

[DanG144]

Dusty,
You really do not need a higher pressure pump; I do suspect that you need a higher flow pump.

I would not source another pump until you had more information.

If you do put one on without doing any testing, I would get a pump that could put out at least 3.5 lpm. You do not want more than 15 psi discharge pressure, and it can be less than that.

 

[dustystdi]

This is the exact fuel pump that I have.

http://www.facet-purolator.com/inde...ent&task=category&sectionid=7&id=14&Itemid=36

 

[dustystdi]

What is a good high flow fuel pump but not to high psi?

 

[DanG144]

This is the exact fuel pump that I have.

http://www.facet-purolator.com/inde...ent&task=category&sectionid=7&id=14&Itemid=36

That goes to a page that lists many pumps. Which number do you have?

 

[DanG144]

Dusty,
As I said, I would do a test to measure flow before I spent my money. Put a boat tank on the cab roof full of diesel. Run a 5/16" or 3/8" hose to the fuel filter and IP.
Have a guy measure the flow in the back as mentioned above.

If you are not going to do that, then
http://marineengineparts.com/shopsite_sc/store/html/page81.html
perhaps the carter 4389 would be a good choice.

 

[dustystdi]

I honestly couldn't tell you because I can't read the label. I know it's a 12 volt and it only has 1 wire which is positive. It looks like the picture. When I calculated the flow without running through a filter it took 3 min. And 52 seconds to pump about 2 gallons.