OK so I have a really annoying problem that has been going on for a while now and i cannot figure out what it is. So for a long time now whenever i get in the 1500-2400 rpm range the check engine light comes on and as soon as i take my foot off the gas or speed up past that point it goes away and it has never stored any codes, the dealership could not figure it out either. So now for the past couple of weeks the truck has been stalling about 15-20seconds after i start it, but it only stalls if i leave the truck off for more than 20miniutes or less that 2 hours give or take a few miniutes, then after it stalls it takes about 10-15 seconds of cranking to get it started again unless I put it in drive start the lift pump for a few seconds then back into park then it starts in about half the time.
I just replaced the fuel filter and the pmd a couple of weeks ago, and the lift pump works fine. The injection pump was replaced a coulpe of years ago and the truck now has 253,600 miles on it.
Now I just checked the codes again an now it is storing codes, codes 35, and 36 both injection pulse with error (response time long and short)
Has anyone had a problem like this before? anyone know what is going on? I would really like to get this resolved.

OK so I have a really annoying problem that has been going on for a while now and i cannot figure out what it is. So for a long time now whenever i get in the 1500-2400 rpm range the check engine light comes on and as soon as i take my foot off the gas or speed up past that point it goes away and it has never stored any codes, the dealership could not figure it out either. So now for the past couple of weeks the truck has been stalling about 15-20seconds after i start it, but it only stalls if i leave the truck off for more than 20miniutes or less that 2 hours give or take a few miniutes, then after it stalls it takes about 10-15 seconds of cranking to get it started again unless I put it in drive start the lift pump for a few seconds then back into park then it starts in about half the time.
I just replaced the fuel filter and the pmd a couple of weeks ago, and the lift pump works fine. The injection pump was replaced a coulpe of years ago and the truck now has 253,600 miles on it.
Now I just checked the codes again an now it is storing codes, codes 35, and 36 both injection pulse with error (response time long and short)
Has anyone had a problem like this before? anyone know what is going on? I would really like to get this resolved.

Question 1: Did you put a brand new PMD on it and where did you mount it? Your signature says that it was relocated, but to where?

Questions 2: What test(s) did you perform to determine that the lift pump is working fine?

Regards,

I put on a brand new PMD and mounted it in the bumper with a new #7 resistor and a blue heatsync. I know the lift pump is working because i can hear it come on, also because the way i get the engine to start easier after it stalls is I put it in drive and turn the key to start and turn the lift pump on for a few seconds. so it works fine. it was also replaced not to long ago

As you said, it is stalling. So make sure you check your OPS also. I notice this is a continuation of your older thread and you have not reported back what you did with OPS. OPS controls the LP when it is running, while the relay control the LP during crank. So you can start but stalling, that means the OPS may be bad and causes the LP not to run.

If that is not the case and you have a new PMD, it may be something else. IP? Make sure the extension cable is not rubbing against anything.

Well it seemed to run work fine, but I will check it again, just weird that it only does it after it has been off for more than 20 miniutes and less than 2 hours 20 seconds after it starts, maby it is becasuse it was hot or something?

Don't be sure your lift pump is working just because you hear it.
My previous one, a HO ACDelco was purring like a herd of kitten and I was pretty confident.
Then, I install my gauges and could see.... nothing, no psi at glow cycle, at idle, nor at WOT.

The pump was purring but was shot---

Don't be sure your lift pump is working just because you hear it.
My previous one, a HO ACDelco was purring like a herd of kitten and I was pretty confident.
Then, I install my gauges and could see.... nothing, no psi at glow cycle, at idle, nor at WOT.

The pump was purring but was shot---

X2....I thought mine was working fine, until I opened up the T-valve and noticed that it was just dribbling out. Sounded fine tho.

x3, mine was purring, except it was hard to start and stalling. Changed the battery, fuel filter, OPS, etc. Before deciding it was the LP.

ok well i will test the lift pump again and see, I just figured since i could hear it and it was not very old it was working fine, i will also check the ops tomorrow, I am also going to put some oil in the fuel along with the diesel service which i have been using and see if it fixes the check engine light.

It's a 2 for 1 test. If you have no fuel pressure when you turn the key - before the engine starts - then your lift pump isn't pumping. (OPS may or may not be OK).

If you have pressure before it starts but it falls to zip when the engine starts your OPS is shot.

ok well i will test the lift pump again and see, I just figured since i could hear it and it was not very old it was working fine

It was my Heath LP, and it only lasted about 4 months/15,000km.

...If you have pressure before it starts but it falls to zip when the engine starts your OPS is shot.

Not true for the OBDI (1994 and 1995) trucks. On these there is no "pre-start" lift pump operation of the injection pump.

Regards,

My LP does indeed run during the WTS cycle ('95).
PO did do some extra wiring though, or the bucket truck co did.

I defer to Mr. Goldsburg, but I'll most likely leave mine as is - Seems like a good idea to have it running pre-start.

My LP does indeed run during the WTS cycle ('95).
PO did do some extra wiring though, or the bucket truck co did.

I defer to Mr. Goldsburg, but I'll most likely leave mine as is - Seems like a good idea to have it running pre-start.

probably they wire a diode from the glow relay to the lift pump relay to make it work while WTS cycle----

Mine doesn't run till the ignition switch is in start position. Then OPS takes over.

Mine doesn't run till the ignition switch is in start position. Then OPS takes over.

Correct. Put the truck in drive (so the Neutral Safety Switch won't let the starter engage) and turn the key ... you should get LP action.

McMatt: use a pressure gauge, as was indicated in your previous adventure. They're cheap, easy to hook-up (put the hose right on the water drain, off the brass T-handle), and are an invaluable diagnostic tool.