02 Wont start when hot.

HaysKSFirefighter · Jul 16, 2011

Alright gentlemen. Myself and vanderchevy18 have been fighting with this issue for almost two months now. My pickup (mods in sig) has been having a start issuue, it will fire up within a second when cold but when hot it wont fire at all. It has new sticks and three new cps', thhree differennt ipr's and cores, all orings are good, hpop resi full, pulled icp sensor, all made no change. Here's the thing we don't understand, when cranking today the oil gauge showed no pressure, we pulled the plug on resi and cranked and nothing came out the open port. Correct me if im wrong but shouldn't the oil have shot out of there? Does this sound like a pump issue?

Any hellp or ideas is appreciated.

Sorry for the typos and such, my droid is freaking out on me.

SouthFlstrokin' · Jul 16, 2011

How is your starter Or batteries?

G Racing · Jul 16, 2011

Sounds like you could have a bad or weak lpop. You should have had some oil come out of the sensor hole. You can put a mechanical gauge on it and see what pressure you actually have. The next time it is hot and won't start jack the back end up as high as you can with a floor jack and see if it starts.

vanderchevy18 · Jul 16, 2011

Batteries are new.

Well I thought it was lpop but it runs fine with good pressure every other time and it starts right up when cold. Kinda opposite of the norm! LOLLOLLOL

We'll try that tomorrow.

vanderchevy18 · Jul 16, 2011

Just another piece of info. Could probably be coincidence though. It didn't do this before the srp1. After the srp1 it would always start but when it was hot it took about 10 seconds. When the stage 1's went in it started not starting at all while hot. Chip, no chip, new sensors, no codes that scream what it is either..... Well there is one. Oil temp sensor showed bad but it still wouldn't start with it unplugged or a new one.

Lowdown89 · Jul 16, 2011

My truck was doing that before the engine rebuild, just at random ass times when it was hot and I replaced my LPOP with the melling unit and it started fine after that all the time

HaysKSFirefighter · Jul 16, 2011

I just have no idea what it could be. If the lpop was bad then I would have no pressure at the port but my srp1 should have drained the resi, I don't think it did, did it chris?

vanderchevy18 · Jul 16, 2011

No. Resivour was full each time.

vanderchevy18 · Jul 16, 2011

What about electrical? Windows wont work for a couple minutes after start even though the relay has been replaced.

I don't know. I should waited to buy my gtx and got AE instead! Lol!

HaysKSFirefighter · Jul 16, 2011

vanderchevy18 said:
What about electrical? Windows wont work for a couple minutes after start even though the relay has been replaced.

I don't know. I should waited to buy my gtx and got AE instead! Lol!

The window thing is hit or miss...it only happens sometimes.

Don't you dare say that! You were as excited to order that damn thing as you were the night your rig fired up after the build...We'll have AE, hopefully sometime soon cause this is getting ridiculous :doh:

Tom S · Jul 16, 2011

Just another piece of info. Could probably be coincidence though. It didn't do this before the srp1. After the srp1 it would always start but when it was hot it took about 10 seconds. When the stage 1's went in it started not starting at all while hot. Chip, no chip, new sensors, no codes that scream what it is either..... Well there is one. Oil temp sensor showed bad but it still wouldn't start with it unplugged or a new one.
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If it does not make 500psi or so or low pressure oil it is not going to fire. I was under the impression that the reservoir did not have to be under pressure only filled with oil for start up. The qoute above is a giant red flag for me. I think the pump is not making any pressure with hot thin oil. Now that could be the pump itself or it could be that the oil is getting pissed off some where

What is your hot oil pressure at idle?

HaysKSFirefighter · Jul 17, 2011

Tom S said:
If it does not make 500psi or so or low pressure oil it is not going to fire. I was under the impression that the reservoir did not have to be under pressure only filled with oil for start up. The qoute above is a giant red flag for me. I think the pump is not making any pressure with hot thin oil. Now that could be the pump itself or it could be that the oil is getting pissed off some where

What is your hot oil pressure at idle?

Tom,

We haven't checked with a mechanical gauge yet, shouldn't it be like 10 at idle and 30 something at WOT?

We will put a gauge on it tomorrow to get the numbers

Tom S · Jul 17, 2011

My oil pressure is higher then that but my motor is pretty low miles.

HaysKSFirefighter · Jul 17, 2011

Ok, well I'll get a mechanical gauge on there tomorrow and see what the pressure looks like.

vanderchevy18 · Jul 17, 2011

I think he should also lose the rotella t5 and put some rotella t6 15w40 in since its like 110* here 24/7.

HaysKSFirefighter · Jul 17, 2011

vanderchevy18 said:
I think he should also lose the rotella t5 and put some rotella t6 15w40 in since its like 110* here 24/7.

Yeah it is worth a shot...it ran just fine last summer but then again last summer it wasn't this damn hot and I didn't have an oil hungry hpop.

Arisley · Jul 17, 2011

I am also betting LPOP. Heavier oil could disguise it.

Tom S · Jul 17, 2011

So a couple of you think that the truck will not start with just the HP oil reservoir full of oil?

G Racing · Jul 17, 2011

If the hpop reservoir is full of oil the truck should start. The lpop fills the reservoir and lubricates the engine. If the lpop is worn enough it could present a problem of picking up the thinner oil once it is hot but the hpop reservoir would be empty. So if the reservoir has been full each time with a hot no restart then the issue would lie within the hpop, injectors, or idm. Put a mechanical gauge on the reservoir and check your lpop to rule it out.

HaysKSFirefighter · Jul 17, 2011

The fact that the resi has oil is what is throwing us off. It will get a mechanical gauge on it today. We are also going to check the hpop drive gear bolt to see if it is loose or something since the issue started with its install.

What are some issues associated with a bad idm? I've never dealt with one thats bad before, well besides the whole stalling out when it rains issue people have.