98 T/AFuelProb

Hey fellas,


I have a rather nasty issue. So about a week ago I went to fire up the car and it started then proceeded to die right away. When I went to re-engage, the fuel pump kicked on for a split second (Not long enough to prime) Now it does this every time the key is on! I originally thought it was the pump itself, replaced that with a F98 RaceTronix, same issue. I also replaced the filter to no avail... I checked the relay which seemed fine. I replaced it with a different one and the pump now runs constantly! However there is still no fuel to the rail!. I have disconnected the filter and verified that there is pressure to the filter. Is there some sort of cutoff somewhere further in the line that would stop fuel from getting to the rail? Maybe a security issue, or a regulator further down the line?


I am stumped on this one....

98 T/AFuelProb

I don't know if this makes a difference, BUT the car just cranks.. If I add started fluid it starts and runs until the fluid is all consumed.

subeone

iTrader: (5)

Make sure the hose from the pump to the tophat is still connected

98 T/AFuelProb

I have pressure to the filter. That tells me it's all hooked up in the tank.

subeone

iTrader: (5)

what about immediately post filter ? dirty/clogged filter could be a possibility. another possibility is a ripped/collapsed fuel line further down the line.

98 T/AFuelProb

Well, update time. I now have 60 PSI to the Schrader valve, spark, and compression but no running engine! I should have checked this first, but I'm getting P0601 trouble code... It seems I may have a dead PCM. Not cool on a 98 T/A! So I'm thinking that the PCM is not letting the injectors open? I hooked a test light to them and the light stays constant. There is no pulsating going on.


Thoughts? You think I narrowed it down to the root cause?

subeone

iTrader: (5)

leave the noid light hooked up to an injector and crank. if it pulses then the pcm is fine.

bigsticksupra

iTrader: (3)

how long does that 60psi hold after the car is off?

98 T/AFuelProb

I haven't checked the PSI to know 100% for sure, but I can tell you it held to like 35 when I removed it after about an hour or so of messing with different stuff.

JoeNova

Check to make sure injectors are pulsing during cranking.

I have this same problem on occasion with one of my LS swapped cars. Pump primes for a split second and shuts off. Car won't start. Its a bad ground for the ECU every single time.

98 T/AFuelProb

So Joe, how exactly do you fix your problem when that occurs? Does yours throw a code for the PCM when that happens? Where is the ground wire that gets out of contact?

JoeNova

I don't usually bother checking the codes.

I originally had an 06 ECU that I fried. The ground wires for the O2 sensors in 06 are pinned into the ECU, so I had all of the ECU/O2 grounds soldered together with a quick connect terminal on the end that is hooked to a large ground wire thats bolted to the underside of my dash. The ECU lost ground while flashing and quit working. It wouldn't prime the fuel pumps at all after this happened.

I still had the ground issue after swapping to a 2000 ECU. First got it hooked up, pumps would prime for a split second and stop. I noticed that the quick connect for the ground was unhooked, so I fixed the ground and it went away. A couple of times I've accidently hit the ground wire and knocked it loose and my pumps barely prime and the car doesn't start. Everytime I just fixed the ground wire and it started fine.

98 T/AFuelProb

Interesting. I'm am going to have to check the pins on the plugs and see if I can see anything that's out of whack.

bigsticksupra

iTrader: (3)

might want to check with the fuel pressure gauge on the shrader valve off the fuel rail. i had a similar problem where fuel pressure would bleed off quickly which caused my car to have extended cranking and start times

98 T/AFuelProb

Re reading that I guess I wasn't clear. I did check the pressure at the schrader which gave me the 60ish psi. I didn't bother to check how long that pressure stayed consistent, but I can tell you I had about 35ish psi when I bled it to release the gauge.

98 T/AFuelProb

I have ripped the ECM/PCM out and am looking to get it replaced. To my dismay, this part # 77-8212F (16238212) basically does not exist any longer... This is very frustrating.. Does any one know where to get this thing? Or can recommend a competent shop that refurbishes these?

JoeNova

98 ECU?

Re-pin the connector and convert to a 99+. Very common upgrade.

98 T/AFuelProb

I hear that is a common upgrade, but I wouldn't even know where to start. My fear is I'd do more harm than good. lol I have read that you have to change the internal gas reading mechanism and maybe parts of the cluster?