So after about 3 weeks, we finally got the remanufactured engine installed into the 1998 Camaro. We can get it to start for a quick 5 seconds..and then it'll seemingly choke and die off. Afterwards then it'll crank a bit before it starts again. We can't locate the problem exactly..It seems as if it's not getting fuel somehow.
Also, we turned the key to just run to see if we could hear the fuel pump, we're fairly certain it isn't that because that seemed to run just fine with no problems. So we're thinking it's maybe something with the fuel filter or one of the sensors?

 

have to tested the fuel pressure?

 

We have yet to test the fuel pressure - we don't have a gauge for it.

 

Sounds like the VATS system or the oil pressure sender to me. VATS will disable the fuel pump if it does not recieve a good signal from the key, and the PCM will not run the fuel pump until it reads oil pressure. Your engine will start and run for a second or 5 just off the fuel pressure that is built up as the fuel pump primes.

Massey

 

Yeah we do think it's definitely something electrical, what if it did turn out to be the VATs disabling it? Would we have to get a new specific passkey to get it to start or what? Like everything worked fine prior to the new engine. (Besides the lower bearings being shot, it would still at least run)
But, when I turn the key to 'Run' the security light just lights up with all the other lights and indicators as normal, it doesn't flash, and just shuts off a second or two after. So we don't think it's that either, though we do think it's related to the PCM in some way.

 

The PCM is most likely not turning on the fuel pump relay. Try jumping the relay as you start the engine and see if it will stay running.

Massey

 

The fuel pump relay works fine, we'd already tested it. We're not more or less focussing on VATs and trying to figure out how to bypass it completely. Any tips on that?

 

I am more of the fix whats wrong over the bypass and jurry rig type of repair.

I am not questioning the ability of the FP relay to function but does the PCM activate the FP relay when you start cranking the engine. If so then look at the pump and or FPR if it does not then I would look at the Activation circuit for the fuel system. This involves the Oil pressure sender, PCM, FP Relay, BCM/VATS and the wiring involved with the system. Make sure to check all connections, and make sure there is nothing broken between connection. Search your fav search engine for schematics for the Camaro/Firebird, there is a set (not on shbox) that is for the 2000 that will give the correct wiring for your car. It is about a 128 meg PDF file.

Massey

 

When the VATS is activated, it disables both the fuel pump and the starter. Since the engine cranks over with the key, and you can hear the pump priming, and the security light isn't on afterward, it can't be the VATS. What activates the pump relay after the engine starts running is an ignition signal to the computer, not oil pressure. Unless GM did away with how the system worked on the 3rd gens, the oil pressure switch doesn't have anything to do with making the fuel pump run. (see the TSB below) Yes, there is a parallel circuit running through the oil pressure switch, but that's to keep the fuel pump running should the pump relay fail. It's a fail-safe back-up circuit, not a safety feature that won't let the engine run without oil pressure as some believe it to be. Fords work that way, GM's don't.
So with that, are you getting a check engine light at all? It appears as though you may not be getting a signal from point A to point B to keep the fuel pump running.

UPDATED BY TSB 893206E, DATED OCTOBER 90
When the key is first turned ON, without the engine running, the control module will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the control module will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the control module turns the relay ON, which powers the fuel pump. The control module continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi).

RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION
A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold.
An inoperative fuel pump would cause a no start condition.
A fuel pump which does not provide enough pressure can result in poor performance.

 

Alright well we scanned it for codes and it came up with a low TPS voltage reading I believe. How should I go about fixing that, besides buying a whole new one if that'd even help?