jugheads88gta

i am working on a 89 gta 350 tpi and i cant get it running first i had a fuel issue it turned out to be the fuel pressure reg i have spark also.the car will start when i spray gas in the intake mani but wont stay on it sounds like it want to start but just doesnt i have the oil pressure switch plugged in at the one by the filter and the one up top is just blocked off.therwe is a single wire thats has no were to go on the harness by the break booster and motor could that be the problem or maybe just out of timing alittle bit what? not getting any codes either.

thewizard

iTrader: (43)

If it's a spaded connector, that went to the oil pressure sender which supplys the gauge with a signal. The one by the filter sends info to the PCM. Without looking at a scematic I'm not sure if the way you have it wired would correlate with the no start issue.

A lot of the no start issues on these projects relate the the VATS. Did this particular car have that?

jugheads88gta

Yes it has vatts but if the vatts was locks up wouldn't the sec light stay on? And while cracking the gauge reads 30-50 psi

jugheads88gta

Could it be timing?

thewizard

iTrader: (43)

Yes, it could easily be timing. You have access to a timing light and fuel pressure gauge?

The PCM could be pissed it's not seeing oil pressure. Have you tried plugging that connector in as opposed to sending the signal to the gauge?

jugheads88gta

yes i have both. and the plug at the to of the motor has no were to plug in and the one at the bottom by the oil filter is plugged in already.

KrisW

iTrader: (5)

There's more than one thing going on with fuel pumps and maintaining pressure.

Your fuel pump relay gets turned on by the ECM to prime the system then it shuts off. Once you are cranking and you have oil pressure, the oil pressure sender has a switch in it that latches the fuel pump circuit and provides power to the fuel pump. There is a 20 amp fuse next to your battery in a little stand alone fuse holder. That fuse is for your fuel pump.

If you do have plenty of fuel pressure then check INJ 1 and INJ 2 fuses. Tell us how the above works out and we'll go to the next step.

KrisW

iTrader: (5)

If the car runs when you spray gas into it, then the ignition is good enough to start. Don't mess with it yet.

You might want to use a noid light and check that the injectors are actually pulsing when you crank. You can get them cheap at an auto parts store or make one from an 1157 bulb and some soldered on leads. Maybe you even have a nicer Voltmeter that has injector pulse width readings ability.

vetteoz

iTrader: (13)

Nope

jugheads88gta

I checked alkaline the fuses thy are all fine this morning I went out turnedvthe crank by hand and put it at 0 tdc and checked where the dist rotor was it was facing toward the front of the motor instead of at the #1 spark plug so I moved it to face the #1.

jugheads88gta

I am going to pick up a noid light today what should and should not happen when I plug in the noid light to the injector wire?

KrisW

iTrader: (5)

it should flash rapidly like the injector is getting pulsed

thewizard

iTrader: (43)

Thanks for confirming that; I looked at a schematic this morning, and was mistaken in my recollection.

jugheads88gta

alright so i put the noid light to it and got nothing from the injector wires

KrisW

iTrader: (5)

Well, all the fuel pressure in the world will not help you if the injectors are not pulsing.

Someone earlier mentioned the VATS system. It disables the injector pulse when activated. I think maybe you do have a VATS problem. You can search the forums here and there are threads about how to disable it and bypass it to test your system.

The other possibilities are all ECM related. Its not common for ECMs to just die, so I suspect you really are dealing with a VATS issue.

KrisW

iTrader: (5)

When was the last time that it ran properly? What was the last thing that happened when it stopped running?

vetteoz

iTrader: (13)

Key on ;do you have 12V at the injectors?

John 89 Formula

A bad ignition module or a bad pick up coil will cause the injectors to not pulse

chevyredneck8

iTrader: (4)

Their is two oil pressure sensors one behind the tpi intake with a singel wire and one above the oil filter two wire Hayes for firebirds says one is oil pressure switch (gauge) and the other is oil pressure switch (Fuel pump). the 1987 schematic doesn't show it being ecm connected, but my 1990 gm camaro manuel shows it being connected to the ecm if im viewing it correctly.

Id try hooking up the other sensor and trying that before trouble shooting an ecm

Apeiron

The OPSU isn't ECM connected in any year.