I purchased my son an 88 GTA Notchback a few weeks ago for 1800.00.

It has LT1, TPI 350 engine with 86K on it.

It had sat for over a year in the previous owners (PO) driveway. His daughter wanted a truck instead.

I was able to drive it home and it would start and run but I knew the timing was off, as it would run rough. We had to put a new battery in it and I was afraid it would burn out the old fuel pump. Sure enough, it did.

We replaced the pump and filter. Fuel pump is working as we hear spin up before we attempt to start the car. I depressed the valve on the fuel rail when we attempt to start it and it shoots to the bottom of the open hood, so I have enough pressure.

The engine will turn and it will fire only when I use starting fluid in the throttle body. Verified coil is working.

The PO said he had tried to modify the chip settings before but had not completed the programming.

I'm baffled that changing the pump and filter have affected the engine this much.

Any ideas will be appreciated.

Jim Berry.

 

Security light flashing?

Sounds like a VAT issue or the injectors are junk flooding the engine.

Get a noid lite and see if the injectors are pulsing

 

No VATS in 88.

Which is it? LT1 or TPI?

Ohm the injectors and don't forget the cold start injector. Of course this is assuming you have TPI.
Injectors ~ 16ohms
Cold start ~ 4ohms

 

It could be a bad fuel pressure regulator too. But if you know you are getting spark, then I would probably suspect the injector too.

 

replace your ignition module, a bad one will prevent the injectors from working

 

GTA's did get VATS in 1988, the other models got it in 1989....

 

Rented a NOID light kit from O'Reilys'. Got fuel, got spark, as it will run briefly on starting fluid. Pulled each injector line from the injectors and tried the NOID light.

No lighting happened. Checked all fuses under dash and all are good.

I don't think the car has VATS, as I don't see the dash light on the initial start, but the car key has the VATS tab on it.

What next?

Jim Berry

 

VATS was standard on the 1988 GTA, but there was several (thousand) early model 1988 GTAs that apparently didn't get VATS before this. If you have the resistor key, I would have some assumption you have VATS as that is part of the system. If you see no yellow Security lamp, the bulb could be burned out or the VATS module or circuit could have an issue.

The system is supposed to disable the fuel injectors from firing as well as not enable the starter relay. However, the system, due to the design, could allow the starter to enable while the injectors may not be enabled if a certain fault occurred with the circuitry.

As you don't have injector pulses, it's clear that is the issue. Do you have +12VDC, constant on, with the key on? You should see +12VDC with the key ON if the fuses are OK and the ignition circuit is OK. There are two fuses; one fuse per bank.

The ECM fires the fuel injectors, by grounding them, if it receives input pulses from the distributor module.

 

Double checked the INJ/1 and INJ/2 fuses. Both are okay. Purchased a new ignition module from Oreillys and will install it within the hour. Can't figure out why all this is connected to replacing the fuel pump. I will hard shine a flashlight into the front of the dash to and see if there is a VATS dash light. I have VATS on my 91 Firebird, so I am aware of what to look for on the dash. Additionally, the computer isn't throwing any codes. All we get is 1-12, 1-12, 1-12. Which is normal ops?.

Jim Berry.

 

Code 12 means no reference pulses to the ECM. It's normal to see this with the engine off, but ignition on. However, that does not necessarily mean no errors or faults. Code 12 is a diagnostic code, after all, and does not mean "all clear".

As you are not seeing the fuel injectors firing, you have narrowed down the issue. We still need to know if you have +12VDC at the injectors with the key On. The fault is either going to be on the +12VDC side, which could be a circuit/wiring issue, or it could be on the ground side which the ECM controls after it receives reference pulses from the distributor.

Since you only replaced the fuel pump, and you have fuel pressure, I would assume this is a coincidence unless I'm missing something. Things do break, without warning, at times. You could remove the fuel pump, but you still should have ECM firing the injectors as the ECM doesn't know anything about the fuel pump and can only command it to run, not follow-up on it.

 

The car started!!

Thanks for all of the help to date. Great options on the troubleshooting side. John 89 hit it on the head.

Ignition Module. Only, didn't need to repace it.

As I disconnected the coil lead to the distributor cap and set it aside, I reached around the distributor to see how many screws I had to release and also to release the two pigtails.

One of the pigtails had fallen off of the ignition module nodes. The clips that are on the pigtail (weatherpacks) were missing and the pigtail had fallen off when I rotated the distributor attempting to set the timing.

We were able to start the car and set the timing @ 6 BTDC.

The car settled right down and seemed to idle just fine.

Now for the next problem: Altenator.

I will not address it here as the initial problem has been solved by the input of the teams here at Thirdgen.org. That is why I visit here, try to help here, and visit the merchants that are on the web sidelines.

Again, many thanks for everyones input.

Jim Berry