BWilcox

Hi Guys,

I recently put a set of the AFR 180 Eliminator heads on my Son's Camaro.

The engine was running fine before the modification.

When starting the car, the engine starts and runs about 2 seconds and then shuts down like someone turned the Ignition Switch to off position.

During the short run the engine sounds good. No abnormal sounds.

Then, the engine just shut's off. Does not try to continue to run.

The timing light pulses until the engine is not turning.

I have not checked the Injector driver voltage.

When I attempt to keep the engine running by pressing the loud-pedal, the engine barely stays alive.

Here are some set-up details:

1. Base Timing = ~ 6° BTDC when cranking in Distributor Bypass Mode.

2. Fuel Pressure Before Cranking =~ 43 Lbs.

3. Fuel Pressure before stall = ~ 36 Lbs.

4. EPROM : Stock parameters.

5. All pre-start measurements (TunerPro V5) appear ok. No DTC.

When I attempt to keep the engine running by pressing the loud-pedal, the engine barely stays alive.

Any thoughts or past lessons learned for such a failure?

Any help is very much appreciated.

Best Regards,

Bruce

FireDemonSiC

This is going to sound really basic, but does the car have VATS? That almost sounds like how VATS shuts the injectors down.

It could also possibly be the fuel pump.

BWilcox

Thanks for the reply.

How would I tell if the vehicle has VATS?

I am the third owner and do not have the original keys.

Maybe I can locate a relay or special wiring somewhere?

Best Regards,

Bruce

FireDemonSiC

If it is a VATS vehicle the key should have a small black resistor in it.

BWilcox

Thanks.

I looked through various service manuals and could not find any infromation about VATS for an 88 IROC-Z camaro?

Was this installed as an option? If so, what is the RPO code? I have the build sheet for the car.

If this is not a VATS issue, what could cause such a failure?

Fuel Injectors ? Tomorrow, I will check to see if the Injector Drive is working.

Best Regards,

Bruce

FireDemonSiC

I'm not even sure if VATS was an option in 88, TBH. But It's famous for going out on these cars and that's how it prevents vehicle theft by killing the injector pulse a couple seconds after the car is started.

My next best guess would be the fuel pump, although since you installed a set of heads there is a chance a sensor is skewed somewhere. You said it barely stays running when pressing the pedal?

TKR 88 GTA

I know when I did my swap I had the same problem. Mine was a dumb mistake though lol I didn't have the brake booster line to Intake connected lol I thought I had ruined something just turned out to be a vacuum line though. Also when my VATS (my car is an 88 GTA so yes VATS in 88 was an option) acted up all mine did was click it didn't even crank mine had the security light on the dash was on when key turned on. With that fuel pressure it should start up and run mine ran on 28psi with my bad regulator had no get up go but stayed on.

PhoenixFirebird

iTrader: (2)

If I remember correctly, VATS debuted in 89. Also, he can keep the car running with some pedal. Sounds like a vac leak imo. Check all vac lines, aswell as gaskets. Mine was doing the same thing after an intake swap. Turns out I had passenger/driver side runner/lower intake gaskets mix matched. Just enough to cause a vac leak where the cold start injector would be.

Try running the car with MAF unplugged. If it idles a bit, that probably means a vac leak. No MAF forces the computer to use default low air tables. Also, spray ether/starting fluid all around the intake, runners, and plenum.

Good luck, hope this helps. Keep us posted.

BWilcox

Hi Guys,

Thank you for the help.

Tomorrow, I will continue to trouble-shoot the problem.

All of the vacuum ports that are associated with the plenum and throttle body will be capped. The FPR vacuum port will be connected.

If I have a vacuum leak, it should be isolated to the intake system.

How would I detect a baseplate to crankcase vacuum leak? Would I be able to detect a vacuum by looking at either the measuring the PCV ports (either valve cover)?

Best Regards,

Bruce

BWilcox

Hi Guys,

The car is now running ok.

I had a major vacuum leak on the passenger side. The rear gasket between the TPI Baseplate and the Intake Runner.

The large diameter gasket deformed when I bolted the system together. This resulted a fairly large unsealed area.

Very surprised the car even tried to run. The plenum vacuum was only 5 " HG @ 750 RPM. Very low for a mild cam.

Thanks for the help!

Best Regards,

Bruce

FireDemonSiC

Glad you got it figured out

In my experience, TPI motors are very sensitive to even small vacuum leaks.

When I installed my headers I forgot to plug the brake booster line back up. As soon as I drove the car the first 100 feet it stumbled and hesitated very badly with the slightest touch of the gas, idled horrible and tried to stall several times. Thought I had messed something up. Try to seafoam the engine through the booster line? Forget about it...

I also tried doing the PCV to intake manifold on driver valve cover with a straight breather in the passenger cover setup before. The engine would just randomly shut right off while idling at stop lights. It took me a couple days to realize the way the PCV system was designed THROUGH the MAF and I had created a vacuum leak by doing this.