New Conversion will not start (1 Viewer)

[fussy_cruiser]

Little background:

305 TPI swap, stock harness out of the camero, MT, external fuel pump.

Have spark, fuel pressure and FI noids flash when trying to start. Next, I am going to remove the injectors and clean (should have done in the first place).

Anything, I am missing? Dist was 180 out, fixed, car will run with starter fluid injected into unused vacuum port.

Thanks,

 

[iaintscared1969]

Stock harness? After market? Got nuetral safety switch. Fuel pressure high enough for the fuel pressure cut off switch.

 

[Downey]

If you are satisfied that you have fuel and spark, then perhaps you don't have the oil pressure sensor hooked up??? If this is the case the ECU believes there is no oil pressure, consequently won't let the engine run. Just a guess!!!!!

 

[inkpot]

Howdy! If it runs on starter fliud, then you have a fuel supply problem. As noted, oil pressure sensor/solinoid will shut off fuel supply. John

 

[fussy_cruiser]

I have plenty of fuel pressure 45PSI @ the fuel rail.

Spark is good too, like 30mm on the tester.

I was just wondering if there is anything that will cause to computer to not fire the injectors. But I hooked the noid light to the fuel injector harness and I get a flashing light.

I look thru thirdgen.org, but those guys are all talking about stock camaros and I have 90% of the emissions off the vehicle and it has never started.

Thanks,
Kirk

 

[Senor Aguas]

Any chance its the VATS? From a quick search, it looks like it wouldn't crank or have fuel pressure if the VATS is the problem, but it still might be worth looking into.

Vehicle Anti-Theft System (VATS)

 

[cruiserbrett]

vats is a starter interlock, so it wouldnt crank if it were the issue. does the fuel pump run once you build oil pressure? It should run for two seconds once the key is turned to the on position, but stop after that, until you build oil pressure. you can by pass the fuel pump relay by supplying 12v to the fuel pump prime connector that hangs down from the fuel pump relay.

Next question: are the injectors stock? there are high and low impedance and apparently this can be an issue with the GM ecm's. also beware that if they are larger than stock you should reprogram the PROM, since it has a value for the flow rate of the injectors, so it can calculate the proper amount of time to hold each injector open.

Also, dont try to start the engine with the throttle open past a certain point, I think its around 20% open; the ECM will not fire the injectors if the throttle is past a certain point to prevent high rev starts.

 

[UNO_RACING]

Not sure if this could be it, but do you have a vented gas cap? If you're using a sealed gas cap the fuel line could have built up too much back pressure (as it was priming) creating a problem with fuel flow.

Just an educated guess on my part. Please let us know the outcome.

 

[lone gunman]

if it ends up being VATS check these guys out for a way around it! Baker Electronix

 

[fussy_cruiser]

No VATS, this is off an '85.

Thanks for all the help.

Lesson learned, when you have the motor out, clean out the injectors.

Pulled the injectors and let them soak overnight in FI cleaner, then used a battery and some alligator clips to actuate them, then blew them out with compressed air.

Put 'em back in and it fired right up. :whew

Guess they were a little tarnished from sitting with old fuel in the rail since about 1993!

Now to tune this beast up and get it out of the garage.

 

[fussy_cruiser]

Also, dont try to start the engine with the throttle open past a certain point, I think its around 20% open; the ECM will not fire the injectors if the throttle is past a certain point to prevent high rev starts.

I chased this one around for a while.

I now know more about the TPI system and it operating parameters than I ever wanted to know.