1988 Trans Am GTA.

Pulled out the original distributor with external coil. Replaced with HEI, ignition fires, Does start with added fuel, but does not get any Injection Pulse.

Does have Knock Sensor, with ESC. Do have another HEI with vacuum advance and another 4 wire connector, but do not have a place for it.

350 tpi, not stock engine, 10054727. T-5 tranny.

Any advice?? Ideas??

Thanks in advance

 

did you upgrade the computer as well.. I believe the ECM is what grounds the injectors after the distributor pick up coil picks up the signal that the engine is turning, sending the signal back to the ECM, through I believe the IGN Module... ... you do have power at the injectors?

 

Pretty sure you need a ecm controlled HEI for a easy swap, like my 85 one. No clue how'd you'd made old style HEI work with it. Mine has the 7pin control module and no weights or vaccum. Not sure why you'd want a large style HEI vs your small dist external coil, but i dont know too much bout the pro/cons of the smalls. I made mine external coil after a few coils overheating.

 

I did not touch the ECM. I have been having an issue with the ignition breaking up at about 3500 rpms. Where the it would not rev past 4500. This was with the original small dizzy external coil.

This HEI was just laying around and i thought id give it a shot. I cannot find anymore information on the "camshaft Sensor" so to speak.

I do have Power at the injectors, i gave one ground just to give it some fuel to test.

What im trying to figure out is what the computer needs to give it fuel pulse, and how do i get it??

 

In our cars the task of the camshaft sensor is performed by the pick up coil inside the distributor... if it's breaking up like that, have you checked your TPS? MAF sensor?

 

I have swap the MAF with one of my friends... no luck. He had a TPS sensor laying around i have tried that as well...Still no luck.

Some say that 350 with 305 ecm wont work, other say ppl have done it with no problems other then running a little lean.
My issue is that it drops dead at 3500 almost hitting your face on the steering wheel dead. Sounds and looks embarrassing.

Because of the manual transmission, i cannot find another 350 chip to test. Hypertech and jet performance ships say they cannot help me. I do not honestly think i am having an ecm issue. Therefore i am trying the HEI.

Parts i have tried so far...
26lb injectors, BBK fuel pressure regulator, fuel pump and sending unit, full 3" exhaust cat and edelbrock muffler, TPS, MAF, Distributor, coil, Knock Sensor, ESC, O2 sensor, plugs wires, fuel air filter, intake gaskets, EGR.

I guess the HEI is not going to work for me, anymore help or ideas??

 

Also i cannot get the TPS to calibrate to .054. It will only go to .048 think that can have have anything to do with it??

 

does this only happen when you're in drive or does it also happen when in park...

 

Manual Transmission. Happens all the time.

 

Could this be limp mode?? As if the ECM is bad and its running solely on the Memcal??

Im not sure as the car does accelerate hard at lower rpms... although it does not like to cruise at lower speeds so well lol.

 

Woudn't be the 305 chip, mine ran with the 85 ecm and 305 chip b4 i swaped too 86+ ecm an 350 chip. BUT I had bought a 89 chip witch is VATS and needed a vats bypass off ebay. What year is your chip, if your adding fuel?

"Does start with added fuel, but does not get any Injection Pulse."

 

Yes it does start with added fuel, just not getting injection pulse... now that was the HEI distributor, i decided to scrap that idea and go back to the smaller dizzy with external coil...

The whole reason i decided to try the HEI, was because the car is having a loss of power and will not accelerate above 4500.

 

When my car wouldnt pull past 4k it was due to a tiny hole in the vacuum line to the fuel pressure regulator.

 

Tried running it without vacuum, (45lbs) no change.