Injectors not firing properly.
Hi All. Odd problem and I'm stuck. 88 CSX-T. Stock electronics. Been off the road for more than a couple decades now. But it HAS run in the past few years. As recently as last summer for sure. I decided it's time to finish it and bring it to SDAC this year. Or at least drive it as finished as I can get it. But there seems to be a problem with the injector circuit.
When I crank, I get good fuel pressure and spark, but the injectors don't fire. But if I spray in a bit of starting fluid or gas, it kicks of for a second or two. I discovered it by accident, but if I disconnect injectors 1 and 3, it will start and run roughly on cylinders 2 and 4. If I connect 1 and 3, no start. Disconnect 2 and 4, starts and runs roughly.
So far, I've changed the fuel (it was old), the injectors, and even the injector harness and I'm getting the same thing. Fuel pressure is good. Changed from the Mopar Performance computer back to the stock one, too.
Any one else had this one before?
I'd really like to take this to Detroit, but I may have to start prepping the Rampage if I can't figure this out soon!
Thanks!
Re: Injectors not firing properly.
I'd start by ohming out the injectors. The cylinders are batched fired 1&2 and 3&4. Seems like maybe something is shorting out if you're disconnecting one injector from each bank then it starts and runs on those 2 cylinders. Many people have had lots of issues with fuel systems esp. after storing for long periods of time. Do you have any known good injectors you could swap out? I bought a low mile car recently and the injectors, tank, fuel pump assembly all failed after car was sitting for 4.5 years. I can only imagine what the spray pattern must be like on something sitting for a couple decades.
Since the fuel rail is so easy to remove on your 88 T1, I would take it out of the car and examine it carefully. I've tested fuel rails where I hooked up schrader valve to another working fuel car (fuel rail) and plugged the inlet and outlet of the fuel rail and manually applied 12v source to check flow pattern and to see if they're even firing. I usually do this before putting injectors back into service after they've been sitting in a box for a while. They can leak externally too. If you find that is the case, they're not serviceable.
Re: Injectors not firing properly.
I have brand new injectors in it. When the old ones wouldn't fire, I had a feeling they were gummed up from bad gas. New injectors are at 2.7 ohms, old ones are all 3.0 - 3.4. Going to check the injector harness to ground and SMEC later. I just can't help feel this is something small causing a huge issue!