'83 CFI, 102K miles. Okay, car started running rough off and on last week and progressively got worse. Car will run great and then suddenly want to stall and barely run.

When this happens the front injector goes dead and car is only running, (barely) on the back TB. I'm thinking that this must be an electrical issue. If I let it cool down, it'll start right up and the front TB delivers a nice conical spray pattern. A few minutes later it goes dead again. Perhaps a solenoid went bad. Is there a solenoid in the injector itself? Or could there be a failure in the regulator? I did notice that the front TB has a slight leak above the injector a couple of days ago.


Thoughts?

 

most likely the cause is a bad connection:check the injector fuses and the plug on top of the non-firing injector the prongs can spread apart and not make good connection to the pins .A faulty ECM or injector are also possible but far less likely than a bad connection.The injectors have battery voltage applied with ignition on and the ECM grounds the injectors to "fire"them.

 

Wouldn't a bad fuse knock out both TBs? Or do they have separate fuses?

 

they use their own 3 amp fuse.

 

Okay. All 3 amp fuses are good. I pulled out the ECM - and even though I really don't know what the hell I'm looking for - everything is connected and nothing looks fried. As far as I can tell, it seems all the electrical connections are good.

So, I HAVE A THEORY. Let me run it by you guys. As I said, I just noticed that the front TB has a leak. The leak is on top, above the injector, right at the electrical plug. Is it possible that as gas pools up there by the plug and pins, that it eventually shorts and kills power to the TB? That might explain why it takes a while for it to shut off and then restarts normally after it's been sitting.

Does that make any sense at all?

 

gas does not conduct electricity,so the pooled gas would not cause a short but the gas could insulate an iffy connection and cause the trouble.If you can get the car to act up and you have a 12v test light or voltmeter handy,check that steady power is present at the non-firing injector(or wiggle or twist the injector plug a little to see if it resumes operation)

 

Charlie - if you have a leak you should rebuild those TB's and eliminate it as a cause. It should take you a few hours and you may even want to have a injector cleaning service do a cleaning on those injectors. The car has 100K - it should be done anyway. I still think that the problem is electrical though.

 

I agree on both counts. It must be electrical, how else can it go from running great to not running at all, the way it does? A couple of my car buddies are coming over tomorrow to hang out in the garage. Maybe we can all put our heads together and track down this gremlin.

 

BTW - if it is leaking out the top it is probably a bad O ring.

 

Hey Charlie - if you give up on her I will take it off your hands!

 

Hey, don't tempt me!