Okay fellas (and ladies), I was having problems with my engine idling erratically. I took my car into a mechanic and after 3 weeks the best suggestion he could muster was to change the spark plugs, wires, distributor, distributor cap, and rotor. I've replaced everything except for the distributor so far and the engine isn't any better. Somebody on here replied to a post about this same problem saying that the injectors should be checked. I checked the resistance in all eight injectors (with the engine still warm) to find that #6 and #7 are way different than the others. The average resistance of the rest is 19 Ohms. #6 is 13.4 Ohms and #7 is 8.9 Ohms. Are these two injectors the source of my problems? If so, can I replace only these two injectors? I really don't have the money to replace all eight right now. Thanks for the help!

 

How eratic is it?
Mine would float around sometimes from 800 to 550,then I happened to change my thermostat from a 160 to a 180 and since then it's steady at 550 until the fan kicks on...

 

You should change those injectors. If you can get just two used you'd be fine. If you go to the dealership to get 2 you'd be better off getting all 8 aftermarket.
That low of a resistance will cause a sputter once the injector warms up. It creates an open in the circuit.

 

What do you mean creates an open? I'm an aircraft mechanic, but I really don't know much about electronics.

 

OK. Forgive my ignorance and please no flames!! But how would low resistance cause an open in the circuit? I am not disputing that it could or will cause a problem, just curious what exactly that problem might be.

What kind of resistance value should we be looking for? I would like to test mine also.

 

Sorry it's not an open. It's developing or is a short in the circuit.

Resistance should be ~16 ohms.

 

Run an injector test on all the injectors to see how much they are putting out and also check for any vacuum leaks. Leaks can be a big problem at idle. Does it run fine once you get going?

 

Okay, so I replaced those two injectors, but my problem still remains. Damn! When I took my car into my mechanic to have him troubleshoot it, he suggested I change the distributor. Maybe I should try that. BTW, how do I check for vacuum leaks? That's what I thought it was fromt the start anyway, but what the hell do I know?

 

id take a can of wd40 and spray it in places where there could be a leak and if the rpms increase after u have sprayed a certain spot then its a possiblity thats where the vacuum leak is at. thats how i found 2 leaks one was from an egr block off plate. and the other was in the runner to manifold location so i fixed that and it ran perfect after that.

 

Thanks fellas, I think I've finally got my problem licked. What I did was replace injector 6 and 7. My car still ran poorly after that but I think that was due in part to two reasons: 1) I forgot to clip the throttle cable back into the bracket that is attached to the plenum (that also caused me not to get out of 1st gear), 2) one of my PCV hoses was leaking. My car doesn't idle perfectly now, but it's way better than it was. My mechanic says that it's because I have a lot of blow by. Is that bs? I only have 80,000 miles on my Formula. What do you guys think?