Well my car is an 85 iroc-z with a 305 tpi. Today the car started to run rough after it sat running awhile. The whole car would shake and it smelled of gas. So i got it home and i searched and i read stuff about bad injectors causing that. I put an ohm meter on them and the highest reading i got was two ohms. Then after i let it sit for a while and started it and it was normal but when it got warm and it started running rough again. The exhaust sounds alot different than it used to. Does this make sense to anyone? Any help is appreciated.

 

bump

 

ttt

 

What is the OHM readings of all the injectors hot? What are they cold?


How long has it been since you did a tune up?

What is fuel pressure reading? Is your car hard to start in the mornings?

 

Ok I got the numbers from my injectors.

Cold
1. 16.5 5. 16.2
2. 16.5 6. 16.4
3. 16.5 7. 16.3
4. 16.4 8. 16.4

Hot
1. 17.1 5. 16.8
2. 17.2 6. 17.0
3. 17.1 7. 16.9
4. 17.1 8. 17.1

Fuel pressure was 42 psi off and 38 psi idling. After i shut the car off and after 20 min i had lost 7 psi.

The last tune up I did was in April. The car is not hard to start in the morning but sometimes it does take a few extra cranks than others.

 

bump

 

How does your exhaust sound different?
Could you have broken your catalytic converter?

Otherwise a bad O2 sensor will cause bad running only when the engine warms up enought to go into closed loop operation.
I think your factory calibration is 104*F to go into closed loop, so if you run good up to that temperature then I'd suspect the O2 isn't working right.

 

I doubt it's anything fuel related then. Everthing there is within spec and completely normal.

I now suspect a module or coil.

I know that this picture is from a V6 distributor, but if you find the same spots on your V8's distributor, the readings should be the same deal (sorry I dont have a picture of a V8's for this)

 

when testing this does it make a difference if my car has an in cap coil?

 

I would still suspect a leaking injector. Just because the resistance readings are good, this doesn't mean the injectors are definitely good and not leaking. It only means the injector coils are not shorted or open. I had this exact problem with my 89Z, and a new set of Ford Motorsport 19# injectors have the car running like new again.

 

i think its my coil... the pick up coil tested fine but when i checked the coil on step 2 i got a 1 on the low scale.

 

To answer your question, no it shouldnt matter whether it's in cap or not. as long as you test the same grounds and such

Sounds like you may have found your culprit though. Good job

 

yea i put in a new coil and it made no difference. so do you think the ignition module has gone bad?

 

Well i replace the ignition module cause i like to waste my money and there was no difference. So do you think a fouled plug may cause this? Im outta ideas.

 

did you test the new pieces? It wouldnt be the first time there was a defective part... brand new.

 

so you think i got a bad coil from the store?

 

so i replaced the coil under warranty and i changed the plugs with no real difference. when i changed the plugs i noticed that only the #1 was wet with fuel.

 

If you take off the fuel injectors, leaving them on the fuel rail, and have someone turn the key, do all of the injectors spray evenly? (Or a more time consuming, but probably safer way to do it is pull one at a time).... just make sure you aim AWAY from the distributor and anything relating to the ignition system.

 

tonight i pulled four off the right side and of what i could see the sprayed evenly. I took them off and all of the caps were cracked and one of them had a piece missing. could this cause my problem?

 

would it be possible to take a picture?

 

They may spray fine when cold, but not when hot. That's why your car only idles poor when hot. Therefore the test you are peforming may not be completely valid. Since you have the plenem all disassembled, I would suggest that you go ahead and spend $200 and get a set of Ford Motorsport 19# injectors from Summit. I went through the exact same exersize with the exact same symptoms and a set of injectors cured the problem. My original injectors had been in the car for 205,000 miles and were getting progressively worse over time. In addition to a much better hot idle, throttle response improved dramatically after installation of the new injectors.

 

sounds like my problem but ill wait till this winter to get some cause i dont need to drive this car now. so where is a good place to get these at a decent price?

 

Summit has the lowest price that I could find. You have to call and ask for them since they aren't listed in the catalog.

 

you may need to run some more ground wires. My friend has an issue with his fox body that it has a hard time starting when it's hot, he ran more ground wires and it fixed that problem.