Coil pack

[garrett]

What are some of the syptoms of a marginal 84 coil pack? Have already ruled out ignition control module on passenger relay bracket, plugs and wires. Car idles fine, drives normal until about 6lbs of boost, and then sputters. The car runs rich and often the O2 numbers start climbing to about 835 while sitting at a red light. No idiot lights on except for the coolant temp light. I shorted out the temp sensor about 3 weeks ago. Any ideas?

 

[Jerryl]

Could be coil pack.
Did you put an Ohm meter on it?
What plug gap are you at?
Where are you taking your boost signal from?
What MAF and condition are you running?

 

[garrett]

An ohm meter doesn't tell you much, since I can't test it under load.
As far as the plug gap, I haven't changed it and the condition is getting worse. I don't think a plug being a little off on the gap would make it run like it's running. I'm running an 84 maf. the numbers are at 5 at idle and go up corresponding with throttle. I have two boost gauges in the car, I know what my boost is.

 

[Jerryl]

An ohm meter doesn't tell you much, since I can't test it under load.
As far as the plug gap, I haven't changed it and the condition is getting worse. I don't think a plug being a little off on the gap would make it run like it's running. I'm running an 84 maf. the numbers are at 5 at idle and go up corresponding with throttle. I have two boost gauges in the car, I know what my boost is.

What I posted were some of the things (ideas) I would verify from the start. Did not mean to insult your intelligence.

while an ohm meter does not "test under load", it is a good start.
The Caspers load tester has not always been fool proof either.

Bet your verified all your grounds and voltage, including plug wires as well.

 

[garrett]

I replaced the coil pack, and that helped a bit. The O2 numbers are not as rich, especially when sitting at a light. The car still sputters and jumps around. I'm going to try to replace the MAF. I have an old 85 MAF, I just don't know the condition of it. I would like to try my 87 MAF since I know it works properly. My Turbotweak chip is set up for the 84 MAF on a 87 ECM. I don't know if I can throw an 87 Maf in there without sending the chip back to Eric?

 

[6SENSE]

...ignition control module on passenger relay bracket...

What is this? The coilpack sits on top of the module.
Could be the module.

Could be a plug wire. How did you test the wires? A visual test doesnt always tell you everything. I have had wires in the past that looked perfect on the outside but when I touched them they were crunchy on the inside like they were burned up under the insulation. Could check the resistance on each with ohm meter. My car would idle fine and drive okay until I tried to get into it. Car would backfire when I got on it.
Ohming out the coilpack across the towers is always the first thing you do when it is suspect. Should be 11k-13k. If there is a problem with the coil you will usually see it here. The module is another story.
The Temp idiot light is connected to the temp switch. Is that what you shorted out? Just want to verify because you mentioned the temp sensor which if that is bad WILL give you problems for sure. Do your temp readings read correctly with a scantool?
Also check your voltage. Could be an alternator issue. Check both at idle and under load.
One badly gapped plug wont do it. If all the plugs arent gapped correctly then might. I know a guy who changed his plugs and obviously didnt know what he was doing. He had them all gapped at over 60+ if I recall. Car did not like it at all.
What are your BLM #s?
Any VAC leaks or exhaust leaks?
Any ECM malf codes?
What condition is the O2 sensor? Do O2 cross counts move okay?
Cat or no Cat? What condition?
IAC #s?
Verify that TB blade is opening all the way.
Swapping in a known good MAF sensor wouldnt hurt to help the process of elimination. Try the tap test with scew driver or something and see if the car stumbles.
Make sure TPS is #s look okay and are not jumping around while driving, etc.

 

[garrett]

The car idles for a little bit, then stumbles and recovers every three seconds or so. Under boost, it stumbles at 5lbs and up. runs kind of rich according to the O2 numbers on the scanmaster. I have replace the spark control module on the relay bracket, coil pack/module, replace or tested all spark plug wires with ohm meter, and took out al plugs-they are all the proper color. The problem is getting worse over the last two weeks. No codes being displayed. No cat, tps set properly, Maf numbers start at 9 and go up corresponding with throttle. I fixed coolant sensor, O2 numbers jump all around from 050 to 850. O2 sensor is about 18 months old.

 

[6SENSE]

MAF #s idle at 9? I think that is a bit high. Shoulg be closer to 5~. Try tapping the MAF with the end of a screw driver and see if idle changes in anyway.
Might be an issue with ECM?
Is this a 87 ECM or the stock 84? What chip? Stock injectors? Any changes done recently?
If you have a FP gauge might want to check FP and see if it raises when you pull the vac line off the FP regulator and goes back down when you reconnect. Then drive the car and as you get into boost make sure that FP is matching psi of boost pound for pound. Is this a stock Bosch FP reg or an aftermarket adjustable? What Fuel pump and how old?

 

[garrett]

I replaced the MAF with the 85 MAF and the number at idle went down to about 4 or 5. The car runs better when cold. After about 20-30 minutes of driving, the car runs bad again. Fuel pressure is not a problem. As well as having a scanmaster, I have a fuel pressure guage attached to the lower windshield area and my fuel presure is good while driving and making boost. The miss getting worse when the car gets hot, leads me to believe it's a spark plug wire issue. I just can't seem to find it with a ohm meter. It's kind of frustrating.