Okay I'm sure somebody has to have this problem although I rarely read about it... I need to break down the entire story so you can fully understand so please bare with me. About 4-5 months ago my car had a bad miss. It was all throghout the power band. While crusing, you could hear small pops and hesitations on light throttle. Going WOT cured the small hesitations but the power was not there like it should be. I said to hell with this miss and I replaced the entire ignition system, plugs, wires, coil, ICM, MSD digital 6, and the infamous opti spark. Everything was bought new from GM or MSD. For the three weeks after I had all that ignition stuff on the car, I have never felt the car so fast... every time I hit the gas it amazed me even more than the last!!! I'm sure some of you guys know that feeling....

**Intermission**, grab a snack or something hehe.

Okay so now, three weeks goes by, car is running great. I made a mistake by letting my boss "heat up the slicks" in my car. He smacked off my rev limiter for a good 30-40 seconds (the MSD rev limiter spark cutoff not the stock fuel cutoff) doing both rolling and standing burnouts. From the point on the car never ran the same and on top of that he ruined my friend's ET streets and heated the slicks to the point where I'd rather have kumhos. I changed the plugs but it was merely a temporary burst of power. My old boss was another story...

Fast forward to today. I bought my eclipse to drive around so I can garage the T/A. I finally got around to installing a Delteq (finished 45 minutes ago) thinking that would fix my problem. It was behaving exactly the same way it did before I swapped all that brand spanking new ignition stuff on it. So to make a long story short, 5 or 6 hundred dollars later I have a car that still has the same problem.

Now here are the symptoms:
-I notice many people saying that when the car gets warm, it runs ****ty. My car runs horrible when its cold. Just to get the thing off from a stop you have to ride the clutch out a little bit because it wants to just huff and fall flat on its face.

-Under light cruise, there is an audible miss (everything is audible with true duals). If my exhaust was morse code it would look like this ------_----_-------_-------------_, where the _ is a miss.

-The car has no EGR, no AIR, no cats. I have claned the MAF and TB each about 5 or 6 times since I have owned the car. The fuel filter, PCV, o2 sensors are either close to new or lighty used but nowhere near abused or beaten. I used to work at a strictly f-body/y-body shop so I know how to take care of these cars and this is stumping me. I would have bet money that the ignition was the problem but now I can see that it is not.

-I CAN'T BELIVE I FORGOT THIS!!! Probably the most annoying yet most identifiable symptom only comes under heavy load and low rpms. Say if I am in first gear rolling at 1500 rpm, if I stab it in an ideal condition the car should wake up and start spinning the tires. However, it bogs VERY hard the moment I give it too much load then recovers very quickly to start a half-*** pull. It's like a fat miss, like the spark got up and ran away under high load, low rpm. Now I know it's not good to run an engine like that, but regardless it should not be doing that and when the car was stock, or when the car was running well, it never did do that...


Here are some things I think it could *possibly* be...
-TPS out of range or bad (I have set the tps to read perfectly, around 0.6v at idle and around 4.5v at WOT so I doubt its the problem but there is always the possibility)
-Fuel filter, like I said I'm the type that keeps up on maintenance. At the most, it has 10 or 11 thousand miles on it but the problem has been here for well before that.
-One of my exhust primaries on my driver's side manifold got dented in by a piece of wood on the freeway a while back. I'd say that the one primary that got dented bad is probably closed off a little more than halfway but still has room to breathe enough to flow exhaust for light throttle without causing a miss.
-On my passenger side o2 sensor (I just found this out while installing the delteq) the connector from the extension to the car's harness is missing the little rubber weatherpack insulation.
-My passenger side long tube lightly touches a wire loom (this never caused a problem, those 3 weeks wen the car was 100% was with the Hooker's installed)



Other than those Im out of ideas and I'm not tryng to start throwing misc. parts at the car. I have always kept this car in tip top running shape, never skimped out with cheap parts or any of that stuff. Please help me fix it, those 3 weeks when it was running good were some of the happiest days of my life

IF ANYBODY CAN POINT ME IN A DIRECTION THAT FIXES THIS PROBLEM, I WILL MAKE IT WORTH YOUR WHILE!!!!!!

Thanks for your time!

 

I have 2 ideas for u to consider.
1. When your boss ran the **** out of your car it might have heated the headers up enough to melt the wire loom that wouldnt usually melt under normal driving conditions.
2. Check your ignition control module.

This is why i dont like to just replace a whole crap load of parts at one time to fix a problem. Because once its fixed then u dont know exactly what was causing the problem if it ever happens again bc you replaced so many parts at once. Have u checked your fuel pump lately???

 

did you check fuel pressure? If it is getting good spark, then it might be a fuel issue.

I would also pull the valve covers to make sure that all valvetrain stuff is OK. Check the valve lash, and make sure you dont have any obvious valvetrain probelms. I broke a valve spring and the symptoms were alot like yours. It also sounds like what my car used to do when a poly lock backed out.

Dont be shy to assume hardware damage. I know its easier to assume its a sensor.

 

Good advice disco. I will check out what is beneath the valve cover tomorrow evening.

I have an update on the car. I need to reroute a couple plug wires from the delteq that were too close for comfort (to the header). I decided to check out the MAF. Turns out the resistors were pretty damn dirty! The MAF must have ampllified whatever the real issue is because it feels like the missing went down like 75% and it's pulling A LOT harder now than it was before (not where it should be though but it's a breakthrough and i'm happy!) I still feel some slight stuttering and missing however and I want it outa here.

What method do you guys use to find zero lash for the rockers? Just curious how other people do it. I usually go up and down until it gets close then I start spinning the pushrod until I feel a drag. Right now I have the comp r's set at 1/8 past 0lash.

Could that large dent in the exhaust primary cause these symptoms? The dent is more like a cave-in actually... I think about 60-70% of the flow is bottlenecked right there. What do you guys think about that???

 

well comp-r lifters are CAKE to lash compared to normal rockers for me. I do it while the motor is running. The spin the pushrod never comes close for me. I back the polylock until it is loose, then tighten it until you feel the pressure (it will become tight quickly). Then maybe a HAIR more. You can overtighten them by hand, just dont put much force at all into them.

If you want to NAIL them down perfect. Then get a get a .0015 feeler guage and then set the preload after that. Thats what I do on really high reving motors.