My idle is a little rough and sounds a little off. A burnt wire is most likely the cause if it is missing. In the past when I am burning a wire, the car accelarates poorly at WOT at 1500 RPMs in sixth gear. It is performing fine but the idle does not seem right, maybe I just need new plugs, a friend changed my platinums 10000 miles/ a year ago. What do you guys think?

 

I had the same problem you have, 3 years, 5 diff. dynos, 3 sets of plugs and wires, 4 dealerships & 2 automotive shops later... The dyno at RPM Engines picked up the Miss my car had all along. The miss showed up as (gaps) in the dyno run.

I had given up on fixing the problem because the dealerships said nothing was wrong... :( A year later when I was at RPM again for another dyno day. I had problems with the new Mods I had and needed new Valve springs installed. I told them that they were the only shop that had picked up my miss on the dyno and could they please find out what the problem was. Brad, whipped out a small hand held inductive detection unit. When the unit was touched to the spark plug wire the little light flashed each time the coil fired. All of the wires had a steady spark except #7. Once the Coil was replaced the car ran right!! :eek: I was so happy!! :) All this just transpired a few weeks ago and I really enjoy driving my car now. :yesnod: Not to mention that the car is much more powerfull now that it is running on all 8 cylinders. :rolleyes: Here is a copy of the before and after the valve springs were replaced.

Now keep in mind that the Dealerships told me all along that nothing was wrong with my car including the coil packs. If your car runs like mine did and you have already installed new plugs and wires... the coils are where I would concentrate my efforts now.

vetterdstr :cheers:

 

This is what I felt like I was driving for the past 3 years while my car ran like S-it...


vetterdstr :hat

 

:lol: :lol: :lol: :lol: :lol:

 

You gotta love the mobile craper :lol:

 

I had mine on the Dyno Friday. It produced 303 - 308 Std HP over three runs. I do not think this was corrected for barometric pressure. It also had a severe dip in the graph at 4400 and 4800 RPM. I was severely bummed :cry With the Halltech, Corsa's, Granatelli MAF and B&B Headers, I thought I would see at least 320-330. I found 2 wires (7 and 8) I believe, that were bad later that day. # 8 burned through on the last run. I have since replaced the wires and added heat resistant covers to the wires.

I am really/really hopeful that this robbed me of a few horses at the Dyno, otherwise I am at a loss as to where these horses have gone. I will go back and re-Dyno after the Holidays.

What do you think, is it possible that a couple of bad wires can effect the Dyno run to the extent of 10-20 horses, or am I just Skrewed :rolleyes:

 

The PCM stores current/history misfire data :yesnod: If you can get someone to retrieve the data,you will know for sure if you have a missfire...

 

Vetterdstr,
I spoke with Chuck Mallett last summer at Funfest. He told me that after you burn a wire a couple of times that it adversely affects the coil thereby decre asing the amount of voltage through the coil by 10 to 20% and also decreasing performance. He said it would be a good idea to replace the individual coils wherever a burn had occured.

GReg

 

You need to install a MAFT, & tune that car. With all the things you have added to the car you would be running lean which would lower your fuel numbers, take away your timing, and screw you out of HP. One of the things I had on my car which didnt help me at all was the Granatelli MAF. I took that off and now use it as an ashtray.

Let me know how it works out for you. If you have any other questions please contact me.

vetterdstr :cheers:

 

C-5, I respect you... but I have to tell you that my computer did not report misfires. Yet the Coil was not working correctly. This is why the 4 dealerships could not find a problem with the Tech2 device.

vetterdstr :cheers:

 

Chuck is a great guy and knows his stuff. In all the time I had my car a wire was never burnt. It ran bad from day one with the OEM wires on it. The #7 coil I had didnt seem to have a reduction of voltage... it flat out hand a intermittent miss to the spark interval it was made to do!! :eek: If what Chuck says is true... SANMAN1 has a couple of coils to replace. They sell for $75 each at the dealership.

I do have to tell you guys that once the problem was solved... my dealership did insist on making GM pay for my shop bill. :)

vetterdstr :cheers:

 

C-5 Tech,
Will the computer tell you if you have a coil that needs replaced or which wire is burned?
Greg

 

No,the PCM can tell you which cylinder was missfiring with the history data.One still has to diagnose the culprit :yesnod:

 

now's a good time to ask santa for ScanEase software so that you can scan your car yourself. once you become proficient with it, you will be able to diagnose very easily. once you know which cylinder(s) are misfiring, you can start swapping parts, one by one, over from a known good cylinder until you solve the problem. EASY!!

 

I spoke with tom at Ken Fritchner's, he said the individual coils cost 48 or 40 a per unit or 40 if you buy four of them. I think that I am going to bite the bullet and get four of them.

Happy Holidays!
Greg

 

Let us know if it works out for you ok?

Happy Holidays !! :)

vetterdstr :cheers: