1996 Mr.Pink

[NocturnalGTU]

What coils were you running? Since you weren't actually feeling a detonation I wouldn't be surprised if it was just electrical interference. But then again it could be something completely different if the coils didn't solve your problem. I've been thinking a lot about this issue you're having, and it could also be your torque converter clutch acting up (if you still have one, I don't have the time to memorize what you have done to your car.) If you aren't getting the issue on the track, but are getting it while cruising that could very well be the issue. A TCC "chattering" will cause a very strange load on the engine which will cause the engine to chatter a little right along side the TCC. Easy to eliminate though, just unplug the TCC solenoid and drive around like you normally would, if it still happens, thats not your problem.

[3X00-Modified]

There is no just "unplug" your TCC plug on a 4t60e, This is a 3000k stall PDQ converter so not having the lockup is a bad idea, and the RPM's will NEVER drop down to the affected area with the TCC unplugged... so really I can't test that.

1988GTU, No I have not checked my injectors as of late, but as I've noted I can not hear anything when it happens, and you cant feel the detonation either... I feel the timing retard, but if I pull the sensor the car runs smooth as silk all the time. And the chain slapping the guide is the issue I had before I changed the chain, it sounded like a bad set of lifters... so as noted I have had that issue before and it did not affect the knock sensor any. It's also all stock parts in there so there is no way anything can interfere with the cover, the cam has a hold back plate, and the crank is obviously not walking because that would generate god awful noises since it would end up hitting my crank scraper.

The coils I had were replacement ones I put on my red car probably back in 04 or something... a LONG time ago. They were also a miss matched set so its nicer to see 3 of the same on there now.

I'll take it again today and see how it runs. This may also be a noise that is caused by my headers and something I may not be able to eliminate so I will be forced to put the knock sensor on a switch and only use it when running at WOT.

[Barry]

What I did to time my WOT and high load low rpm ignition areas was go for a highway cruise and slowly advance the area you are driving in until you hear knock. Even with my headers, minimal sound deadening, and an exhaust leak, the knock is pretty apparent. As soon as you get a feel for what it sounds like you will see. Then I back it off 3-4 degrees in that area to compensate for a crappy tank of gas or really warm temperatures. I do the same in all my common load ranges and WOT. It was cool to feel the HP gained WOT when doing some timing work.

If your real serious and don't mind looking gay, you can take a small copper pipe, hammer one end flat and drill a hole in it. Now bolt that to the motor where the knock sensor would go. Now run a rubber hose from the copper pipe to a set of noise canceling headphones inside the car. This works well for louder engines, turbo motors, etc.

Lastly, you could log EGT temperatures. A local tuning shop here does not use any knock sensors. They tune strictly with a WBO2 and a EGT probe. They build high horsepower imports every day and do it well.

Knock Sensor on a wot switch is a interesting/creative idea. I like that.

[3X00-Modified]

I wasn't thinking of putting it only on a wot switch, but simply one I can get to when I go to the strip, because trying to bend your wrist below the screaming hot headers to plug it back in is a bitch... my hand will not like that much.

So far on my way to work today, and 3 different trips total... one home on higway after doing coils, one to my parents this AM and then one from there to work, I was UNABLE to get the KR to come back..

I'm going to get the old coils now so I can ohm them out and see if anything is obvious on that front. I'm not calling it solved yet, but the odds are getting better since last time the second trip I took after doing the plugs the KR was back and same thing with doing the insulation on the coil bracket for the mean time.

I'll keep you updated and Yes Barry Timing tables is something I REALLY need to work on since I know I'm not peaked out quite yet. What do you run at WOT?

[Barry]

I cant be sure right now, My tuning computer is at home. Ill find out though and we can compare.

[3X00-Modified]

Well... Don't assume that all coils are created equal... out of the three I had on my car before, 2 matched and one was an odd ball... The one odd ball matched the GM coil specs exactly... The two others had a resistance of 8.5k-8.6k on the Secondary winding... and the GM ones as noted are only 5.6k all the primary windings ohm'd out at 0.5-0.6 so similar to the GM ones.

And so far I have not been able to re-create this KR symptom... I hope to god this was it.

Some say failure starts in the 10k-14k area of the secondary windings, but at the same time they say values can varry from application to application, so I'm wondering if simply having that miss matched setup was causing some interference somewhere... I wonder what else this could have been doing to my setup.

[3X00-Modified]

So yeah I went an put my other Taylor wires back on and pulled the TR6 plugs and put back in the GM Iridums since I'm not spraying right now and took the car for a ride and the bog/KR symptom is back... So I said F-it went to advanceauto and picked up a new set of Accel 8mm red wires and made up a new set as well as found a nice one of my spare ICM's and swapped those two things out.

So far so good... I've only driven it to Thompson and back home last night... so I haven't used it alot yet but I got the KR to come back before on one quick ride down to Home Depot and back, less than 15 min... So if I haven't seen anything yet I think thats a good sign.

[Cliff8928]

Man, don't you know about only having one variable at a time so you can figure what the problem was...

[3X00-Modified]

Well I attempted to do that... I started with the wires... Thought that fixed it then it came back... so I moved on and tried coils, leaving the wires I had swapped in there... and that felt even better on the higway for a longer period of time, SO after testing the coils and seeing what ohms I got on the secondary windings, I assumed I had found the culprit so I could put my red wires back on and take off the obnoxious yellow Accel ones. So I did that as well as changed the plugs over to stock heat range for street driving since I'm going to PA this weeked. Now judging my past experience and testing, the wires should be 100% fine... So I take it for a ride after doing the plugs and wires and almost immediately feel the bog/KR on the highway again, as well as around town in one area. So I said screw it, I'm getting rid of these Taylor wires because they are over 5 years old and I've pulled my fair share of boots apart and I'm tired of them. As well as I figured it wouldnt be a bad idea to eliminate the ICM from the story since that was paired with the tested bad coils.

I was running out of time to keep testing before needing the car this weekend, so I opted to technically replace the whole ignition system from ICM to plug and all I spent money on was the new wire set. I already had the ICM coils and factory Delco Plugs.

I know the plugs weren't the issue, but I know I'll get better mileage with the proper heat range in there plus those TR6's wear out quick. I need a new set now anyways because I broke one removing it, the wrench moved and snaped the top insulator off... Whoops

So yes I typically follow that process of elimination, but this time I just need it done for today. I will probably inspect the wires closer, and ohm test them and I may even throw them back on sometime to see if the KR comes back... I will also be testing that ICM but as noted I don't have the time to do it right now.

[Barry]

Speaking of coils...

I am aggressively driving some back roads and all the sudden it starts running like poop, like its missing a few cylinders. I come home and immediately check the coils. they read 5.6 5.6 and OPEN. Swapped in a new coil and were back on all 6 cylinders again.

I have seen them throw resistances that are out of spec before, but I have never had one totally take a crap like that.

I may try to run a 3500 coil. I have 2 of them and theres a guy on 60V6 running megasquirt and 3500 coil.

[heavywoody]

What's different about the 3500 coils?

[3X00-Modified]

It's one soild coil ICM intergrated too.

[Cliff8928]

There's no discrete ignition module on the 3500. It's only connected to power, ground and the 3 signals from the PCM for each of the coils.

[mickaz]

isnt the 3500 coil looking for the 3500 crank signal? would you have to hook up you 3500 CPS?

[3X00-Modified]

If there is no ICM then no, the PCM looks for the 3500 crank signal, so you would have to wire in an 04 3500 entire PCM to run the motor.