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Discussion Starter · #1 ·
Thanks for all the suggestions and thoughts on my earlier post regarding the injested MAF screen retainer. I screwed off this afternoon, replaced the 52 with a 45, cleaned out the IC and was back at the strip tonight. Still had same problem. After changing out fuel rail & injectors, ecm, coil pack/mod./wires, plugs, fuel filter, turbo, chips and every other possible thing, I've still got the same problem.

Hit 12 to 15 pounds of boost, the knock retard goes to 21 to 30 degrees and car falls flat on it's face. EGT's in the low 1300's and 02's in the .830 area. It's clearly not detenation.

For kicks, I stabbed the accelerator in park bringing the RPM's up to around 5000 a couple of times. I get 30 degrees of retard in park (no load)! I run nothing less than 114 octane gas and several of us run our cars from the same drum so I know it's not dirty or contaminated fuel.

Keeping a close eye on my EGT's and 02's, and deliberately running richer than normal, I pulled the wire off the Knock Sensor. The car ran through the gears better than I could ever remember. Changed the knock sensor and wired it back up. Same problem as before. Pulled the wire off the new sensor and the car screamed.

I'm starting the think this 218/218 flat tappet cam I just put in is so loud the knock sensor thinks the racket is detonation. Anyone out there with this cam that has had similar problems?




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[This message has been edited by Jack Evers (edited November 22, 2001).]
 

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Discussion Starter · #3 ·
Thank you, Ron. I'll check these things out.

Interestingly, while I've been fighting this problem for some time, I did run four back to back 11.4's in Vegas (4500 ft density altitude) the 10th of this month without noticeable KR. Fifth run it was back to it's old self (spitting, sputtering, very high KR even at low boost).



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Discussion Starter · #7 ·
Originally posted by Steve Wood:
You replace the rockershafts, ever? My 221 deg cam did that...actually peaked around 2800-3000. It got a lot better when I put new shafts on it but still did it a little.

I dialed the ME kr lockout up to 41 mph and hid the problem as it did not drop far enuf back on shifts to fall into the rpm range again.
Steve/Ron...I've got Mike T's HD rocker shafts with factory rocker arms. Lifter noise at idle not much greater than factory cam. I guess it's prolly not the cam as (I mentioned in earlier post), car made four strong back-to-back runs in Vegas and then reverted to it's former problems. The problem seems to be intermittant. Ron, I did jumper the grounds and that's not the problem. The coil module was swapped out earlier.

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Discussion Starter · #13 ·
The suggestions made by you guys have been very helpful and I think we've found the problem. The rear coil pack bolt, the one that sits on a "U" shaped bracket straddling the knock sensor was missing. While the front two bolt held the coil seemingly solid on the motor, at RPM the missing third bolt allowed the coil to bounce just enough to feel like detenation to the knock sensor. Replaced the missing bolt, hooked the knock sensor back up and things are back to normal. The little subtleties of these cars are mind boggling.


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