We are getting closer to figuring out the electrical gremlins in my '90 since I had the 383 SR motor built 2 years ago...Gathering data with the Ease software showed that the computer was pulling our 5* of timing every time the throttle was spiked to about 70% +. This was happening even when engine was cold and running 10% rich! How does that happen? A bad KS? A short in the line? Wrong KS for the year of the car? Something loose that I can't hear over the exhaust noise?
Also, the scan tellls us that there are too many Canister purge cycles. Could this be related to yanking all the AIR components and not programming for that?
(Same post in C4 section)
Re: Knock sensor and Canister help needed (DOCTOR J)
Dr. thanks for the insight. Unfortunately, in this arena I'm out of my league and am just regurgitating what my hacker found. So I don't understand some of the acronyms you're using. :confused:
Also, I don't think that the inference was that the canister was necessarily related, but just another observation. It just raises more questions.
Unfortunately, a lot of these issues were generated by the boneheads that did the install. (worked for the engine builder) There were other wiring, and plumbing related issues created at that time that did not exist prior to the transplant. Keep the ideas flowing!
Re: Knock sensor and Canister help needed (h rocks)
If there have been isues with the install....then it may be worth checking how tightly the knock sensor is installed ( if not already checked).
If it's cranked in there it increases the sensitivity.
One trick to decrease sensitivity if needed is to install a 90deg pipe between the block and the ks.
I've found that quite a few 383/406 engines must just have different enough harmonics to require less ks sensitivity-wether due to full lengh headers or what???
Of course check for loose things banging around also....
Re: Knock sensor and Canister help needed (drive it)
Update...New knock sensor with loctite patch removed and wrapped with Teflon torqued to factory specs. (~15-17 lbs/ft) New pigtail to replace fried wire. Found intermittent open on MAT connector. (that was "fixed" by the bone heads) Plugged the broken air tube holes we found on the right side headers.
Took it out for a shakedown. Squeezed on the throttle to avoind possible knock. A little more, more...no knock. Got some gas. Pulled out of the station easy, in 2nd gear about 30-35 squeeze it a little more aggressively. The thing goes sideways bigtime. (Two men and a full tank, ~ 4,000#)
Got it on the freeway and hit it a little harder. It pulled HARD to 6,000(Superram) in any gear. cruising in 4th and 5th were the same. HOOF'INGRAY!!!:party:
It seems like it wants to run more but my guess is that there is still a little bit of false knock retard going on due to the headers, SM Alum FW, & RR's. At least it seems like we're on the way.
Didn't get a scan due to the "fully charged" laptop batteries both apparently being cooked. :cuss But I'm really feeling quite good about the prospects for the motor to be what I had expected. :yesnod:
Corvette Store
Knock sensor and Canister help needed
