You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join LS1Tech.com today!
Car cutts out bad at high rpm at running temp.!!!!!!!!!!!!!!
I have been a former mechanic on cars for 15++ years,and now I service machines in large shops.I am stumped no codes,new icm ,coil ,fuel pump,opti is a (new) cardone select with less than 5k,coolant temp, tps,wires,plugs,and coolant temp,I set my best time at track today!!!!when it was cold.The problem I have is once up to about 180 it starts cutting out bad above 5500 rpms,if its cool the car screams.I am open to anyones inputs
Seems like some kind of optispark problem. My opti threw tons of signals at me. My opti ould start screwing up the same way when it would warm up it would start popping and cutting out and around 4-5k it would do it really bad like it was running on 4 cylynders. BTW this was after I had changed it about 2000 miles before. Turned out I had oil dripping in the opti..
Its most likely the opti. Ive had multiple opti failures. Some were used and lasted about 5k miles, some were remans, lasted maybe 8k miles. Never bought a new delco. Last one I got was off ebay, brand new unit, got lucky and havent had problems with this one, but I did swap in my msd rotor. Its likely the optical eye getting "blinded" by either debris in the opti, or the bearing starting to go bad, and it loses the signal at higher rpm's. This in turn cause the ignition to breakup due to incorrect timing by the faulty info given to the pcm. If you know someone with a lab scope, hook it up to your high and low res signals then make a run. Thats the correct way to diagnose the opti's internals.
Only other thing I would suggest trying first, as heat soak tends to take out alot of these, is borrow an icm off a friends car and try that first to rule it out.
I have a new icm and have played with the plugs and gaps,done no good,and I have less than 10k mile on 9000 accel wires and msd coil.I just cant see the optical sensor breaking down in the opti but I am running out of parts to replace.I know I sound stupid thowing all these parts at it but,my car was 100% stock with even the factory plugs,and all other parts oem with 130,000 miles.
I have been told its just the bad optispark setup. I have this issue RANDOMLY. my ignition system is fine. guys say they go with the TLCC setup or whatever that uses LS1 coils and the problem disappears...
__________________ 1996 Trans Am WS6 M6 - 13.679 at 102.77MPH (11/07)
LPP Headers/Y-Pipe, GMMG Catback, PCM4LESS Tune, TPIS Air Foil, SPEC Stage 1 Clutch, STB, BMR SFCs, Boxed Stock LCAs, !TBCoolant, 3.73s, Koni 4/4s, Strano Springs, UMI Adj T/A & Reloc Xmember, Adj PHB, MGW Shifter, LS1 Front Brakes, C5 Z06 Replicas, Full Sound System! 1986 Honda VFR750 - Jet Kit, K&N, Hindle Stealth full exhaust, -1 fsprocket. 89.3HP
Originally Posted by HioSSilver
There is no clear line that sra is better than irs at drag racing
I finally got it fixed,bought a gm hp new version from a guy that had some parts a guy bought,to do a swap and gave up the project $75 bucks,my car runs perfect,idles better and no low rpm surging,and screams up top.I am on my 6th opti,in about 11k miles 3 junk ebays,none ran right,2 cadones first ran ok but just laid down with 5k miles,was covered but has not ran right since,and I chased everything else looking for the prob.,anyway never run anything but a gm or msd opti.