Ok im having some issues maybe someone can help me with, nobody seems to be able to answer it, under a cold start in weather under say 50 degrees the car misses like crazy and randomly idles itself up to about 3k for a few seconds then back down and it will do that a few times every minute or so, it doesnt act this way in warmer weather, also theres a grinding noise in the cabin around the shifter, it stops when the car stops rolling, its a stock 98 t/a ls1 with a flash, can anyone point me in the direction of what could be going on, and my location is the mississippi gulf coast to help with determining my climate since that seems to be a factor

 

Welcome to LS1tech! SEARCH will be your best friend around here.

Did you check the items suggested in the other thread/section you posted this in?

Have you scanned for codes? Sometimes you'll have codes that will NOT illuminate the SES light.

Grinding-is this an auto or stick car?

You described this car recently acquired and in rough shape. Have you performed all the usual "just bought it" items like fluids & filters change, plugs, wires, general cleaning, etc?

 

I couldnt find my other post i thought it got deleted because i put it in the wrong section or something, and search has yet to help me on anything even locating my old post, everything i search for is totally irrelevent to what im actually looking for, its an automatic, I have done tune up, no codes are being thrown, ive had it hooked up to live data and nothing is out of the normal, ive done all the used car stuff, changed plugs, wires, air filter, oil changes, trans fluid and flush, new motor mounts, new rear springs and shocks, replaced some vac lines for the pvc system that were ate up, done a good degrease and cleaning of inside and out And i do appreciate pointing me in a halfway right direction,

 

OK. You worked on the PCV lines. Perhaps a line is open sometimes and causing a vacuum leak. This might explain the high idle.

Did you change the fuel filter?

Noise around the transmission: Does it happen when rolling in gear or rolling in neutral or both? Does it in reverse?

 

are your brake rotors weathered or rusted? pitted rust on rotors will scrape against the pads though they are not engaged.

 

All lines are good.
it doesnt do it in higher temp weather, its only on really cold mornings. i know what bad brakes feel like its not the brakes its somewhere in the tunnel under the shifter, it grinds when im rolling in neutral or forward gear, as soon as i come to a stop it stops, almost sounds like a dry speedometer sheeth when its dry on grease or something
And yeah fuel pump and filter was upgraded about 5000 miles ago with a.walbro, and i run non ethonol fuel in it after i flushed the entire fuel system

 

Tried cleaning the maf and map sensor?checked injectors?cam sensor?crank sensor?rear 02 sensor wires?checked plugs?wires?

I had a cracked spark plug cause me headaches onetime.They were new and I kept looking over it because I just changed them not knowing it was cracked.

 

Will those things malfunction just because of colder weather, and ill be getting out there tomorrow and be.looking over all that, but when i had the live data computer hooked up maf, map, timing, o2 sensors everything was operating great according to the specs in the service manual, thats what got me beat

 

good point... i cracked one of my plugs during my header install... was baffled for a day and a half til i scanned the ecu and pulled a code for what cylinder was miss firing lol