Zach/90\irocZ

iTrader: (6)

ok i change o2 sensor , iat sensor, install air intake temp, and coolant temp sensor all new and new 160 thermastat, and in morning stater strugles to start engine warm starting is ok and im idling at 2000rom and sumtimes surge up to 3000 rpm, im waiting for new egr valve and map sensor and egr seloniod, and driving on freeway coolant temp at 160 to 180 but at idle it oveheats or when driving stop and go radiator is new and flush and put 50/50 coolant fan turns on around 200 any ideas wat the issue cold be im also getting 51 code i know its bad prom i got new ecm and prom just trying to bypass vats going to do that today

thank you this forum been awsome help

HM3 (FMF) James

ex-x-fire

Its over heating b/c of high idle, did you check for vacuum leaks? Iac maybe bad.

Zach/90\irocZ

iTrader: (6)

yea it was idling high then i took out old iat and clean a it then put back in abd it idle fine but decided to go get a new one at autozone and thats when it started im try to exchange it today maybenew one went bad i check for vacum leaks and all the hoses and there all good

UnderCover89TBI

iTrader: (25)

I wouldnt run a 160 thermostat either. especially when your fans arent turning on til 200* but the high idle equating to overheating sounds right. Go over the intake, tbi, with carb cleaner see if you can identify a vacuum leak.

Zach/90\irocZ

iTrader: (6)

yea i did look over all the vacum lines they look good only one im not sure about is the vacuum line that goes out the manifoled in between tbi and Distributor and goes to a T where another hoes goes to firewall

mikesanto70

I have a 1991 camaro 5.0 TBI LO3 auto, it is idling high at 1200-1300 and it stumbles from a start. At 35 mph i can let of gas and it will maintain speed of 35 if road stays flat. A friend said it might be a vaccuum leak and to test with spraying starting fluid on them and the tbi base gasket to see if it revs up. I have new plugs and EGR valve, so can possibly rule them out. Any suggestions would be appreciated a lot!

ex-x-fire

Remove the tbi unit, they have been known to suck the gasket in. That way you can be certain of no leaks, plus you can clean it good too.

one92rs

iTrader: (5)

loosen the coolant temp sensor from the intake. very slowly pull the sensor out and see if coolant starts to leak immediately when loosening it. if it does then the cooling system is more than likely bleed. if you pull it up and it does not start leaking coolant immediately then the cooling system is not bleed out.

mikesanto70

I cleaned the IAC and while also spraying brake cleaner near the base of the TBI unit it revved up a little which told me I had a TBI Base Gasket leak too. So after cleaning the IAC it still was high, i went into the garage to call pep boys to check on base gasket then got in car to go pick it up and it was idling normal again. The IAC cleaning did the trick, but I still had a slight base gasket leak so I changed it and sure enough, it needed to be done but was not terrible, but needed it, so now it runs like a champ. Thanks for the help!!!!!!
Mike Santo

mikesanto70

My high idle condition has returned and worse than ever, I have a new IAC, EGR and a new TBI base gasket, ran fine for about 6 weeks then when i started to drive a little aggressivley, the high idle returned and it is rough starting too which is a new condition. any ideas such as computer or coolant sensors? idle is at 1500-1900,

ex-x-fire

Check the tune up parts.
Recheck for vacuum leaks.

mikesanto70

I did, getting pissed too because sometimes it returns to normal for a day or so then all of a sudden the mo fo is doing it again, WHAT THE F IS IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!

ex-x-fire

Check the grounds, loosen them & retighten them. There are ecm grounds that are at the back of the heads.
You might have to get it scanned to see the iac counts.

mikesanto70

yeah, thats about all thats left to do, man I'm going back to a carburator, going to build a LQ9 6.0 w/ a Carb, screw all this computer ****!!!

86T/A_Ram_Air

Still need a ECM for that. LS engines are distributorless ignition. EFI is not that bad