starting up

[formulaMARK]

My car starts up fine when it is cold but when it gets to running temp and you turn it off and try to start it up again it wont start sometimes. Anyone have any ideas what could be wrong?

[j0n]

i had the same problem w/ my lt1...turned out to be a bad coolant temp sensor...dunno if u have one of those tho

[The Fixer]

Does it crank, and not turn over? Or not even crank? If it doesn't even crank, it could be the starter solenoid going bad. It's a common GM problem. If you need to replace the starter, get a Vette LT1 starter or mini-starter. Better design and lasts longer.

[Batman]

Does it drive OK when it gets warm? Or does it seem down on power? IF you still have a converter on it make sure it hasn't collapsed inside. Just tap on it and see if there are any rattles.

[formulaMARK]

It drives fine when its warmed up.

[Squirrel]

dont know bout 3rd gens, but do you have a heat shield on the starter?....starters arent big fans of heat and get pissy when they do get hot

[Fasterthanyou]

All of the above and one more thing to check is the wiring to the starter itself. If it cranks over slowely, check the wiring, you'd be suprised how many miles a stock starter can last with a good battery and good wire contacts.
If it just isn't firing and the cranking is fine but no SES light, well, does the SES light even work? Too often previous 3rd gen owners will remove the bulb or let it burn out. You've got a 91 so it doesn't have a MAF (which is GOOD, I hate expensive finiky sensors) so if you bring the car to the next meet you can hook up my scanner and see if there are any dead sensors.

[84HOtransam]

All of the above and one more thing to check is the wiring to the starter itself. If it cranks over slowely, check the wiring, you'd be suprised how many miles a stock starter can last with a good battery and good wire contacts.
If it just isn't firing and the cranking is fine but no SES light, well, does the SES light even work? Too often previous 3rd gen owners will remove the bulb or let it burn out. You've got a 91 so it doesn't have a MAF (which is GOOD, I hate expensive finiky sensors) so if you bring the car to the next meet you can hook up my scanner and see if there are any dead sensors.

i talked to mark on the phone about whats wrong with is car..the way he described it sounds more like an ignition or fuel problem then a started problem..im gonna be back from school this weekend so i can take a look at it with him..

ill also make sure theres a bulb in the ses light. and see if im getting any codes..

[9secfirebird]

doesnt sound like starting problem to me.

[Fasterthanyou]

doesnt sound like starting problem to me.
You sure? He said he's having starting problems... :)

[84HOtransam]

doesnt sound like starting problem to me.

theres a starting problem but no problem witht the starter itself...

[84HOtransam]

ok i checked the car out when i was at home...

it starts cold fine...we let it warm up then turned it off and it wouldnt start again..

the ses light was on and it threw a 15 code... low temp at colant sensor...

any ideas?

[Fasterthanyou]

I have an idea... replace CTS (coolant temp sensor).
If the ecm thinks the engine is cold it stays in open loop. When it does this, you'll be running richer than stoich hence the flooding of the engine on warm restarts. Try this for me and see if it works; Floor it while you're cranking after it fails to start warm. Obviously don't keep it floored when it catchs and fires but that should put the ecm into "clear flood" mode. When it's in this mode it doesn't fire the injectors or it commands a really high AFR which doesn't fire the injectors. When I mean floor it I mean peddle to the floor and no lifting, no pumping, just keep it floored until it starts.
Then replace the CTS sensor or first try cleaning the connector.

[84HOtransam]

I have an idea... replace CTS (coolant temp sensor).
If the ecm thinks the engine is cold it stays in open loop. When it does this, you'll be running richer than stoich hence the flooding of the engine on warm restarts. Try this for me and see if it works; Floor it while you're cranking after it fails to start warm. Obviously don't keep it floored when it catchs and fires but that should put the ecm into "clear flood" mode. When it's in this mode it doesn't fire the injectors or it commands a really high AFR which doesn't fire the injectors. When I mean floor it I mean peddle to the floor and no lifting, no pumping, just keep it floored until it starts.
Then replace the CTS sensor or first try cleaning the connector.

thanks...where is the sensor on the engine?