hard starting
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
hard starting
this past summer I replaced my injectors with a matched set the orig. went bad. I have a BPP fuel pres. reg. on the car it's set at 48lbs. the car won't start when it's cold unless I put my foot on the gas pedal then it starts. If I take my foot off the pedal after it's running it will shut right off. The car is a 90 corvette L98 350 auto with some minor mods. Could the fuel pump be going bad or the ECM maybe the battery voltage is to low to send enough volts to the fuel pump THANKS FOR THE HELP I'M PULLING MY HAIR OUT
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: hard starting (pipe)
It could be a bad cold start injector or the timer circuit.
Does it idle at the correct speed when warmed up; if not suspect the IAC.
So long as the fuel rail is primed and at correct pressure, don't worry about the pump.
Does it idle at the correct speed when warmed up; if not suspect the IAC.
So long as the fuel rail is primed and at correct pressure, don't worry about the pump.
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Re: hard starting (65Z01)
My car does not have a cold start valve. After it warms up I can take my foot off the gas and it runs and idles smooth.It will not start unless I have my foot on the gas. I'll try to give more info soon
Drifting
Joined: Aug 2000
Posts: 1,251
Likes: 0
Re: hard starting (pipe)
I'd try a new (chevy) throttle possition sensor.
Its easy & about $50.
It only makes sence that the only thing your changing when you move the pedal is the TPS.As far as it working when warm,electronics are very temp sensitive.
Its easy & about $50.
It only makes sence that the only thing your changing when you move the pedal is the TPS.As far as it working when warm,electronics are very temp sensitive.
Instructor
Joined: Nov 2002
Posts: 136
Likes: 0
From: ELLICOTT CITY MD
Re: hard starting (pipe)
you might suspect the iac. another possibility is that the injectors are leaking and dripping. you said that the car had to be cold(sitting along time) and that would give the perfect amount of time for the motor to flood and there for you have to put your foot on the gas to get it to start. :confused:
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Re: hard starting (DRAGRCR1005)
Thanks for the input I just replaced the injectors this past Oct. you don't think they could be bad allready do ya. I purchased them from TPIS and got a flow matched set. When I ran the corvette challenge races at E TOWN I had a volt meter spliced into the oxygen sensor people said that it should read around .860 volts it was around .930 which means it was running to rich. When I backed off the adjusting bolt on the regulator which was set at 48lbs. the car did not start at all. Maybe I backed it off too much. Also someone said that the fuel block that the regulator is mounted on could be blocked up. THANKS FOR ANY HELP YOU CAN GIVE also is the throttle position sensor supposed to move when the key is turned to the on position also how can I test it to see if it is working. THANKS AGAIN
Pro
Joined: Oct 2002
Posts: 638
Likes: 0
From: tampa fl
Re: hard starting (pipe)
I'd do a very simple procedure that i do every once in a while......ya know...check up. put the computer into Code mode....jump the A to B terminal...wait 40secs....disconect teh IAC connector.....turn the key off now..take the paper clip out now.....start the car...warm it up...put it in D, E brake it.... and set the min idle in gear....500/600ish... might have to pop the plug out of the TB....factory tamper shizil....and then plug the IAC back in, re set MIN tps,...your set. very simple.... very useful....then do your timing. remeber to disconnect that harness by the brake booster.
Drifting
Joined: Aug 2000
Posts: 1,251
Likes: 0
Re: hard starting (pipe)
THANKS FOR ANY HELP YOU CAN GIVE also is the throttle position sensor supposed to move when the key is turned to the on position also how can I test it to see if it is working. THANKS AGAIN
No the TPS does not move when you turn the key on.There is a connector kit sold by eklers & MAD.that helps hook a volt meter to it to test it.It can be done without the connector by splicing into the wires or by sticking paper clips down into the wire conectors.
Look in eklers & youll see how they do it.
No the TPS does not move when you turn the key on.There is a connector kit sold by eklers & MAD.that helps hook a volt meter to it to test it.It can be done without the connector by splicing into the wires or by sticking paper clips down into the wire conectors.
Look in eklers & youll see how they do it.
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Pro
Joined: Oct 2002
Posts: 638
Likes: 0
From: tampa fl
Re: hard starting (nobodyunknown)
the TPS is a "mechanical" electrical part. key on or off. if you move the gas pedal.....the TPS is supposed to move the tang, or door handle part. if the key is off, theres NO electricity going through it. If the key is ON....theres electricity going through it. use a Voltmeter, set it to V for 20V. theres 3 wires...... damn i forget which ones to go to. 99% sure A, B terminal. make sure it's at roughly .5-.6V when you have the key on, and the engine off. AS you gradually give it gas....(wife, little brother, or girlfriend are helpful in this part) watch the Voltmeter and it shoulld gradually go up in Voltage.... it should have no Opens, or any spikes....smoothe upward linear is what your looking for. very easy, try it. that little TPS tester is like 75bux. you can get the splice one for like 20....but jeez, just piggy back yours for free. check the SHop manual.....if u need help.
cyaz.
-J
cyaz.
-J