Car Acting Up!!!!
Thread Starter
Racer
Joined: Apr 2005
Posts: 435
Likes: 1
From: Worth IL
Car Acting Up!!!!
Well yesterday morning the weather was nice so I decided
to take the Vette to work, when I tried to start her she cranked
a little longer but she started and she idled high around 1400 rpm then I notice the check engine light came on
well to make a long story short I ended up taking my other car.when I came home from work that evening I started her up and she started
kind of eratic but after a while she idled alright, also the check
engine light didn't come on this time!!!
so today I took her out for a drive and she idled rough!
also when I start her she'll die out unless I stay on the gas
and after a while she'll idled normal!!!
does anyone here know what could be wrong?????
Thanks in Advance.........Poncho.
to take the Vette to work, when I tried to start her she cranked
a little longer but she started and she idled high around 1400 rpm then I notice the check engine light came on
well to make a long story short I ended up taking my other car.when I came home from work that evening I started her up and she startedkind of eratic but after a while she idled alright, also the check
engine light didn't come on this time!!!
so today I took her out for a drive and she idled rough!
also when I start her she'll die out unless I stay on the gas
and after a while she'll idled normal!!!
does anyone here know what could be wrong?????
Thanks in Advance.........Poncho.
Racer
Joined: Aug 2002
Posts: 432
Likes: 0
From: Lancaster CA
i would start by disconnecting the battery to reset the codes. if the code is still there when you start it back up, take it to an autozone and get them to pull the codes for you. then diagnose from there.
Shawn
Shawn
Race Director
Joined: Jun 2005
Posts: 17,640
Likes: 1
From: Lenoir City TN
St. Jude Donor '08-'09-'10-'11
Looks like you got an 84, correct?
I believe you got two Idle air control valves that might be acting up, pull the codes before resetting them then post what you get, Damn where is CFI-EFI, he's the genius when it comes to the cross fire engine.
I believe you got two Idle air control valves that might be acting up, pull the codes before resetting them then post what you get, Damn where is CFI-EFI, he's the genius when it comes to the cross fire engine.
Thread Starter
Racer
Joined: Apr 2005
Posts: 435
Likes: 1
From: Worth IL
Originally Posted by SSLT1KID
i would start by disconnecting the battery to reset the codes. if the code is still there when you start it back up, take it to an autozone and get them to pull the codes for you. then diagnose from there.
Shawn
Shawn
Thanks
Thread Starter
Racer
Joined: Apr 2005
Posts: 435
Likes: 1
From: Worth IL
Originally Posted by rspreng86
Looks like you got an 84, correct?
I believe you got two Idle air control valves that might be acting up, pull the codes before resetting them then post what you get, Damn where is CFI-EFI, he's the genius when it comes to the cross fire engine.
I believe you got two Idle air control valves that might be acting up, pull the codes before resetting them then post what you get, Damn where is CFI-EFI, he's the genius when it comes to the cross fire engine.
the Idle air control valves ? and where the heck are
they at??? as you can tell I'm just learning how to
work on me vette!!!!
Thanks in advance Poncho.....
Le Mans Master
Joined: May 2003
Posts: 8,175
Likes: 237
From: Philadelphia Burbs
Cruise-In V Veteran
St. Jude Donor '06
Originally Posted by rspreng86
Damn where is CFI-EFI, he's the genius when it comes to the cross fire engine.
Try posting in C4 Tech, maybe that'll scare him up...
Team Owner
Joined: Sep 2003
Posts: 20,179
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Originally Posted by rspreng86
pull the codes before resetting them then post what you get, Damn where is CFI-EFI, he's the genius when it comes to the cross fire engine.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by rspreng86
Damn where is CFI-EFI
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Burning Brakes
Joined: Sep 2006
Posts: 1,202
Likes: 3
From: MD
The IACs do throw a code. If the commanded idle of 750 or so is not reached in xx seconds (I think it's 10 or 15) the car will throw a code. I believe it is a code 35, but check the manual on that one. When you reset the codes, by disconnecting the negative lead of the battery for a few minutes, it will also reset the IACs. Drive the car around at 40 mph for a while to relearn the settings. At first the car will idle very high as the IACs relearn the correct position. You may want to remove them and clean the pintle (brass part that does the actual air-flow constricting). It's not hard to do. Do it before you reset them.
Also, if this doesn't fix the problem check the fuel pressure. Nothing screws with a crossfire as much as erratic fuel pressure.
Also, if this doesn't fix the problem check the fuel pressure. Nothing screws with a crossfire as much as erratic fuel pressure.
Thread Starter
Racer
Joined: Apr 2005
Posts: 435
Likes: 1
From: Worth IL
Well Guy's,
took her to Auto Zone got her scanned and
she threw code 45 and code 33 !!
I changed the m.a.p. sensor and tried to
change the 02 sensor but it's real hard to
take off!! so I soaked it with W.D 40 and
I will try tomorrow, then I'll let you guy's
know if that fixed the problem???
took her to Auto Zone got her scanned and
she threw code 45 and code 33 !!
I changed the m.a.p. sensor and tried to
change the 02 sensor but it's real hard to
take off!! so I soaked it with W.D 40 and
I will try tomorrow, then I'll let you guy's
know if that fixed the problem???
Thread Starter
Racer
Joined: Apr 2005
Posts: 435
Likes: 1
From: Worth IL
Well Guy's
this morning I had some time to finish fixing the problem
I had with my 84.
I installed both the map & 02 sensor's and then started her up
and the darn check engine was still on
so I go back
under the hood to check the vacuum hoses and "lo & behold"
there was a loose hose !!! so in asscence I didn't need
both sensor's, but I figured I might as well leave them on
as the old one's were probably the original one's!
now she is running better then before.
Thanks to you all for your advice.....Poncho
this morning I had some time to finish fixing the problem
I had with my 84.
I installed both the map & 02 sensor's and then started her up
and the darn check engine was still on
so I go backunder the hood to check the vacuum hoses and "lo & behold"
there was a loose hose !!! so in asscence I didn't need
both sensor's, but I figured I might as well leave them on
as the old one's were probably the original one's!
now she is running better then before.
Thanks to you all for your advice.....Poncho
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Sounds good Poncho, glad it's running better.
I would like more feedback on the IAC's on a 84 Corvette throwing a code. I didn't think they do, but JLeatherman says they do. I haven't seen any proof of this. I know on the later than 84 model C4's there is no code for the IAC. Anyone with a 84 Corvette know the truth?
I would like more feedback on the IAC's on a 84 Corvette throwing a code. I didn't think they do, but JLeatherman says they do. I haven't seen any proof of this. I know on the later than 84 model C4's there is no code for the IAC. Anyone with a 84 Corvette know the truth?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Originally Posted by RRT vette
I would like more feedback on the IAC's on a 84 Corvette throwing a code. I didn't think they do, but JLeatherman says they do. I haven't seen any proof of this. I know on the later than 84 model C4's there is no code for the IAC. Anyone with a 84 Corvette know the truth?
Originally Posted by CFI-EFI
No. None of the EFI systems I am aware if can get a code from the IAC. The IAC is merely a slave to the commands of the ECM. It provides no sensor information or feedback to the ECM.
