Crossfire Help Needed
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
Crossfire Help Needed
Can anyone explain to me how the IAC motors work & adjustment procedure. I don't want to spend $150 on new motors if not needed. If I put the ECM in diagnostic mode, the motors will move back and fourth. They will not reset after driving over 40. They are driving me crazy. I have installed a new ECM, 02 sensor, & a new CTS.
I don't know what else to do.
Help
I don't know what else to do.
Help
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Can anyone explain to me how the IAC motors work & adjustment procedure. I don't want to spend $150 on new motors if not needed. If I put the ECM in diagnostic mode, the motors will move back and fourth. They will not reset after driving over 40. They are driving me crazy. I have installed a new ECM, 02 sensor, & a new CTS.
I don't know what else to do.
Help
I don't know what else to do.
Help
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
I just replaced the 2 IAC motors. As I suspected they did not help. Yes they will move in & out in the diagnostic mode, but it seem that when the car gets hotter they don't readjust themselves. I seems like when the car gets hot, it's starving for gas. But with the IAC motors fully open that would happen.
I'm going to make up a gauge to check fuel pressure to eliminate that. It just runs to good cold to confirm that is the problem.
I also have ordered an ALDL cable for Win ALDL to see what's going on.
I'm going to make up a gauge to check fuel pressure to eliminate that. It just runs to good cold to confirm that is the problem.
I also have ordered an ALDL cable for Win ALDL to see what's going on.
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
Another update,
Made some progress. I changed back to the 6026 computer to see if it would reset the IAC motors and it responded. When I got home I removed the air cleaner and I could finally see 1 of the pintles thru the IAC port. The manager at O'Reillys played with 1 of the motors. Could he possibly damaged it? The engine was running very flat, like 1 side of the motor wasn't getting enough fuel. The car still runs like ****, but progress. After stumbling home with a full tank of gas I proved 2 things.
1 is wasn't the fuel pickup, but it was very close. It looks like the fuel pump might be failing. I hooked up a gauge and I'm only getting 8 #'s at idle. I had a fuel gage port installed on the TBI's while they were off. If I'm reading off of the front TB, I think the fuel pressure is set on the rear TB. Could this be an adjustment issue, or is the fuel pumps failing.
2. The reman ECM looks like its got some type of problem. The 84 ( 6026 ) ECM seems to be working better.
We are getting closer to the problem, and the money pit is getting deeper!
Made some progress. I changed back to the 6026 computer to see if it would reset the IAC motors and it responded. When I got home I removed the air cleaner and I could finally see 1 of the pintles thru the IAC port. The manager at O'Reillys played with 1 of the motors. Could he possibly damaged it? The engine was running very flat, like 1 side of the motor wasn't getting enough fuel. The car still runs like ****, but progress. After stumbling home with a full tank of gas I proved 2 things.
1 is wasn't the fuel pickup, but it was very close. It looks like the fuel pump might be failing. I hooked up a gauge and I'm only getting 8 #'s at idle. I had a fuel gage port installed on the TBI's while they were off. If I'm reading off of the front TB, I think the fuel pressure is set on the rear TB. Could this be an adjustment issue, or is the fuel pumps failing.
2. The reman ECM looks like its got some type of problem. The 84 ( 6026 ) ECM seems to be working better.
We are getting closer to the problem, and the money pit is getting deeper!
Le Mans Master
Joined: Jul 2000
Posts: 6,663
Likes: 162
From: columbia city in
http://http://www.crossfire.homeip.net/cftest/i dont know if you have found this web site,but this is where i go .change the fuel pump ,its not hard to do it pulls out the top .
Racer
Joined: Jul 2005
Posts: 412
Likes: 1
From: Champlain New York
As a heads up...if you are talking about an 82 Crossfire...installing the 85 Vette TPI fuel pump will increase the pressure and bolts right in.
If your 82 is stumbling from a start...could be a bad fuel pump...the first TBI gets sufficient pressure...but the the downsteam TBI only get leftovers!
What is your fuel pressure now?
Just re-read your post about 8lbs at idle..I think you need around 13lb if I'm not mistaken...get the TPI fuel pump! ( 1985 Vette Delco with new sock and you'll be very happy)
If your 82 is stumbling from a start...could be a bad fuel pump...the first TBI gets sufficient pressure...but the the downsteam TBI only get leftovers!
What is your fuel pressure now?
Just re-read your post about 8lbs at idle..I think you need around 13lb if I'm not mistaken...get the TPI fuel pump! ( 1985 Vette Delco with new sock and you'll be very happy)
Last edited by 33Chevy; Jun 3, 2008 at 08:54 PM.
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Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
http://http://www.crossfire.homeip.net/cftest/i dont know if you have found this web site,but this is where i go .change the fuel pump ,its not hard to do it pulls out the top .
I want to make sure that it's a fuel pump 1st. I'm hoping it might be just an adjustment affecting the passenger side. Just my luck it's the fuel pump. At this rate I ought to have a lifetime warranty on this car from new parts.
Thanks for the help
Racer
Joined: Jul 2005
Posts: 412
Likes: 1
From: Champlain New York
For your info only...I have an 82...sounds like you have a fuel pressure problem. If you wind up installing a new pump..."do some research"..you'll find out that the 1985 TPI fuel pump in the 82 CF is a great cure!
Le Mans Master
Joined: Jul 2000
Posts: 6,663
Likes: 162
From: columbia city in
i was just at the cross-fire forum .yes they had a couple that dis agreed .i think you will have that, and sometimes that can be good .as long as they are respectful to each other .the old forum is starting up another better forum .check back in lots of good help there .get that new pump in and tell us all is good .
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
I will be the 1st to yell out it's fixed. It's been a long hard year on this car. It's alway something, but I would like to see the light at the end of the tunnel.
Whats the deal on changing forums overthere?
Whats the deal on changing forums overthere?
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
There is one thing you should check first. There is a soft rubber connection on the fuel pump. It is notorious for leaking. This causes pressure problems. They usually show up as the fuel gets lower in the tank below that level. Replace that rubber hose connection.
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.
Update,
I changed the fuel pump today based on 8 lbs. of pressure. I went ahead and converted to the 85 model pump that provides more pressure. Not to bad of a job, it took about 2 hours. I took my time not to screw up anything. Hit the key and 12 lbs. of pressure. That was a good sign, meaning I didn't waste another 70 bucks.
I pulled out the IAC again & reset them both to 11/8". After doing that I could see both pintals in the IAC paasage. I drove the car about 5 miles without the motor trying to shutdown. That was a relief. I will check the pintals again after the engine cools down to see if the IAC motors reset.
Thanks for all of the help!
I changed the fuel pump today based on 8 lbs. of pressure. I went ahead and converted to the 85 model pump that provides more pressure. Not to bad of a job, it took about 2 hours. I took my time not to screw up anything. Hit the key and 12 lbs. of pressure. That was a good sign, meaning I didn't waste another 70 bucks.
I pulled out the IAC again & reset them both to 11/8". After doing that I could see both pintals in the IAC paasage. I drove the car about 5 miles without the motor trying to shutdown. That was a relief. I will check the pintals again after the engine cools down to see if the IAC motors reset.
Thanks for all of the help!
the owner of the cross-fire forum wants to make a better web site .all info is posted .
Thread Starter
Racer
Joined: May 2007
Posts: 285
Likes: 0
From: Ga.