#1072471 - 11/12/21 08:36 PM
won’t idle/ running lean.
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Joined: Jan 2005
Posts: 161
8T7AERO
15+ Year
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15+ Year
Member
Joined: Jan 2005
Posts: 161
Corona, CA
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Hi I was out driving my car and made a few quick stops last weekend, after the last one I started the car and she wouldn’t idle, had to keep my foot on the gas to keep from stalling and it also started to miss when driving back home. Got home and let it sit for awhile, started it back up ( which it’s start right up) Checked for vacuum leaks, loose spark plug wire etc, but it wouldn’t idle below 1500 rpm or It would stall. I then noticed the driver side headers were glowing bright red !!!! Turned it off at that point, the temp never went over 180 and the fans were coming on also. Today I started it up and idled fine till the motor warmed up and then she wouldn’t idle again and the headers were starting to glow red again which I think means a lean condition. The carb Is a Holley 750 ultra pumper. Also running 101 unleaded gas.
87 Aerocoupe, Rapp Racing 383 with AFR aluminum heads.Leather interior,Hedman headers,Flowmaster Super 40's, k&n filter,MSD Ing, 17x8 IROC w/ 245/45/17, Wilwood front & rear disc brakes, UMI Performance Stage 2.5 suspension,8.5 GN 4.11 posi rearend, Viking coilovers, Kenwood sound system..
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#1072473 - 11/12/21 09:58 PM
Re: won’t idle/ running lean.
[Re: 8T7AERO]
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Joined: May 2007
Posts: 5,130
Buick Runner
10+ Year
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10+ Year
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Joined: May 2007
Posts: 5,130
Dharma station 1 the Hydra
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Vacuum leaks, probably gets worse as the parts expand from heat. Probably a vacuum leak on the driver's side of the intake manifold.
SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.
2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes, and Jmod.
Never argue with an idiot. They will just drag you down to their level and beat you with experience.
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#1072539 - 11/21/21 07:50 PM
Re: won’t idle/ running lean.
[Re: Buick Runner]
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Joined: Jan 2005
Posts: 161
8T7AERO
15+ Year
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15+ Year
Member
Joined: Jan 2005
Posts: 161
Corona, CA
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Hi Buick Runner, I tried to check for vacuum leaks using the carb cleaner way, with a cold and warm engine, sprayed around the heads/intake area, base of carb and vacuums lines which I only have 2 the PVC and the fuel vapor canister hooked up. No increase in RPM’s when i did this method, but i did see the passenger headers glowing RED also and it made a loud backfire out the exhaust this time, do u think the idle circuit in the carb could me blocked? or something else with the carb?
87 Aerocoupe, Rapp Racing 383 with AFR aluminum heads.Leather interior,Hedman headers,Flowmaster Super 40's, k&n filter,MSD Ing, 17x8 IROC w/ 245/45/17, Wilwood front & rear disc brakes, UMI Performance Stage 2.5 suspension,8.5 GN 4.11 posi rearend, Viking coilovers, Kenwood sound system..
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#1072541 - 11/21/21 08:27 PM
Re: won’t idle/ running lean.
[Re: 8T7AERO]
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Joined: May 2007
Posts: 5,130
Buick Runner
10+ Year
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10+ Year
Member

Joined: May 2007
Posts: 5,130
Dharma station 1 the Hydra
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I don't know much about Holleys. I am mostly familar with the stock Qjet. It stills sounds like a bad vacuum leak, try using an unlit propane torch if you can. Are you sure that you are using a vacuum advance dist with your non stock carb? The stock dist is computer controlled and will only work with the stock computer controlled carburetor. Also check your ignition timing as retarded timing can also make an engine run hot.
Last edited by Buick Runner; 11/21/21 08:28 PM.
SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.
2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes, and Jmod.
Never argue with an idiot. They will just drag you down to their level and beat you with experience.
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#1072543 - 11/21/21 09:17 PM
Re: won’t idle/ running lean.
[Re: Buick Runner]
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Joined: Jan 2005
Posts: 161
8T7AERO
15+ Year
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15+ Year
Member
Joined: Jan 2005
Posts: 161
Corona, CA
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I’m using MDS ignition, 6AL box, coil, and non-vacuum MDS dist. p/n 85551. I’ll check the timing, Dist. isn’t loose i checked it and I’ve been driving it for a year with no issues until a few weeks ago. Thanks
87 Aerocoupe, Rapp Racing 383 with AFR aluminum heads.Leather interior,Hedman headers,Flowmaster Super 40's, k&n filter,MSD Ing, 17x8 IROC w/ 245/45/17, Wilwood front & rear disc brakes, UMI Performance Stage 2.5 suspension,8.5 GN 4.11 posi rearend, Viking coilovers, Kenwood sound system..
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#1072729 - 12/14/21 05:56 PM
Re: won’t idle/ running lean.
[Re: BadSS]
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Joined: Jan 2005
Posts: 161
8T7AERO
15+ Year
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15+ Year
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Joined: Jan 2005
Posts: 161
Corona, CA
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Hello, Thanks for all the info, I put a brand new Holley 600 carb on it that I had for another project, It did the same thing, once it warmed up it wouldn’t idle and headers started to glow red ( but not as bright) but it took a little longer to do so. I’m using MDS 8.5mm super conductor wires. I normally run 91 octane unleaded and mix it with 101 octane unleaded about 50/50 but this time I used a more of the 101 octane, this the only thing different I did before I drove it.. My vacuum at idle is 10” do to the cam size. My timing light died on me, when I get my new I’ll check it. Also I’m trying to make up a propane tester. Thx everyone
Last edited by 8T7AERO; 12/14/21 05:57 PM.
87 Aerocoupe, Rapp Racing 383 with AFR aluminum heads.Leather interior,Hedman headers,Flowmaster Super 40's, k&n filter,MSD Ing, 17x8 IROC w/ 245/45/17, Wilwood front & rear disc brakes, UMI Performance Stage 2.5 suspension,8.5 GN 4.11 posi rearend, Viking coilovers, Kenwood sound system..
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#1072863 - 01/05/22 01:10 AM
Re: won’t idle/ running lean.
[Re: tom demarco]
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Joined: Jan 2005
Posts: 161
8T7AERO
15+ Year
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15+ Year
Member
Joined: Jan 2005
Posts: 161
Corona, CA
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Hello, checked my timing and it was set 22 deg. total advance. I retarded the timing and the headers still stayed red. So at this point I figured the intake gasket might be the problem, so I started to disassemble it, put the #1 cylinder at TDC and pulled the distributor cap and seen that the reluctor paddles and magnetic pickup assembly are covered in rust/corrosion. Anybody think this could be cause of the issues ? Thanks
87 Aerocoupe, Rapp Racing 383 with AFR aluminum heads.Leather interior,Hedman headers,Flowmaster Super 40's, k&n filter,MSD Ing, 17x8 IROC w/ 245/45/17, Wilwood front & rear disc brakes, UMI Performance Stage 2.5 suspension,8.5 GN 4.11 posi rearend, Viking coilovers, Kenwood sound system..
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#1073111 - 02/05/22 06:08 PM
Re: won’t idle/ running lean.
[Re: 8T7AERO]
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Joined: Jan 2005
Posts: 161
8T7AERO
15+ Year
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15+ Year
Member
Joined: Jan 2005
Posts: 161
Corona, CA
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Thanks for the help, it was the intake manifold gasket that was the problem.The Monte is up and running. Also the corrosion on the MSD distributor is a know problem with that model according to MSD.
87 Aerocoupe, Rapp Racing 383 with AFR aluminum heads.Leather interior,Hedman headers,Flowmaster Super 40's, k&n filter,MSD Ing, 17x8 IROC w/ 245/45/17, Wilwood front & rear disc brakes, UMI Performance Stage 2.5 suspension,8.5 GN 4.11 posi rearend, Viking coilovers, Kenwood sound system..
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#1073117 - 02/06/22 12:03 AM
Re: won’t idle/ running lean.
[Re: 8T7AERO]
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Joined: May 2007
Posts: 5,130
Buick Runner
10+ Year
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10+ Year
Member

Joined: May 2007
Posts: 5,130
Dharma station 1 the Hydra
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Thanks for the help, it was the intake manifold gasket that was the problem.The Monte is up and running. Also the corrosion on the MSD distributor is a know problem with that model according to MSD. Probably late, but did you check the intake manifold for warpage? I had intake vacuum issues and it turned out the manifold was warped.
SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.
2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes, and Jmod.
Never argue with an idiot. They will just drag you down to their level and beat you with experience.
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