Hard starting when warm
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Instructor
Joined: Aug 2008
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From: Le Roy NY
Hard starting when warm
I've got a 1980 with a 290HP crate motor and RV cam. I rebuilt the Q-jet and the car runs great and starts great when cold. When warm however, it's a bear to fire up. Need to crank with the pedal down for 4-5 seconds. Didn't remember this problem before the rebuild. The rebuild was performed due to leaking gaskets and loose shafts. Any thoughts?
Melting Slicks
Joined: Mar 2007
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From: Hinckley OH
With a carb that's working properly all you should need to do for a warm engine is turn the key. If you are in the habit of giving it gas because it needed rebuilt then you might be flooding it.
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From: Science Bitch! Mississauga, Ontario
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I have the same problem. Car starts easily, but is hard to start after it's hot and I notice that the carb is dripping gas.
I installed a heat shield and a spacer, but the problem persists.
Could the fact that my charcoal canister is hooked up incorrectly or the fact that my fuel return line is not being used?
I installed a heat shield and a spacer, but the problem persists.
Could the fact that my charcoal canister is hooked up incorrectly or the fact that my fuel return line is not being used?
Last edited by AGVI; May 8, 2013 at 09:06 PM.
Thread Starter
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From: Le Roy NY
Good thoughts. I have a high torque mini starter on the engine and have a heat shield blanket around it. I can see cranking speed would be an issue if the starter was overheated. I had this happen before.
I don't see gas dripping other than that from the accelerator pump. I'll check this again. When I rebuild the carb I sealed the plugs as per Cliff Ruggles fine book.
Seems to be excess fuel from somewhere. When holding the pedal down and cranking it starts, but is on the verge of flooding.
I don't see gas dripping other than that from the accelerator pump. I'll check this again. When I rebuild the carb I sealed the plugs as per Cliff Ruggles fine book.
Seems to be excess fuel from somewhere. When holding the pedal down and cranking it starts, but is on the verge of flooding.
Melting Slicks
Joined: Mar 2008
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From: Austin Tx
Another thing to check when having a 'hot start' issue, is the connection of the wire from the starter to the coil. It's purpose is to provide additional power during startups. If this connection is loose or frayed, then the additional heat, will cause additional resistance on this wire, and it will not be able to do it's job.
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Burning Brakes
Joined: Feb 2004
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From: Kearneysville West Virginia
I am having the same issue with my 70. It is not a starter issue, it spins over fine. It is a fuel/flooding issue when hot. I have checked and rechecked the float level. I have looked down inside the carb for fuel dripping, etc., and have seen none. It clearly is loaded up after sitting a few minutes when hot, and it takes some spinning to clear the fuel out before it starts. I am not pushing on the throttle, so that is not the problem. Somehow, fuel is spilling into the intake manifold, but I can not figure out from where.
Le Mans Master
Joined: Jan 2003
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From: Tuttle OK
Cruise-In VIII Veteran
I had a similar issue on a quad. Sent it to Lars and he said that some of the quad castings were porous allowing fuel to drip. That was the case with mine, just something to consider.
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From: Le Roy NY
I'd rather not mess with the timing since that will effect the otherwise good performance. The timing is right where it "should" be according to what Lars and other have taught us. I do not have a fuel return.
I've corresponded with Cliff Ruggles who, very kindly, has replied quickly to my questions. He posits that the plugs might be leaking. I did seal them with epoxy, but of course, used the stuff that works the worse for this application: JB Weld. I'll have to pull the carb and pressure test it for leaks.
As an aside to this, the fuel mileage has dropped off after the rebuild also. Another indication of excess fuel is the inability to lower the idle speed. All things point to a fuel leak.
I've corresponded with Cliff Ruggles who, very kindly, has replied quickly to my questions. He posits that the plugs might be leaking. I did seal them with epoxy, but of course, used the stuff that works the worse for this application: JB Weld. I'll have to pull the carb and pressure test it for leaks.
As an aside to this, the fuel mileage has dropped off after the rebuild also. Another indication of excess fuel is the inability to lower the idle speed. All things point to a fuel leak.
Thread Starter
Instructor
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From: Le Roy NY
Got the engine up to temp yesterday, and took a good look down its throat. Lots of vapor. Am I correct that this indicates either leaking plugs in the Q-Jet or a float set too high?
Burning Brakes
Joined: Nov 2006
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2022 C3 of the Year Finalist - Modified
I had this problem with my both Vettes, the problem was the original starter when he heat up he doesn't want to rotate the engine all the current go on the coils of the starter.
I bought a small high torque starter (sorry it Chinas) install it in my both Vettes and it spin the engine easily when its warm or cold and it cost ~$60.
Avner
I bought a small high torque starter (sorry it Chinas) install it in my both Vettes and it spin the engine easily when its warm or cold and it cost ~$60.
Avner
Le Mans Master
Joined: Jan 2006
Posts: 6,502
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From: Butler Pa
I had this problem with my both Vettes, the problem was the original starter when he heat up he doesn't want to rotate the engine all the current go on the coils of the starter.
I bought a small high torque starter (sorry it Chinas) install it in my both Vettes and it spin the engine easily when its warm or cold and it cost ~$60.
Avner
I bought a small high torque starter (sorry it Chinas) install it in my both Vettes and it spin the engine easily when its warm or cold and it cost ~$60.
Avner
Le Mans Master
Joined: Jan 2006
Posts: 6,502
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From: Butler Pa
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From: Science Bitch! Mississauga, Ontario
Canadian Events Coordinator
Les