Engine burping
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Tuned
Joined: Feb 2002
Posts: 441
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From: Vicksburg, MS
Engine burping
I've got a 78 F250 with the 400 in it. For the past 4 years (after I got a new engine), I've had an Edelbrock 750cfm on it. I decided to change to a 600cfm to get some better mileage and improve daily driveability, so I put the Edelbrock version on.
When the truck is cold, and I'm trying to accelerate at light throttle, it burps out into the headers and loses power, but it doesn't backfire out of the exhaust pipes. If I give it more gas and try to accelerate at medium (or higher) throttle, it seems to bypass the problem and doesn't do it.
I have an air/fuel meter (the cheap variety with the lighted bars), and it's showing a slight rich condition, which is what it shows at cruise. So, that seems fine.
Any ideas?
When the truck is cold, and I'm trying to accelerate at light throttle, it burps out into the headers and loses power, but it doesn't backfire out of the exhaust pipes. If I give it more gas and try to accelerate at medium (or higher) throttle, it seems to bypass the problem and doesn't do it.
I have an air/fuel meter (the cheap variety with the lighted bars), and it's showing a slight rich condition, which is what it shows at cruise. So, that seems fine.
Any ideas?
Thread Starter
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Tuned
Joined: Feb 2002
Posts: 441
Likes: 0
From: Vicksburg, MS
The pump linkage has 3 holes, and I moved it to the more "rich" hole, and it doesn't do it as much, but still does until the engine heats up.
I checked the fuel pressure, and it's about 5 psi. I think Edelbrock recommends 5-6 for those carbs. Could that be a problem?
The truck cranks up fast and runs great otherwise, so I'm pretty confused.
I checked the fuel pressure, and it's about 5 psi. I think Edelbrock recommends 5-6 for those carbs. Could that be a problem?
The truck cranks up fast and runs great otherwise, so I'm pretty confused.
Posting Guru
Joined: Mar 2007
Posts: 1,191
Likes: 1
It kind of sounds like you distributer isnt advanceing. If you have vacuum advance, make sure it is functioning properly, if you have weights to, check them....
Keep in mind, a rich mixture, when hitting cold air, may rumble a bit, or pop even.
Keep in mind, a rich mixture, when hitting cold air, may rumble a bit, or pop even.
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