carb question on 351
fordforlife
07-18-2004, 03:33 AM
i have a stock 351, and after rebuilding the carb, it runs better, except when you give it gas hard, it almost or does kill it, but if you apply it slowly, its fine. Someone was telling me it might be the front pump deal. (where the throttle pushes the pump in to pump the gas in the first bowl) It has a vacuum secondary. any help is appreciated. thx!
fordforlife
07-18-2004, 09:08 PM
the pump has a threaded screw that hits the pumps arm. The screw has a spring on it, which is held on by a nut. which way would i turn it to decrese the amount of fuel being sent into the first bowl?
duplox
07-19-2004, 01:07 AM
Did it do this before you rebuilt the carb? If not, then there is nothing wrong with the carb. There are two things that will judge how big the shot is - the size of the jet you use(screw in above the venturi) and the size of the pump that you use in the accellerator. I think you can get a 30cc pump and a 50cc or somethign like that. You probably have 30. The problem I'm hearing is you arent getting enough shot. Either this is because your accellerator linkage is too lose and right when you crack the throttle it isn't getting any extra fuel, so it'll bog very bad. But it would be very difficult to get the car to move at all. I had this problem on my car and I had to baby the gas just so it would move. I think you have your linkage set too tight, so the pump is already being somewhat depressed with your foot off the gas. Either way, here is how to fix it:
Adjust the linkage so its loose, so the screw head is not touching the lever that pushes the pump. Now slowly adjust it back so it comes closer to the lever, until it just barely touches, it shouldn't be pushing the lever at all but it should be touching it. That should cure your problem.
Adjust the linkage so its loose, so the screw head is not touching the lever that pushes the pump. Now slowly adjust it back so it comes closer to the lever, until it just barely touches, it shouldn't be pushing the lever at all but it should be touching it. That should cure your problem.
motor_head_429
07-19-2004, 04:23 AM
What jets do you have?
fordforlife
07-19-2004, 04:10 PM
it had 68's and the guy that helped me rebuild it (basically went back through it when i was done) said it should have 66's, so we put those in there. im gonna go check the throttle linkage, im not sure if its tight or loose, i hadnt thought of that.------- The car will run and drive, but it struggles up hills, cuz i have to give it more throttle, and it wont get out in traffic, lol. But around the block its fine. It just smokes. When its idling, it is black at tailpipe, but then looks grey and even white when it gathers (usually in my driveway or rearview mirror). When i get on it hard, a big puff of wither grey or black smoke comes out. It doesnt smoke when you first crank it up though, just after it warms up. Then it doesnt stop. thx!!! any other questions, let me know. by the way, i had orangish redish fire at the plugs, so i changed cap, rotor, plugs, wires, coil, and brainbox. it helped the smoke a good bit, but didnt fix it.
351wStang
07-20-2004, 12:43 AM
You are running way to rich.
fordforlife
07-20-2004, 01:26 PM
so how do i fix it?
Rod&Custom
07-20-2004, 04:38 PM
Carbs are tricky, and even though you may have thought you cleaned it out good, it still may have a few clogged passages. Thats what it sounds like to me. I suggest getting a good carb cleaner, and either have someone take it apart and clean it REALLY GOOD, or you do it yourself. I use a thin gauge wire, and good carb cleaner, and the carb will run like new. Don't forget though that new isn't always perfect. After its clean, do ALOT of tuning until it is just right, then see how that smoke is going. Hope this helps.
fordforlife
07-20-2004, 05:33 PM
i soaked it and cleaned it, then a guy behind me soaked it, blew it out with carb cleaner and compressor, and checked everything, so. how do i tell if it is the original carb or the correct one. I called ford and they said they didnt know. the #'s on the air horn are........9834-3 and then right below that # is.......3242 mainly what cfm and jet sizes it needs, stuff like that. thx for all ya'lls help!!!!
fordforlife
07-20-2004, 05:35 PM
by the way, it didnt have the plate that goes on the rear of the carb, the little metal plate that sits between a gasket and the larger metal plate, where a metering plate would go if it had rear jets. i'll try to find the correct name for them asap.
fordforlife
07-20-2004, 05:38 PM
the secondary metering body plate is what was missing when i took the carb apart. it sits behind the secondary metering plate. thats what i was trying to describe in the previous post.
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