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Hi all;
The project ride has hit the road and now I am trying to work out the bugs. As a little background, the truck is a Pre-EGR 350 V8 with a T350 transmission.
When I bought it it didn’t run so well and would just about quit when I pulled up to stop lights. Its been a lot of work later, and that issue even got resolved for a bit, but now I am seeing something similar again, making me think I’ve overlooked something. So to list I.
1) put on a Professionally rebuilt Carb (bought new to me Rochester Quadrajet like the one it had)
2) new base gasket
3) new Vac advance line to Carb
4) new fuel filter in the line(plug, wires, Distributor cap and rotor were done last year just before buying)
This is where its sat for the winter till I got at it again this spring. When I started it I noticed the idle was pretty high so released the idle screw some. This helped a bit but it was still running a bit high. I lubricated the linkage and replaced the throttle spring and it seemed a lot better after that.
Then I took it for a good 30 min drive or so to see how it would do on the highway. I got it up to about 50 miles an hour for about 10 minutes and then took it around the city drive for another 20 minutes. She wasn’t running the greatest that last 15 min. Like I wasn’t getting much power. It almost seemed to be missing maybe. It was lightly raining too. I notice the miss when I let off on the throttle not so much when accelerate
Well after doing so research, I decided since it was 25 dollars, I replaced the fuel pump today as the one on it looked pretty old. I find the throttle response is really good now. No miss or hesitation there at all when reving (from under the hood)
So I took it for a run around the block to see how things would do and wow, the miss was really bad. Its warm out here (like 10C /50F) so no choke needed. Truck never quit on me but it felt like it could have, I got it home and it was sputtering and missing.
I looked under the hood ad the choke was half shut trying to run. When I cut the engine I even saw some gas leaking out from the side of the carb. That explained it a bit so pulled the choke wide open manually, I tinkered for 5 minutes looking at anything else it could be and then fired it up again
This time the thing started right up. Idles fine, no miss not sputters, no smoke at the back end. works and revs great. THEN after about 2 minutes of idle, the truck slows idle suddenly almost down to a chug. I hit the gas to keep it going. The choke is forced wide open. And I’m like WHAT THE HECK?
I grab some carb cleaner and start spraying the base of the carb, the carb itself, all my linkages, all my air hoses, the hose to the brake cable, nothing, the idle never changes. Then this once I spray the air hose where it attaches at the brake booster and it seems to speed right up. I think I find it! But then it goes back again. I spray some more, nothing, I soak the thing then, nothing. I shut the truck off again. Let sit 5 minutes, Fire it up and idles fine for a couple minutes then chugs down again, I spray the booster hose again and this time it does nothing. I rev the engine and get it back into high idle again. I move that bake booster hose all over the place and it does;t seem to cause a thing with the idle. I leave engine alone and a minute later it goes back down to chugging again.
Anyway, the gas tank is behind the seat with no rust in it, there is a new fuel pump and filter in the carb, and a fresh rebuild on the carb from last year.
Then main thing I had bee trying to avoid too was I kept needing to pour gas down the carb to get it to start every morning
(note that since the rebuild I have only had to do this like 10 times. 3 over the winter and the last 7 times I drove it) If I start it once during the day, the rest of the day it generally fires right up. Trying to fix this issue I have now have an idle issue.
Any thoughts as to what the heck this could be? I called it a night. I’m head scratching now.
Here is the pickup in question. Thanks again for all you help
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