Carb Issues - PLEASE HELP

[74 Shortbed]

If you paid him to make it run right, then take it back and make him make it right that's what you paid for. It would be in your best interest though to take some time and learn how a carb works, so in the future you can save yourself a lot of grief and money, not to mention having the satisfaction of doing it yourself..

 

[1987_chevy_]

If you paid him to make it run right, then take it back and make him make it right that's what you paid for. It would be in your best interest though to take some time and learn how a carb works, so in the future you can save yourself a lot of grief and money, not to mention having the satisfaction of doing it yourself..

Yes, I agree with you! I just don't have time to mess around with something that I need to drive everyday, you know? If I had another vehicle I would figure out how to do!

 

[gpmorgan]

That's the main reason I work on my own junk. Don't have time or really trust other people's work.

 

[1987_chevy_]

That's the main reason I work on my own junk. Don't have time or really trust other people's work.

If I could do it, i would I'm young and I don't know much

 

[gpmorgan]

There is lots of detailed info of your issues on ytube. I've was a mechanic for 25 plus years and I still rely on it at times.

 

[74 Shortbed]

If I could do it, i would I'm young and I don't know much

But now is the time to learn, I wasn't born with knowledge flowing out my ass either, lol, took a lot of years to learn this stuff, and ya know what I still don't know **** because I still learn something new everyday, and I look forward to it too. You guys have no idea how lucky you are to have all this knowledge just sitting on your lap to absorb..

 

[tanyourhide]

I chase this kind of problem of stalling at lights on 250 inline 6. Make sure the carb is bolted down tight enough or at least chexk for cachum leaks. Mine had had a big vac leak at base of carb and hasnt stalled aince

 

[1987 GMC Jimmy]

I chase this kind of problem of stalling at lights on 250 inline 6. Make sure the carb is bolted down tight enough or at least chexk for cachum leaks. Mine had had a big vac leak at base of carb and hasnt stalled aince

Yeah, that can cause a lot of problems. If you do tighten it, make sure to do it in a criss cross pattern and don't overtighten.

 

[LuvNLife]

Is there any way you can post a picture of the carb or the spec sheet that came with it? That eliminates some guesswork on this end. Also, you mention Quick Fuel recommending an idle of 1500-2000RPM. That would be the idle with a choke engaged, not your warmed-up idle.

 

[Fixer upper guy]

Go buy a carter 750 with electric choke from summit bolt it on. Set the choke and idle mixture. Check your fuel pressure by installing a tee with ball valve on it and a legnth of fuel hose long enough to clear the engine bay and run into a gas can. Start the engine and run it up to 3500rpm and open the ball valve untill the pressure starts to fall on your gauge and the engine starts to stumble run fall off. Next close it until the difference between fully closed and ware it is set is 1/2 psi. Then put the engine down to idle if the internal pressure regulator is working the pressure shouldn't rise or fall from that point more than 1/2 psi. That's assuming that you have a mechanical fuel pump with internal regulator.

 

[RustyPile]

He means mechanical secondaries. Looks like a Holley 4150 650 cfm.
https://www.summitracing.com/parts/...MIoae0wLmA1wIVxCSGCh2uAQp2EAQYASABEgJh7fD_BwE

87chevy, we need to know exactly what carburetor you have, can you provide that information??.. The one in the link is TOTALLY not for the street. It has no provisions for a choke, no power valve - a plug instead, jetted way to big, and finally, it has mechanical secondaries.. It's a race carburetor and when installed on a stock or near stock low rpm engine, it will exhibit every problem you're experiencing..

A choke greatly aids cold engine run. It's a method to enrichen (less air, more fuel) the fuel/air while the engine warms up. A power valve aids fuel metering under part throttle conditions and helps the engine handle varying load conditions. Vacuum operated secondaries allows the engine to "choose" the rate at which the secondaries open.. All these qualities are necessary for the operation of a street engine, but none of which are desirable in a full race engine..

If your camshaft is one of moderate to extreme duration, due to diminished manifold vacuum, you'll experience some drivability issues that you'll have to learn to live with.. The greater the engine displacement, the more tolerant the engine is of "long" duration cams.. Put a cam in a 265 - 283 cid old Chevy that gives it a lumpy rumble.. Take that same cam and put it in a 383 - 400 cid engine and it will be almost silky smooth..... This explains why you can put a wild ass cam in a big block built for the street, and it's just a big ol' ***** cat....

87Chevy, I sincerely hope this helps you..

 

[crazy4offroad]

87chevy, we need to know exactly what carburetor you have, can you provide that information??.. The one in the link is TOTALLY not for the street. It has no provisions for a choke, no power valve - a plug instead, jetted way to big, and finally, it has mechanical secondaries.. It's a race carburetor and when installed on a stock or near stock low rpm engine, it will exhibit every problem you're experiencing..

A choke greatly aids cold engine run. It's a method to enrichen (less air, more fuel) the fuel/air while the engine warms up. A power valve aids fuel metering under part throttle conditions and helps the engine handle varying load conditions. Vacuum operated secondaries allows the engine to "choose" the rate at which the secondaries open.. All these qualities are necessary for the operation of a street engine, but none of which are desirable in a full race engine..

If your camshaft is one of moderate to extreme duration, due to diminished manifold vacuum, you'll experience some drivability issues that you'll have to learn to live with.. The greater the engine displacement, the more tolerant the engine is of "long" duration cams.. Put a cam in a 265 - 283 cid old Chevy that gives it a lumpy rumble.. Take that same cam and put it in a 383 - 400 cid engine and it will be almost silky smooth..... This explains why you can put a wild ass cam in a big block built for the street, and it's just a big ol' ***** cat....

87Chevy, I sincerely hope this helps you..

I think you quoted the wrong post

 

[OkieFishMan]

If I could do it, i would I'm young and I don't know much

Hop on youtube and search for your model of carb. You should be able to find a wealth of information online, and you will be pleasantly surprised how much you can learn by investing a few hours watching videos and reading articles.

As for getting help from us here on the forum, we need to know what your are working with. A lot of guys here can give great advice, but we have to know things like carb model, cam specs, fuel supply (like mechanical or electric), etc. The more information you provide the better the answer will be.

 

[RustyPile]

I think you quoted the wrong post

Curt, No I didn't.. My post was addressed to 87Chevy, but I quoted your post, not to direct my reply to you, but to address the item of the link you posted.. I know you weren't recommending (at least I hope you weren't) that carburetor to the OP.. I wanted to explain the reason the carb in the link was the wrong carb for his application....

Sorry if I offended you.. That was not my intention..

 

[crazy4offroad]

I just googled the brand and that was the first thing that popprf up, it wasn't my recommendation.