Mechanical fuel pumps

[hatzie]

And the springs. OMG, was it this set or that one or did I swap the two into separate groups?

The originals are usually so rusty it's not difficult to tell them from the new ones.
If you get a decent set the spring pairs are different bright colors so you can tell em apart.

I always use a nasty beat up commercial baking sheet with the tall edges and a stained beat up terrycloth dish towel so the springs, screws, etc don't make a break for it.

 

[DavesJimmy]

Put in a new msd hei distributor and new wires. Problem is still there
I slammed the throttle wide open it died and flames where burning out of the carb.. i also noticed that when i disconnected the vacuum advance to set timing i didn't notice a difference in the way it idled.

 

[Rusty Nail]

You have an ignition timing problem Dave, try not to set the Jimmy on fire..

 

[asltrfl]

Did you install your own cam, timing chain and gear set? Might be off if its spitting flames. Slow down, double check TDC with the spark plug out and timing marks on balancer. Double check plug wires for damage or cross firing. Rotor and cap installed correctly? Dont worry, you'll get it right. Walk away and dont worry about it for a while, you will be able to think better when you come back.

 

[HotRodPC]

Did you install your own cam, timing chain and gear set? Might be off if its spitting flames. Slow down, double check TDC with the spark plug out and timing marks on balancer. Double check plug wires for damage or cross firing. Rotor and cap installed correctly? Dont worry, you'll get it right. Walk away and dont worry about it for a while, you will be able to think better when you come back.

This and if you're timing with a light, make sure your balancer hasn't spun. There's at least 2 of us, me being one of them, had balancers that spun and the timing marks were off.

 

[DavesJimmy]

Its a brand new gm 350 crate engine, new balancer. Im going to try some new plugs, check timing again.

 

[Snoots]

No no no no no.

Something ain't right here and we're not getting all the info.

When you got the crate engine, what did you change or add to it after you opened the crate?
You had to go and put in a msd and you didn't know what the problem was?
Like EVERYONE else has said from the get-go, you've got a timing problem.

 

[DavesJimmy]

No no no no no.

Something ain't right here and we're not getting all the info.

When you got the crate engine, what did you change or add to it after you opened the crate?
You had to go and put in a msd and you didn't know what the problem was?
Like EVERYONE else has said from the get-go, you've got a timing problem.

Ok. I bought a gm 350 long block crate engine. All the accessories came off the old engine. Starter, intake, carb, fuel pump, hei, headers, alternator, power steering pump, fan, etc... i did nothing to the engine out of the crate except bolt on all the accessories. Had carb rebuilt and tuned. New msd hei. New msd wires. Timing is set at factory 8° btc @ 550 rpm like my 79 c10. I can get to wot at a steady pace no issues. But i cant mash the gas it boggs, stumbles, and dies. Sometimes it catches up and wont die id i let off quick enough... i think its timing to but unless gm ****** the install of the timing gear and chain i dont know wtf is going on

 

[Snoots]

That's better.

Sounds like you're not getting any advance. From where are you getting the vacuum for the distributor?
OR, there may be a vacuum leak somewhere. A big 'un! Doubtful, but possible.

 

[Blue Ox]

Also, look down the carb (with the engine off) and open the throttle quickly. You should see two solid streams of fuel from the accelerator pump. If your "rebuilt and tuned" carb has an accelerator pump problem it will bog and stall on acceleration.

 

[HotRodPC]

This is certainly a strange problem. It really does at quick first guess sound like an accelerator pump issue at the carb. I wish someone around or near you had a different carb to bolt on just for process of elimination. If you bolted on a KNOWN good carb off of another good running truck, and it cured the problem, then we KNOW it's the carb issue. If it doesn't cure the issue, then we KNOW it's got to be in the ignition system.

 

[HotRodPC]

Also, look down the carb (with the engine off) and open the throttle quickly. You should see two solid streams of fuel from the accelerator pump. If your "rebuilt and tuned" carb has an accelerator pump problem it will bog and stall on acceleration.

Yeah, see you're thinking and responded while I was typing my response. It does sound like an accelerator pump issue.

 

[DavesJimmy]

Well im going to buy the msd atomic efi master kit. And get rid of the carbs!

 

[DavesJimmy]

I was thinking msd atomic efi, or holly, or fitech. Does anyone run any of these and have opinions? They all seem similar but the msd looks like it installs a little easier??

 

[Frankenchevy]

Mine isn’t complete yet, but I did a fair amount of research before going efi and settled on the Holley. I also found when researching, that using an in tank pump is the way to go. It’s more reliable, simpler, and only a couple more hours of work. In my case, it was less work. However, my truck is in 100 pieces, so access is easy.