Hello forum,

I mostly reply to problems rather then posting them.
however this issue has me stumped.

A brief history of what we did..

My step dad and I decided to remove his 2.8l V6 from his s10, and swap it with a 4.3 ltr that was TBI, I removed the TBI and intake replacing it with a 4 brl carb and intake (No Computer).

The starter is from a 3.1 Corissa rebuilt to fit the 4.3, really no issue with starting, however randomly the tuck will die and will not start, I was thinking the starter does not have enough torque to turn the engine, at some time the starter spins the crank with no issue and the engine fires.

the main issue we are having is after the engine has been running and driving, after the engine gets hot the engine looses power and begins to run rough, like if its loosing compression, because metal expands after it becomes hot and contracts when cold.

The carb has an electric choke, however its not wired up, the carb was adjusted and does not seem to fix the issue.

The way we have the engine set up is just like the old days, carb, and block, no computer, and only the hot wire and ground.

any ideas or suggestions would be great.

-Alex

 

when the truck dies and doesn't re-start is when you need to check the spark and fuel.

Could be a failing ignition module, Ignition Coil gets hot and dies

Or a choke issue

The carb should be setup for proper mixture when it's FULLY Warmed Up
inluding having the choke all the way open.

On a side note: the choke needs to be set to when the truck is warm the plate is wide open, you can run a wire through the oil pressure switch so when there's oil pressure it sends 12 to the choke coil. so if you wanted to sit in the car with the key on you wont be supplying 12v to the choke and opening it then having a hard start.

If the engine is turning slowly when it's hot could be bad starter. Make sure your connections on the starter are tight and good cable ends. Same with the NEG to the block.

Might be a good idea, to get a compression gauge and check the engine compression cold and hot to see if there's a difference.

What are you using for a fuel pump ? Too much fuel pressure and you'll be dumping fuel into the engine when its hot, but when it's cold it can take and like more which is the purpose of the choke ( cuts back on the air creating more vacuum, pulling in more fuel )

 

iv seen this on a tv show. i dont remember which one at the moment but, power block comes to mind, the title was 500 horse from a v 6. the motor was gm's early 4.3 although the project was not overly sucsesfull in longevity, it did produce an ungodly source of horsepower. issues were timming and fuel ratio to air. of course they had a dyno machine to help solve there issues. (and new parts)they also replaced the distibutor with a high performance hei distributor due to the (oe) distibutor would not produce the correct timming for perormence.this could be a huge factor in perfomence here is a couple of web sites that may help good luck! http://www.hotrodders.com/forum/4-3-...er-114080.html http://www.msdignition.com/Products/...stributor.aspx