WhAt ElSe Is ThErE!!!!

[livlifes2short]

Hey I am new to the forums here but am in desperate need of your help. Recently purchased a 94 s10 tahoe balzer 4x4 4.3 vortec (w). The problem is when in park or netrual when I rev it up once it gets to a certain rpm it hesitates or missis. Seems like it wants to fall on its face. Does the same thing in drive I can drive it ok but have to very slowly get to cruising speed. Once at cruising speed or at idle you can feel a very minor miss or hesitation ( not something you would notice unless you were looking for it). So this is what has been replaced so far. Oil, Oil filter, Cap, Rotor, Plugs, Wires, Coil, Pcv, Air filter, Fuel filter, Fuel Pump, Fuel pressure regulator (was leaking spider and nut kit looked good), Cat was hollowed out, and took of egr cleaned and replaced with screened gasket. Please help me here I can not throw any more parts at it, what can I test what should I look at next Thanks And Sorry For The Long Post!!

[MT-2500]

Welcome to AF.
Any codes or check engine lights?
Got good hot blue spark to all cylinders?
Fuel pressure up to par?
What is the fuel pressure reading on the road or when it does it?
Have you checked the dist shaft for side play?
Tps sensor good?
Good compression?
Any engine noise?
What brand of spark plugs are you using?

[livlifes2short]

Ok there are no codes. Fuel pressure runs 51ish at idle 55-60 on throttle when it is and isnt doing it under load. Good hot blue spark?? checked spark and all is good if that is what you are reffering to. Dist play.... have not checked that I am assuming I would just be able to move it some? will check that in a few. Some one else reccomended the tps isnt there a way to test this as I have thrown alot of parts at this think? No engine noise they are autolie plugs do not remember specifics but they were the best I could get for this truck. And I dont have a compression tester to test cylinders. THanks

[discnik]

Does it do this before the engine is at operating temp. ?

Have you checked for any leaks around the exhaust manifold gaskets, although that should throw a code but maybe not.

Just some thoughts.

[livlifes2short]

cold and running temp and there was a manifold leak when i got it but that is already fixed no other leaks

[MT-2500]

Is this a W code engine?
Fuel pressure should be checked on the road after 20-30 minutes of running?
Specs are 55/61.

Ac plugs work a lot better.
I would try a set of AC plugs the book calls for.
Check that dist shaft for loseness.
Check the base engine timing.
And make sure you are not losing spark when it does it.
Always check for good hot blue spark to all plugs.
Check compressiuon and engine vacumn at idle and at 2K rpm.
Post back readings.
On TPS check the voltage reading on it to start with.

[livlifes2short]

Ok so after alot of time blood sweat and tears she is fixed!! It was not the spider or the fuel pump or the cat or the egr or a whole list of other things that wont need to be replace on my truck for some time now ( since I just put all that crap in it ) Turns out from the computer I get a good pulse to the injector. Just outside the plenum the reading varies the reading for the actual injector itself puts it into spec. So ends up being the plug for the injector was all messed up so a little love and attention to detail and my project is finally on the road!!!! Thanks for all the great info and assistance through this painful expensive process !!!!

[MT-2500]

You are welcome.
And thanks for posting back how it went and what you found.
Things like that are had to find.
Glad you found it.
Good luck