i have 1 94 4x4 s-10(rounded style) with a 4.3. i parked it for to months. i put in a new fuel pump, and an i.a.c (idle air controler). the problem is it idles ok, but when i hit the gas it bogs, then the goes alitte, then bogs, and usually dies. could this be bad gas. anyone have any idea? please help.jamie

i now you guyss have looked. say somting. at least an i dea.

i have to have this truck runnig by the end of this month, becouse i am going up north, and off roading her. this is a pic.
http://i7.photobucket.com/albums/y291/ford-six/100_0175.jpg

Try changing the fuel filter.

make sure the EGR and the catalytic converter arent clogged. I also had to replace the distributor in an S10 cuz the inards flew apart, I was checkin the ignition module, pulled the cap, and the pieces fell out!

I have a `95 S-10 Blazer with the 4.3 engine. It started running rough and the shop here grabbed a long 3/8 drive extension and tapped on the EGR valve while the engine was running. After a few hits, the engine smoothed right out. It turns out there were pieces of carbon holding the valve open, which causes the rough running.
To fix it permanently, go to NAPA and ask for the Tomco screened EGR gasket. Install it after a little cleaning of the EGR orifices, and it should clear it up. It worked for me and is still running smooth after 20,000 miles

i put a radio, in one of these once, and after the install, it ran like crap, i know a radio shouldn't cause a problem, but somehow, we caused a power flux or something to that nature, took it to a 76 station, he plugged into a code box under the dash, said the codes were off, reset them, and the truck ran like new. sorry, best i can do, wish i could be more precise, but it's all i got...

There are no little critters that maybe made a home in the airbox is there? Try unbolting the airbox and run around the block to see if that helps.

Obviously, if you put a new fuel pump in, there was a problem to begin with?? Maybe it is the fuel pressure regulator?

Do you have a check engine light on. I also had a piece of carbon in my egr valve holding it open. It happens every so often. Guess I'm headed to napa for a screen.

thanks for all your help. i was all fired up to get it going, and then i had to have the front end rebuilt. one plug wire was loose i belive. it will not pop on, and i now know keeps falling off. now it run smooth, but lacks power. when floored there is no power, and the tach jumps alittle.could this be caused by a plug being fowled out(do to driving it with a plug wire loose/ possably off)?
thanks
jamie

Just a week and half ago I cleaned the throttle body on my 4.3. It's a 1990 model - not a Vortech type. Anyway, it was quite simple to buy a repair/gasket kit ($26) and remove the TB. Real simple to pop off the two fuel injectors - follow the instructions in the kit - and soak them overnight. I used a mixture of Seafoam and fuel injector cleaner and immersed them. Then took a toothbrush to the nozzle on them. After putting it all back together, it fired right up and ran very good. Now I can see the fuel spray patterns, it's cool to watch on this TB set up. Maybe that's all you need to do to get rid of the hesitation?? Tom

Just a week and half ago I cleaned the throttle body on my 4.3. It's a 1990 model - not a Vortech type. Anyway, it was quite simple to buy a repair/gasket kit ($26) and remove the TB. Real simple to pop off the two fuel injectors - follow the instructions in the kit - and soak them overnight. I used a mixture of Seafoam and fuel injector cleaner and immersed them. Then took a toothbrush to the nozzle on them. After putting it all back together, it fired right up and ran very good. Now I can see the fuel spray patterns, it's cool to watch on this TB set up. Maybe that's all you need to do to get rid of the hesitation?? Tom

i will try this. my air cleaner was caked in mud. i do not think this is good. thanks.

Is your 4.3 a TBI or CPI? I've got a 92 CPI and I replaced my intake with one off a 94. I used my IAC from my 92 and it caused the motor to not idle. The IAC's are different from 92-94 even though they look similar. Make sure they gave you the one for a 94.

Just a suggestion, I would run some "Sea Foam" through it, I would drizzle it down threw my pvc hose slow not to stall the engine, give it some gas while doing it. This would keep it clean they love th build up with carbon. You will also get a lot of smoke out of the tailpipe while doing this, usually I put a half a can through and the rest into the gas tank. I found Sea Foam to be the best.

Have you changed the fuel filter? Checked fuel pressure?

Not sure what type of air sensor that uses - but if the air cleaner was caked in mud, might also have a bad sensor now.

Is your 4.3 a TBI or CPI? I've got a 92 CPI and I replaced my intake with one off a 94. I used my IAC from my 92 and it caused the motor to not idle. The IAC's are different from 92-94 even though they look similar. Make sure they gave you the one for a 94.

mine is TBI. look the same to me. mine is idling fine. it just when floored the tach goes to 4,500, and the truck goes no faster.

this seafoam stuff i have heard so much about i am going to use it. i just want to see all of the smoke.

i have chaned the fuel filter. the center of it was fopping around i there. the fel presure seems ok. i looked in the manual, and it is with in the specs.

Not sure what type of air sensor that uses - but if the air cleaner was caked in mud, might also have a bad sensor now.

i replaced the iac sensor is that the one?

Not sure which sensor, just thought it/they might be caked also.

So - the truck goes up to 4500rpm's, then just goes flat?

If so, I'd check for a plugged exhaust as mentioned earlier. Could be an easy (but loud) test - disconnect or cut the pipe before the cat & drive it. You could use a band clamp to seal it up again cheap if that's NOT the problem.

Not sure which sensor, just thought it/they might be caked also.

So - the truck goes up to 4500rpm's, then just goes flat?

If so, I'd check for a plugged exhaust as mentioned earlier. Could be an easy (but loud) test - disconnect or cut the pipe before the cat & drive it. You could use a band clamp to seal it up again cheap if that's NOT the problem.

it seems to be getting worse. now the rpms go to 3500rpms when it down shifts. i have no cat, but i dis conected the exhuast from th manifols. did not seem to help, and i got pulled over. i was let off with a warning. today was my day off. so i gave it a tune up. 2 plugs were loose, and the cap and rotor looked pretty bad. i have not drove it yet, but i hope this works. thanks for the help.
jamie

Try on this message board.
http://www.s10forum.com/

Well, shame on us - the FIRST thing you should do is the basics - including a tune-up - when it's not running right. If that doesn't work, then you start with the other things. I assumed you'd already done the tuneup....

These trucks have a common problem with the fuel injector "spider" assembly. Look down the TBI and see if there is any buildup of carbon. Good indication of the spider assembly needing to be replaced.

These trucks have a common problem with the fuel injector "spider" assembly. Look down the TBI and see if there is any buildup of carbon. Good indication of the spider assembly needing to be replaced.

it has black/carbon down there. i had thouhht about changing it. i am now thinking of taking it in. i will try the "spider" assembaly.
thanks
jamie

http://i7.photobucket.com/albums/y291/ford-six/100_0175.jpg

That truck NEEDS a 350. :p

If I remember right, when I replaced that injector spider on my '94 CPI it was around $450, just to give you an idea. I too went through several headaches before I got rid of it. The pickup actually sat at the dealer once for a month and a half, and they needed to have some of the big regional techs that work for GM to come down from the Twin Cities or something in the end. I think I did a spider assembly, MAP sensor, top-end distributor tune-up, plugs/wires, oxygen sensor, convertor gutting, and I forgot what else, in a 3 month span. One time I was having issues I found that a plug wire was arcing off of some metal, and replacing the wire made a big difference. These engines can be VERY finnicky!

Just an FYI, on my '97 S-10 4.3 V6 I took it to the dealer about two years ago because the truck ran very rough (codes for no fire to two cylinders were being thrown) after I resealed the intake manifold. The dealer replaced the fuel injection spider assembly UNDER Warranty. Said it has a 10yr/200,000 mile warranty. At the time, the truck had 150,xxx miles. This truck was never covered by an extended warranty either.