HI I have a 94 with a 3.4L in it and it starts and runs good in nutral. I take off in the moning and it has good power then when it gets warmed up it bogs.. it just struugles from 1500-5500 rpm.. it seems to have good power up around 7 but the power isnt even at all. I have replaced oxigen sencer,coils,wires,map sencer,fuel filter fuel regulater. tested fuel pressure around 47psi and the engine seems the have some valve train noise. all the plug wires are on right to. I have also replaced egr.. I have tryed takeing the cat out to see it it was pluged and it ran the same way. then when you sitting at a stop sign it will viberate and feel like its missing.. but still run about 800rpm.. im getting very fed up with it.. i have lost races to a 95 beretta a s10 blazer, almost a neon.. I know its a v6 and its not suped to be fast but it should beat some thigs in a race, The drive train and brakes are good and not draging, My last idea is the crank sencer. I also baught the car with a blowen head gasket so I got that all fixed and the heads shaved. could the valve adjustment be off and doing that. I havent compression tested it but i checked cylender 1 and 3 and they were running like 180psi.
any words of advice?

Thanks

 

Did you say your car runs fine when it is cold?
If so, you may want to check the resistance of your fuel injector coils. You may have an injector that is going out of whack and only acts up when the temperature warms up.
Are you getting any coolant in the oil? Are you burning any oil? Are you getting any trouble codes?

 

had a similar problem with my 2.8, turns out the distributor was loose. im not sure you have one though. but still if your timings off a little it may cause the same problem. might also be a slight miss. check your timing thats what i would do

 

I have checked injectors. I baught a set of venom high volume ones and ran them for a week and it did the same thing with tthe new injectors. The oil is clean as can be and so is the coolant. doesnt burn any oil. some times the car back fires throuh the intake. how do you check the timing when u cant even see the balencer?

 

You have DIS instead of a Distributor. I would check your compression and get a vacuum leak check. My car runs like crap until it gets above 180* so I know how you feel.

 

sounds like a coolant temp sensor problem to me!

 

I was going to suggest vaccum lines. I think your 3.4 is a version of my 3.1 - I reccomend spendng the six bucks at autozone for some goodyear silicone ones. My vacuum lines were shot and leaky which caused similar problems. Are you having bad gas mileage or running rich? Also, I'm not engineer, but the vacuum line routing on my 3.1 was RETARDED! I say, keep you vacuum lines away from anything that gets super hot. Coolent temp sensor talks to the computer, so yeah I would replace that, it's only 15 bucks.

 

Oright. I have been getting ok gas milage. Im going to try replacing the water temp sencer but if that was bad why would the temp gauge read right then? And sence its a new car it doesnt have many vacume line but ill chk them all out. I vacume tested it and I think it was a 13.5 or 14 for vacume. Idk about it. Im thinking the cam is wore out or the crank shaft sencer. Ill have to get a temp sencer tomaro and put it in. I have to do a complete compression check yet to. But could it have a bad lifter?

 

Whoever said you dont have a dizzy is correct, so you can not check timing.

Has it had this problem since you got the heads done? If so, something in the valve train could be off, or a collapsed lifter, maybe flattened cam.

You might beable to take the ignition module(under the coils) and have it tested along with the coils. One/some of them could be going bad under the heat as same principle with the injectors. Coils may check ok since you cant heat them up, so get 1 used one from a parts yard, and swap it around.

 

Just a quick note: The coolant temp sensor only talks to the computer. It doesn't do anything with the coolant temp guage. The coolant temp guage it controled by the coolant temp switch - different part.

 

Sorry guys. Gonna close this thread since it's a 4th gen, not a 3rd gen related question.