chevy truck ?

[Tyler23]

i got a 93 chevy 1500 4x4. i just put a new motor in it about 500 miles ago. and it seems when i take off it goes up to around 2300 rpms and shifts and once it shifts and the rpms drop it seems like it kinda dogs out for a sec and then kinda stumbles and catches back up. it did this with the old motor in it also. its kinda hard to explain but if anyone has any idea on if this is normal or something is happening?

Thanks

[Tyler23]

also when i put the new motor in i never did anything with the TBI or ignition system besides new plugs and a cap. the rotor and wires were replaced not to long ago.

[Jeremy airjer W]

I'm going to go out on a limp and have you try removing the vacuum line from the EGR valve and see what happens.

Otherwise there are a couple of other possibilities.

Can you feel it if you get on the gas from a dead stop?

[Macgyver55]

Thats just what I was thinking, or possibly the temperature controlled vacuum switch is stuck open. As Jer said, disconnect the EGR and plug the line then test drive it.

[Tyler23]

where is the egr at?... from a dead stop it still does it a little bit but not as bad as if im moving a little bit

[Jeremy airjer W]

It will be on the intake near the throttle body on the passenger side I think. Your looking for this.

[Tyler23]

ok thanks airjer. thats what i thought it was but wasnt sure...just unplug it and take it for a drive and see what happens then?

[Tyler23]

ok so i plug the line and caped the egr and it seemed to run worse? i didnt drive it but it idled rough. it was in my garage and it also kinda smelt like raw gas a little bit? like more than normal exhaust. and i might add it did this kinda stutter or bob in the rpms when i started it up also.. could it be something in the fuel system? i dont think anything on the tbi or anything has ever been touched Thanks guys

[Macgyver55]

Just to be clear Tyler, you need to plug the vacuum line, not the EGR. Otherwise you'll have a wide open vacuum leak. Also, the EGR valve itself could be stuck open slightly due to carbon deposit, so you may need to take it off and check that too.

[Tyler23]

oh ok that might have something to do with my problem. i caped the EGR valve to. thanks mac.

[Tyler23]

ok so i did what you guys said tonight. and it seemed to help. should i try cleaning it or just replacing it? how expensive is one?

[Big Buck Buster]

Replace the EGR..

[Tyler23]

ok guys so i havent got around to replacing the EGR as i dont drive this truck very often. but the "bob" in the rpms when i took off disappeared after i had new exhaust put on. found out the cat was really pluged so now it runs like a completely different pickup, like new... although it still kinda bob's when i start it up? is there a possibility that thats still the EGR or more of a fuel pressure problem?? i cant remember the last time the fuel filter was changed so i was gunna do that tmrw anyway....Thanks

[Tyler23]

??

[Scott K]

It could be either, along with a vacuum leak.