Shaking

[dylan94sierra]

1994 1500 z71 350tbi

Truck has recently started a shake at lower rpms, but it is not really like a misfire. It does it in park, gear, and neutral. After about 2500 rpms it goes away. About 2 months ago I did plugs wires cap and rotor. And help is greatly appreciated

 

[skylark]

Check to make sure that the plug wires haven't come loose from the distributor cap or spark plugs.

 

[rosco]

Check to make sure that the plug wires haven't come loose from the distributor cap or spark plugs.

What he said. I was in a company truck a few years back, 1995 ( I think ) S-10 with the 4.3. Would run like crap until one day it started running so bad I had to pull over an hour from the shop. Turns out a plug had worked loose and ended up falling out. I lucked out and had my socket set with me. Ran pretty good after that, but it was the ammo we needed to finally get the boss to take it in for a tune up. Ran perfect after the tune up.

 

[dylan94sierra]

I checked the wires

 

[lester622]

Check the firing order on the cap, I had the same thing happened to a ford truck I put a motor in and had cylinder 5 and 6 backwards on the cap.

 

[dylan94sierra]

It's been running great for months after my tune up until today through. Could it be a vacuum leak? It's gone at high rpms. I'm also idling around 500-600

 

[lester622]

It could be a vacuum leak. Take starting fluid and spray it around the intake and other areas under the hood. If the motor revs up you found it.

 

[Jewbacca]

Agreed might be intake. Common problem om our trucks.