Highway speed engine surge

[jtrux]

1991 V1500

Engine idles perfectly.

Going down the highway at a constant speed I detect a very slight surge. Nothing crazy and I'd be willing to bet that a passenger might not notice it.

I'll probably drive around with my vacuum gauge hooked up just to see what's going on but figured I'd toss it up here for discussion just in case someone had an idea.

 

[jake 03]

Egr acting up maybe?

 

[Wes Harden]

probably a little lean check your fuel filter and pressure, this is TBI ?

 

[jtrux]

Yes, TBI.

Truck has new tank, pump and filter.

 

[Wes Harden]

Maybe vacuum leak. Remove air cleaner, open throttle look down throat. Sometimes the base gasket can be seen miss shaped, if it's leaking. If not check the usual ways, spay cleaner propane. Might try retorquing intake and tbi

 

[rampage]

Have you checked to see if it’s thrown any codes?

 

[1-ton]

Maybe vacuum leak. Remove air cleaner, open throttle look down throat. Sometimes the base gasket can be seen miss shaped, if it's leaking. If not check the usual ways, spay cleaner propane. Might try retorquing intake and tbi

That is what I was thinking...vacuum leak causing the engine to go lean.

 

[jtrux]

I'm gonna get my vacuum gauge hooked up tomorrow to check things out.

 

[1-ton]

I'm gonna get my vacuum gauge hooked up tomorrow to check things out.

Spraying some stater fluid or carb cleaner around the engine to see if it picks up idle is a quick way to see if you have a vacuum leak, and where the vacuum leak is located. Just be careful to not set your truck on fire.

 

[imiceman44]

Spraying some stater fluid or carb cleaner around the engine to see if it picks up idle is a quick way to see if you have a vacuum leak, and where the vacuum leak is located. Just be careful to not set your truck on fire.

I thought we just told him that a couple of days ago, turns out it was someone else, and he did find a leak