Bad stumble on acceleration coming home last week- fixed!!

[Dirtball]

On my way home from getting all the parts outlined elsewhere my truck started running worse and worse, especially going uphill. It would idle, but when it got under load it would start stumbling and, I thought, missing. I took a longer route home with fewer hills to give myself some peace of mind. When I got home and pulled into the drive it was idling fine. When I would gas it it would stumble. I popped the hood and you could hear a distinct whistling sound that was not there before.

Is there anyone who DOESN'T think it's a vacuum leak?

I couldn't find it... but as tired and tense as I was I just wanted to get everything unloaded and get into the house to eat pizza and watch the Braves.

I'll tackle it Monday...

[sappy76]

Any mods to the ignition? I fought the "stumbles" for years. It wasn't until I went to a larger cap on the rotor (juice box) upgrade that I finally got rid of it. Check the inside of your cab for carbon tracks leading to the various pickup points for the spark plugs. Was it raining or the engine wet causing a spark short somewhere? Also check your vacuum, you might have a leak in a hose.

[Dirtball]

Yeah, I kind of figured/hoped that the whistling sound I heard was a vac leak. I'll get it into the garage tomorrow and get it checked out...

[JeepsAndGuns]

How did you check for vaccume leaks? A old trick I have heard, is to take a can of starting fluid or carb cleaner and start spraying the carb, gaskets, and anywhere else that vaccume may leak. If its leaking, it will suck the carb cleaner in and you will hear the idle change.

[littlebuck23]

Whisle as u know is a dead giveaway to a vac leak. However. You engine might be suffering from fuel starvation. Just for fun replace the filter. I like to blow in the newone and in the removed one to see how clogged up they are.

[Dirtball]

How did you check for vaccume leaks? A old trick I have heard, is to take a can of starting fluid or carb cleaner and start spraying the carb, gaskets, and anywhere else that vaccume may leak. If its leaking, it will suck the carb cleaner in and you will hear the idle change.

I got some starting fluid today... but by the time we got home from Wally World and ate my Monday Night Comedies were on... it's my one big TV night.

[scantar]

I would be very careful about spraying starter fluid around the engine (as in I wouldn't do it!). It's highly combustible whereas carb cleaner is not. If you really really want to use starter fluid, have a fire extinguisher strapped to your helmet.

Steve

[JeepsAndGuns]

Yea, carb cleaner is better, but starting fluid will work. Just do it with the engine cool, and only doo it in short bursts. Dont hose it down too much. Keep it away from the exhaust!! But you knew that already.

[Dirtball]

I did the starter fluid thing and, since there are no vacuum hoses running anywhere near my exhaust manifolds, everything went fine. Also, no vacuum leaks.

However... today, I replaced the fuel filter. Simplest fix first as I usually suggest on here. And guess what? That was the fix. Isn't it amazing? I didn't really think it was electrical since it wasn't backfiring or spitting/sputtering. I have no clue what the whistling sound was. It's not doing it now (and it wasn't doing it this morning when I drove it and it still had the stumble).

Anyway, once again, I get lucky and have a quick fix.

Now if that new Qtrac and Lockright would both just jump in there as easily.

[JeepsAndGuns]

I like those clear plastic fuel filters. That way you can see whats in there, and when it needs changed.

[silvercert]

I did the starter fluid thing and, since there are no vacuum hoses running anywhere near my exhaust manifolds, everything went fine. Also, no vacuum leaks.

However... today, I replaced the fuel filter. Simplest fix first as I usually suggest on here. And guess what? That was the fix. Isn't it amazing? I didn't really think it was electrical since it wasn't backfiring or spitting/sputtering. I have no clue what the whistling sound was. It's not doing it now (and it wasn't doing it this morning when I drove it and it still had the stumble).

Anyway, once again, I get lucky and have a quick fix.

Now if that new Qtrac and Lockright would both just jump in there as easily.

I had a whistle and it turned out to be my carb gaskets.

[Chris P.]

Yep, carb gaskets can whistle.

Once I had a whistle I couldn't track down. It didn't happen all of the time. One day I took the carb off for something unrelated and found the plastic spacer was cracked. I swapped it out and never had anymore whistle.

[newtojeeps]

I like those clear plastic fuel filters. That way you can see whats in there, and when it needs changed.

They pulled those off the shelf here in CA. They are all the white plastic now.
I think the Alcohol in the fuel may have been an issue but not sure.