Throttle Sputter at high way speeds

[jaredg]

Hey all,
I am experiencing what feels like throttle cut off at around 49 miles per hour. I have noticed that as I held my foot down on the accelerator, the engine would stop accelerating at times. It was as if the gas was restricted for short intervals. I would let off the pedal for a few seconds, then press down and it would be ok. This issue used to happen sporadically, certainly not all the time as I know for a fact that I have gotten her pushing 65 mph quite often in the past. However, yesterday I drove her quite a bit on the highway and could not at any point in time get her over 49 mph. I know that the fuel filter was just changed but wondering if possibly a symptom of a bad fuel pump? I actually have a brand new one that I haven't had time to install. What are your thoughts?

To refresh your memory, its a 1987 366 gas engine with a rebuilt Holley 4152 carb.

thanks for your help//

[bapos]

I could be a fuel pump but not likely? I have had them go out all the sudden and have them take forever.

Few questions.....

1) when was the last time the fuel filters were changed? <<<<<<<<<<<<<<<< sorry reread your posting so disregaurd.

2) Are there any after market fuel filters on it? Paper filter ones are sort of bad if they sit for a long time.

3) Last time the carb was redone?

I recently had a 2 barrel rochester in my 3/4 ton with a 350 act like jeckel and hyde. Replaced all the filters in it. Drove it 70 mph down the hiway and thought I had it whipped. Drove to get it inspected. Only went a 1/4 mile down the road before it was choking like it had a chicken bone. I pulled the 2 barrel off my demoltion derby race car and put it on... ran like a champ.

My feelings on carbs there days is you better have a spare..... ON EVERYTHING. The additives they have in gas will gum up one faster than you can imagine. This year alone I have replaced carbs on my generator...log splitter....weedeater....and the 3/4 ton. And yes they all have a spare now.

Sounds like carb to me but you have to guess it down and see what you can make happen.

[jaredg]

First, thanks for replying. To be honest, I think the carb needs to be professionally adjusted or tweeked. Its a rebuilt carb that I put on a year ago but many people have told me adjusting these things to get the engine to run proper is rather intricate. Another odd thing that the engine does is when I start her up for the first time of the day, I have to keep my foot on the pedal to keep it running or else it will stall out. Once I run the bus for a few miles, its ok.

[bapos]

I can tell you I had this same very thing you are describing in your last reply on my 3/4 ton. It does not take much with the fuel of today for a carb to get jacked up.

It could need an adjustment. By the sounds of it something is still open or not sealing when you first start it up. Obviously when it heats up it seals.

Like I said theres nothing wrong with having a spare if you can budget it.


Bapos