Car is in my signature, I recently encountered something odd while on a short road trip and wanted to see if you guys had any ideas.

The road trip is about a 1 hour drive, driving there I had no issues, just breezed along at 75 the whole way.
But coming back I got this weird behavior as soon as I hit around 60-65 mph, if I gave it a little extra gas (say to pass another car) it would go all mushy and lose power dramatically, once I took my foot off the accelerator a bit it would resume normal operation. It felt like it wasn't getting the fuel (if you've ever run out of gas on the highway, and the car stalls, that's what it felt like, except it didn't stall). Also I noticed that this would only happen at highway speeds, so when I pulled over to check the engine and gas up I was able to tromp on the accelerator and it took off like normal, all the way up to highway speed then got mushy again. Normally the car is extremely responsive with good acceleration at ANY speed so this is very strange.

Any advice or diagnoses or things to look for would be very much appreciated, thanks!

 

then you play with the linkage on the carb, does it squirt fuel in?

If not, or if its less than it should be, consider a new fuel pump and new fuel filter... sounds like it wasnt getting the fuel it craved when you went to push oit, somethings not delivering gas.

 

Definately a fuel problem. It may have trash in it and the jets are getting stopped up. If youhave a fuel pressure guage on your fuel line I'd look there first. You should have around 6 PSI. If you don't have one I would check the filter. However, this more than likely isnt the problem. I am leaning towards a problem within the carb. This is because if the float bowls are full then it should pull just fine until they empty. The pump doest push fuel into the engine like a fuel injection car; the engine sucks fuelfrom the float bowls through the jets and out theventuries. The pump only serves to keep the float bowls full, so it would pull fine for a few seconds before the bowls emptied, then it would fall on its face. I'm willing to bet its dirty jets and/or accelerator pump.

 

probably a bad fuel pump...Replace it.

Mine would do something similar. Its fine in neutral because the engine isnt loaded but when you load the engine it out runs the fuel volume and several cylinders loose fire and power drops off until you back off and fuel can refill the floats.

I was having problems between 1st and 2nd accelerating. 1st was fine then it would fall on its face going into 2nd.

I got a fuel pressure gauge and I watched it as I accelerated. 1st: 6lbs...5.....4... 2nd gear..3...2..1.0.stumble

Replaced fuel pump works great.

Might want to check filters first however.

-Gun

 

Classic symptom of a clogging fuel filter or internally leaking fuel pump diaphram.

 

yeah i just went through all this. I was getting fuel through the jets, but very little. took the hose off the carb and put t in a bottle, cranked it, nothing.

clear fuel filter wasnt filling... i replaced a pump... TWICE. still nothing.

finally took the line off BEFORE the filter between pump and carb, cranked it and it filled the bottle in a matter of seconds. Replaced the filter, returned the two pumps I didnt need, and was good to go.

Itd be a shame to assume its a carb without testing....


Take the hose off at the carb, put it in a plastic coke bottle or something and crank the engine. n a matter of seconds it should fill the bottle. If nothing, put that hose back on and test again BEFORE the filter.

If it fills, you know its your filter.

if the pop bottle doesnt fill, its your pump.