hesitation at acceleration
 

Hey all,

I have 350 tpi engine and intermittently it will hesitate when I step on the
gas. If I ease into it, most of the time the response is smooth. When I go to
punch it (even slightly), the car hesitates and acts like it wants to cut off.
I had recently replaced the plugs, fuel pump, and filter. Didn't change the
wires yet (the previous owner has 7mm wires on there and I don't think that
is the right size, is it??????/).
When I get a chance, I will go in search of any vacuum leaks but I am pretty
sure that I may need to replace a sensor or two (or more). I just don't know
which I should start with (IAC, MAP or what)???
What do you guys suggest?
And by the way, the car isn't throwing any codes but the initial "handshake".

Re: hesitation at acceleration
 

Hey, I'm having the same problem.

If I ease the pedal down, it accelerates okay, but if I floor it, it idles and acts like it doesn't want to do anything. Still trying to figure it out.

I've swapped the ECM, fuel filter, fuel pressure regulator, injectors, the mass air flow sensor (which wasn't cheap).

I have replaced the IAC, and no difference there, I also swapped out the Throttle position sensor, with no change, and there does not appear to be a MAP sensor on my car, nor was there ever.

I think tracking the vacuum lines for a leak would be a good start, I think that's where I'm off to next.

This condition is very irritating, as I use my car as a driver, and love to squeal the tires at every turn. Problem is, I can't cause of this :bs:

If I find something out I'll PM you or something.

Re: hesitation at acceleration
 

Cool thanks.
I forgot to mention to our resident tekkies that sometimes the car idles
rough but most of time it idles relatively smooth.

Re: hesitation at acceleration
 

hey
im having the same problem with my 305 4 barrel. check out my post and join, the experts have given me some ideas.

Re: hesitation at acceleration
 

I've had the idea thrown at me that there might be a problem with the spark advance that is causing this condition. I think I'll look into it.

Re: hesitation at acceleration
 

I'd ohm out the injectors and do a fuel pressure leakdown test. The old multecs dont like the ethanol in the fuel and are starting to give up the ghost in a lot of cars.

Re: hesitation at acceleration
 

I pulled the intake off a while ago and did a pressure test on all 8 injectors, and all were good. It wasn't my problem, but some of you other guys might want to look into it.