Hi, I went on and off with my car and still the hesitation problem presisted.

I took it to a mechanic and they checked the fuel preassure and it was within specs.
The vacum was what they were suspecting.
First in Idle was 17hg, in drive it was about 1 or 2hg. When powerbraking the vacum was 0.
I am wondering if this looks like a vacum leak???

Also I can hear a loud hiss (much louder than what TBI makes) coming from the TBI. Like its sucking harder???

Also, my ingnition components tested all OK too.

My car now boggs down pretty dang good when its warming up. I give it gas, but the car is not going anywhere. Than I go down on the pedal and the car barely moves. If I let go and give it gas again the car runs fine?? WTF is wrong with this pile of cow dung.???

 

A vacuum leak around the TBI would basically be like opening the throttle. The engine would have a fast idle, but basically run normally.

Does the timing advance properly? Are you getting any knock counts? Lots of counts will slow the car down to a crawl because theres no spark advance. How does the car idle? Do you still have a cat? Have you had it checked to make sure it didnt have a meltdown? A degraded cat or exhaust restriction will hiss real loud due to the exhaust gasses squeezing through it at nearly the speed of sound.

To test for an exhaust restriction, hook up a vacuum gauge. Snap the throttle open and rev the engine up to around 4k and allow the throttle to snap shut. If the vac doesnt immediatly shoot up to around 20-25 inHg, then there is probably a restriction.

 

After re-reading the post, a clogged cat sounds unlikely if it goes fine after you let off. Can you datalog? That would really help show what the problem may be.

 

I will get to datalogging next month (when I get some funds).
However, today I noticed something, that I think it was doing it before, but never paid attention to it.

When I give it gas off idle and immidiately go, the car would hesitate, and as soon as I let off the gas I can hear the car come up again. It feels like the car responds to the gas in sec. or two!
Like there is delay!

 

Few other things I've noticed about the car today.

First, the idle would drop under 600 and the needle would shake, between 520-580 (around there). I would hold the brake and give it gas. Sometimes, the car would shake a bit and the RPM would drop and quickly come back up. Most of the time I'd give it gas and raise it to 700 and than the car's idle would stabilize at 600.
Also, when I slow down to 20mph it feels like the car is not downshifting to second, it downshifts at around 16mph (note i have 3.23 gears.
I have few questions.

1/ What does make a car want more timing???
2. Would incorrect tranny fluid level make the car not downshift at the right point.
3. I think one of my calipers has seized in the righ rear. However, I still use the drum proportioning valve. So, I don't think its that important, but would a seized caliper make me go to 1000rpms and stop there when am powerbraking???

 

Also, the car seems to be having many hesitation problems in open loop when its warming up.
Once it warms up its fine, with the 20mph feeling like its in third, and can't do a burnout!

I heard from a member on this board, that the car could be getting too much fuel, thus making me adjust the air screw almost all the way out. I am runing the TBIchips.com chip, and I did try running it with the stock chip, same thing.

Anyone have any idea???

I will get to datalogging, as soon as I get the money for the cable.
(I get paid once a month, so its a pain in the ***).

 

Air screw?

 

idle screw! The screw u adjust for iac, and minimum air.