Hesitation on acceleration, rpm slugs and catches up..
 

Hey not sure how else to explain this, buuuut...

you're accelerating in first gear, the car hesitates. it's like someone is letting off the throttle a little, then it seems to catch and pull ahead. it's pretty minimal but definitely noticeable.

after about 4500rpm, it seems to be a smooth powerband.

below that, the tachometer needle kinda hesitates and jumps up as the car accelerates and balks. it's smoothly rising, then stops, car slows ever so slightly, then the needle jumps like a second hand on a clock then it repeats.

any ideas? things to try?

Re: Hesitation on acceleration, rpm slugs and catches up..
 

pull out the spark plug boots and check for oil leaking into the wells, if there is oil on the boots then you have a valve cover gasket leak on the o rings. Replace the o rings. Also don't forget to clean the spark boots on the inside where the oil probably got into, then after you clean off the boots take out the spark plugs too and give those a good cleaning too. GL!

Re: Hesitation on acceleration, rpm slugs and catches up..
 

btw if that doesn't work then I would try replacing the fuel filter

Re: Hesitation on acceleration, rpm slugs and catches up..
 

I will replace the fuel filter tomorrow asap.

There is no evidence of oil in the spark plug wells. They are clean, dry, and appear to be perfect condition.

Thanks.

bummmp

Re: Hesitation on acceleration, rpm slugs and catches up..
 

bummmmp sure this has happened to others.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

bump bump sorry it didn't help :/ i guess try checking fuel pressure and if not that then maybe taking a look at the timing might help too.. GL!

Re: Hesitation on acceleration, rpm slugs and catches up..
 

Could be bad plug(s), plug wire(s), dirty injector(s) or something in your distributor. Any CELs?

Re: Hesitation on acceleration, rpm slugs and catches up..
 

No check engine lights. Cap and rotor both look fine.

Plugs and wires are new.

bumppppp

Re: Hesitation on acceleration, rpm slugs and catches up..
 

Check your vacuum hoses, a vacuum leak can cause problems like this.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

True, I've had a similiar problem. Look for vacuum leaks. If not possibly something with the fuel system.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

yup i had this problem also...did u just recently remove something recently like say idk...your timing belt? and now its like that? does it feel like its choking? or does it accelerate slow even tho your gunning it at first then it kicks in? if its choking its a vacuum leak...if it accelerates slow then your timing may be off...

Re: Hesitation on acceleration, rpm slugs and catches up..
 

vacuum leak good idea. heres a link to show how to check for them
http://www.youtube.com/watch?v=9CPqbaSgcok

Re: Hesitation on acceleration, rpm slugs and catches up..
 

sounds to me like a bad injector, take a flat head screwdriver and press the handle into your ear and the other end on the injector you should hear a ticking sound and check all of them to make sure its a consistant sound. I had a z6 that was doing the same thing and replaced the injectors and good as new. If it were a vacuum leak it would idle high and just run like complete shit.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

soo op did you ever figure out what the problem was?

Re: Hesitation on acceleration, rpm slugs and catches up..
 

sounds like ignition system problem. If you don't have a vacuum leak, I would think it's your ICM. Does it just hesitate when you put a lot of load on the engine? or can you ease on up in 1st gear with no seemingly hesitant acceleration?

Re: Hesitation on acceleration, rpm slugs and catches up..
 

I loled at this....

Re: Hesitation on acceleration, rpm slugs and catches up..
 

I've been busy. I just got 5 gallons of high-octane premium gas. I am about to put it into my tank, idle the car up to operating temperature, then go for a drive. I am hoping condensation in the gas tank was the problem.

I will post back after I take a lap around the block.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

just put in 5 gallons of high octane fresh gas. condensation in the gas doesn't appear to be the problem. took it for a short drive around the block, still seems to hesitate.

what is icm... there are thousands of acronyms.

it hesitates accelerating slowly or fast. the speed i throttle it up makes no impact on the hesitation. it's the same.

i will do this asap.

i believe the timing is accurate. i have only checked it 4 times. it hesitates, it doesn't bog then catch and accelerate. its smooth, then sorta balks like i let off the throttle, then accelerates again and repeats.

i will also look into vacuum leaks.

anyone else? thanks HT

oh btw. don't but ebay hood pins. they just stripped out on that "short drive" i just took and hood now needs replacement, as with windshield. fyi.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

damn sorry to hear about your hood/windshield. Well if none of the above suggestions worked out for you I guess you'd have to go look at other components that deal with fuel/ignition. Maybe fuel pump? Also is the gas cap seal still good, surprisingly little things like this could make a difference too.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

bummmmp

Re: Hesitation on acceleration, rpm slugs and catches up..
 

How about ignition timing? Want to give it a shot, just for a giggle, loosen the 3 bolts holding the distributor on and shift it a bit towards the firewall, this will advance timing, but you might experience some pinging.
Or if you have access to a timing light just set it, and forget it- :D

Re: Hesitation on acceleration, rpm slugs and catches up..
 

You shouldn't just loosen the distributor and mess with timing on your own. That's just foolish. Get it properly adjusted and/or tuned.

When was the last time the rotor/cap were actually replaced? Don't go by something "looking" fine. Depending on driving conditions, you may have to change them more often.

Other areas you could look into are your o2 sensors, PCV valve, and fuel injectors.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

It's not as foolish as adjusting cam gears on your own, which, if adjusted incorrectly can cause serious engine damage. Adjusting a distributor is no big thing, and, it's not so foolish.. if said person does not have the means to get it 'properly tuned/adjusted'

So go ahead, mark the area where the top bolt goes through with a line to ensure that you can return the distributor to it's original location, and adjust it.. drive it normally and see if the hesitation disspiates. If not, then it could be as somewhat stated before, a lazy o2.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

thanks for all the shouts guys.

eviction leaves this car on the back burner. got her running, moved her, now my baby sits until i can throw money at it (parts, timing light, cam gears, new cap, etc - ya'll know how it is with these cars...)

i love all the feedback, keep it comin and the second i have a spare buck to throw at her, my baby will get every single thing in this thread triple checked and verified.

at that point i'll have videos, high-quality audio clips, pixorz, and enough words for a book on my observations and test results.

bummmmp. this is a work log, i'll do all this when i can find the coin/time.

uuuurrrvery day i'm hustlin.

Re: Hesitation on acceleration, rpm slugs and catches up..
 

oh yea. annnnd.

ebay f4gg0try leaves me a broken (completely) windshield and a destroyed hood.

hoodpins failed on test drive, hood smashed windshield. that's another 500 minimum before she's on the road. the sh!te adds up at the bottom.

lesson - no egay. ever. ever ever. never ever neverever ever.