car hesitates and hicups over 5K
 

Hey guys,

My cars got a weird hesitation problem. It feels like a car with the 3800 hesitation, but it does it ever 500RPMs or so after about 5000. I thought it was grounds so i went to the parts store and got some 4ga grounds, no avail. I changed out the MAP sensor and the hose, no avail there either. IM pretty much stuck, the TPS is great, no cats to be clogged, everything set like it should. Anyone? Thanks again fella's

i had a simmular problem, i switch gas from 87 to 89 and problem went away. y it was doing it, i could never figure out though



-Shawn

what the hell really? How is your timing? Hmm.. ill try that 89 gas shit.. if it works ill send my car to Jessie, LMFAO! I have a serious fucking street port, but i still dont see why it would be doing that. The only thing i could think of is an injector being gay, or a coil back skiping out at higher revs.. both dont make much sense though. Thanks man, ill try what you say and get back to the forum.

well i just figured my injectors were cloged and we were all out of the cheapo gas where i work at so i filled it up on 89. and its been day #2 (240 miles on this tank so far) and in hasn't done it yet so i guess the injectors need a cleaning


-Shawn

tps?

well you're runnin 15 degrees of advance timing and a mild street port which causes way more lap n duration and only running 87 octane? any engine would backfire on highend doing that switch to 92-94

Is the "pill" still in the vac line to the boost (AKA pressure) sensor? Was the cause of my high RPM studder.

Start with a new fuel filter, if it hasn't been replaced recently....

Nope, does it when its set to stock initial timing. Also, i have ran, and other people have ran over 15 advance on 87 just fine, its not that, i promise you that.

Also, brand new fuel filter as well.

The pill in the MAP, i think thats the problem, but another problem, i cant get ahold of another one. But, check this out, my freind (Detruich) on the forum had a regular vac line on there, no pill, and runs fine. Same with Rotorific, damn Rx7s.... i wish chevy woulda got the dorito motor, not this stupid import company. ;)

It has something to do with your fuel line. Chick filter, pump, or injectors.

All new line, all new pump, new filter.. Next?

Nope go fish sir

you can run 87 up to 20 degrees advanced timing and an engine will NOT backfire when advanced because it is burning the fuel more efficently. -Gabe

I just recently learned about the pill in the vacc line. Since I've re-installed it (the pill) my car runs better again. I'd suggest you find and replace the orifice. I got mine from Brian at Mazdaformance. Took the opportunity to order some oil filters and sparkplugs while I was at it. Might as well make the shipping cost worthwile.

Thanks man, im going to look for one at the salvage yard, if nothing comes up ill deffinatly look into your reconmendation. Thanks again everyone.

bump

There is no majic to the "pill" it is just an orifice. The dia of the hole is called out in the parts list. I just used a piece of plastic with a 1/16 hole drilled in it. That hole is a little large but it was the smallest bit I had. Car runs perfect again.