gfunk68

my 1993 brilliant black rx7 is hesitating at 4k rpm and its driving me crazy!

i got it from some dude on ebay and he said that becasue of the exhaust straight pipes is the reason it hesitates and to try and put an FC on it and it'll work properly

any h town folks have an extra powerFC with a similar setup on which i can test this on? (i need to know if he's BSing me before its too late for me to sue him for ebay fraud)

also, im trying to buy some nice simple mods for my rx, is the Greddy Type-S BOV

Sideways7

iTrader: (7)

I think there a other ways to fix it besides going to a power fc. Search in the 3rd gen section for "3800 rpm hesitation" and you should come up with something.

gfunk68

wow thanks!

gfunk68

it seems most people have the 3800 rpm hesitation on TIIs......i have an FD


i'll do a little backround info see if this helps

the car when i first got it it was running fine, then the guy let it get too low on gas before selling it to me and clogged the fuel pump........the guy thought it was a ground and he fixed that (i think) then he replaced the fuel pump when that didnt work, then the a/c went out.......he replaced that (which still turns off when i idle for a long time for some strange reason and i have to turn it on and off over and over for it to come alive agian), then it started hesitating, then the odometer kept turning off and my check engine light came on everytime it'd hesitate

now it just hesitates and its somewhat annoying.....in first gear its like less than a second of hesitation at 4k rpm, 2nd gear 3 secs at 3500rpm....etc till 5th gear when i can barely get over 80mph

after the hesitations, it always takes off and puts me back to my seat in that oh so good rotary power

from what i seen it seems the Turbo II have problems with o2 sensors and grounds and stuff.

btw, im definatly coming out in oct. for the meet!!!

cewrx7r1

iTrader: (2)

Could be one of the transmission switches or TPS being bad for the hesitation, but those would not cause the other problems.

Thus I would think it is a wiring problem with a bad connection affect current flow.

Sideways7

iTrader: (7)

Well, I am familiar with 2nd gens, not thirds. 2nd gens (all, not just turbos) have the 3800 rpm hesitation due to the secondaries not kicking in right on time for some reason or another, I just assumed that 3rd gens would experience that sometimes as well. It still isn't something that requires a power fc to fix, though. I would ask about it in the 3rd gen section and try to get it fixed the right way, not with a band-aid.

rotarygod

iTrader: (1)

FD's are notoriously bad for having issues with the twin turbo system not operating properly. With almost 80 vacuum lines for that stupid system to work properly, it's no wonder. If so much as one thing goes wrong, the whole system behaves very differently. Most people that have issues have it here and almost everyone with that car will have one at some point in time. Unfortunately this can be a frustrating and time consuming thing to go over but I'd start looking there first. Get a hold of a manual and go over everything one by one. I highly doubt a Power FC will solve your issues. That really sounds like an excuse. There are many people that have run a different exhaust with the stock ecu and your problem doesn't sound related.

The 3800 rpm hesitation is a 2nd gen problem. It's not only limited to the Turbos though as the n/a's also had the issue. It could be anything from a bad engine ground to a sticking secondary throttle plate.

cewrx7r1

iTrader: (2)

The FD hesitation problem occcurs at 3000rpm but only while cruising or slowly accelerating. If you give it full throtle below 3000 it will not occur. This is one problem that the PFC fixes as soon as it it installed.

But then the PFC can be more finicky when it comes to idle control and many times requires the owner to make minor air flow adjustments to the throttle body.
But this is not a problem for the experienced.

gfunk68

cruising or slowly accelerating? what does that mean :P i drive an rx7 not a ****** corolla

twokrx7

iTrader: (1)

Your A/C sounds like it's low on freon. If it's low it can get cold enough to freeze the evap core and this will shut the system off until core temps come back up.

Your 3800 rpm hesitation could be many things as mentioned above. The PFC gives a tremendous advantage for troubleshooting as it provides lots of data and with a datalogit you can datalog most engine parameters for even better troubleshooting. Good luck finding a PFC laying around, most are installed and making owners very happy (except for the occasional idle bs).

I'll be at the meet so perhaps we can talk about your issue.