Car hesitates after 3,000rpm..need help

spoolin_gt

New member
It started happening when my it started to get cold...Everytime I drive the car..it would start hesitating after 3,000rpm-4,000...i checked all the connections for the front mount to see if there was any leak but didn't see nothing....I dont know if it's because of the weather...or when I installed my boost controller...I also disconnected the vsv...the temp sensor on the cluster is past half...i changed the thermostat and it's still the same....one thing I noticed is that when I disconnect the battery and reset the ecu..it runs fine for a while..but goes back to how it is after...I dont know if my overboosting before affected this...because the mbc was clogged before and it reached 20psi at 5krpm...the hesitation feels like a fuel cut...feels like the car is running out of breath and gas....im going to change the fuel filter to see if it's clogged up since it hasn't been changed....dont know what else is causing this but would like to know....i hate driving without the car pulling me to the seat....anyone else experiencing this problem????thanks in advance..

Gian
 

gpmarzan

New member
spoolin_gt":22nj2lqb said:
It started happening when my it started to get cold...Everytime I drive the car..it would start hesitating after 3,000rpm-4,000...i checked all the connections for the front mount to see if there was any leak but didn't see nothing....I dont know if it's because of the weather...or when I installed my boost controller...I also disconnected the vsv...the temp sensor on the cluster is past half...i changed the thermostat and it's still the same....one thing I noticed is that when I disconnect the battery and reset the ecu..it runs fine for a while..but goes back to how it is after...I dont know if my overboosting before affected this...because the mbc was clogged before and it reached 20psi at 5krpm...the hesitation feels like a fuel cut...feels like the car is running out of breath and gas....im going to change the fuel filter to see if it's clogged up since it hasn't been changed....dont know what else is causing this but would like to know....i hate driving without the car pulling me to the seat....anyone else experiencing this problem????thanks in advance..

Gian

first off..nice name (same as mine :D )
i had the same problem with my st165. mine hesitated when i try to go past 4psi. it was my dist cap/rotor. the cap was all corroded inside and the rotor had a black tip. also, check your spark plugs gap. i remember not checking mine when i changed my plugs and it started hesitating. wires, dist cap/rotor, and plug gaps should be the first to check.
 

alltracman78

Active member
If it clears up after you reset the ecu, it's probably not the cap/rotor/plugs/wires. Might be timing. I was having a real problem with my 92, it wasn't pulling smoothly or hard at higher rpms. I went through all kinds of crap, finally ended up swapping in my 93 ecu, problem gone.
I think my ecu [and poss igniter] was having issues.
Also could be misfiring [related to problem above].
 

spoolin_gt

New member
we did the timing..and it wasn't it..i'll try to play around with the timing and see how it goes...but i guess it's got something more to do with fuel and air than anything else....

alltracman78..so you changed your ecu and now your problem is solved???i'll try swapping mine with another ecu....but i doubt that it is it....im changing my fuel filter tomorrow to see if it's clogged up and stuff...check the fuel pressure..see if it's giving out the right amount of fuel...play with the maf....

i also forgot to mention..that my idle is really high...i set it at the very lowest and it still idles at 1400...sometimse drop to 1000rpm..... :shrug:
 

alltracman78

Active member
I don't mean idle timing. As the engine raises rpms it constantly adjusts timing. Even if your base timing is correct, the ecu can still retard timing a whole lot in the higher rpms. This can potentially rob you of alot of power.
I only suggested the ecu 'cause you said when you reset it it goes away for a lil while. How bad is the hesitation? Fuel cut is really violent. Feels almost like your hitting a wall. If it's that bad, probably isn't timing.
Timing could cause the combustion temps to be high, that might be why your temp gauge is reading hot [it reads the coolant temp right after the head].
How did you adjust idle speed? If you have a 2nd gen engine the idle speed is adjusted by the ecu, you can't adjust it [unless you're running a piggy back].
 

spoolin_gt

New member
so finally....after 5 hours of trying to figure out what is causing the hesitation...i finally found out what it was....we checked and replaced the fuel filter...and it wasn't it...played with the maf...nothing....took 3 hours for us to figure out why the cel wasn't working and no luck...and finally...we started looking for loose sensors....and what we found out was that the TPS was loose...one screw was missing...so we took it out..cleaned it....put it back on....tightened it....and done!!!! :D ...my car is back to normal again......thanks everyone for your input..... :smokes:
 

alltracman78

Active member
Just a FYI, on the 3S tps, it's the same as the 5SFE atomatic with ect. At least the 90/91, tho I don't think the 92/93 are any different.
 

spoolin_gt

New member
alright..for some reason...my problem is back again...it starts hesitating after 5k this time....i don't know what's causing it...but maybe the tps got damaged before since it only had one screw and something could have defected it.....i have a spare tps lying around so i'll swap that tonight...my other problem now is that my car idles quite high...i set the idle at the very lowest....and it is still at 1400rpm....anyone else experiencing this???thanks in advance..
 
Top