95 S14 hesitates accelerating

[bleufiend]

Ive got a 95 S14 with hesitation when your trying to accelerate, starts at roughly 3800RPM and then it smoothes out and runs better from 4200 but just doesnt seem like its got the speed that it should. Its got a new cap and rotor, just put a new headgasket on it about a month ago, new valve stem seals. Checked the resistance on the plug wires and there all below 10k ohms. Replaced the plugs today with the correct ones, the last owner put in one step colder ngk's so i bought the correct temp range plugs and that fixed my laggy off idle response and acceleration thru out the rev range but Ive still got a flat spot around 4000rpm. Also intermittently when accelerating off of idle it will just bog and have no acceleration at all which is nerve wracking esp when you are trying to pull out into traffic and get going.

Checked fault codes and the only ones I have are evap canister purge, knock sensor and crank sensor. Thought the crank sensor may have something to do with it but according to the service manual it only acts as a misfiring detection device and does not contribute to the control of ignition.

Any help is appreciated.

[Fibre guy]

Wifes s14 is the same way. Feels like high 3000 is getting close to red line right?2000-ish rpm later the power kicks back in enough to chirp the rears in 2nd on a dry day.I made a thread about it a while ago and got no response. I guess its a rare KA thing. Here it is: zerothread?id=420625

[bleufiend]

The description of your problem is probably the closest match Ive seen to mine on the web. Only difference is that mines is only that very small spread right there at 3800 to 4200 at least thats where the tach needle drags at and it just feels like your struggling to get thru it, it still accelerates but just very slowly, intake gets loud and all of that, once it passess that point it seems to pick back up but doesnt really have the juice............at least to me I guess like it should pulling all the way to redline.

It seems to me like the distributor is not advancing or something. Also last night I tryed taking the vacuum line off of the fuel pressure reg to see if that made any difference and it had no results either.

[zachattack_5491]

I had the same problem for about 4 months in my S13. Your symptoms sound exactly like mine. I'm gonna just go through the things that I did. Make sure you double check everything, because it will end up being the smallest thing.

I checked/adjusted/replaced the throttle position sensor, added new ground wires and replaced old ones, made sure the cat wasn't clogged, new cap/rotor/wires/plugs, seafoamed, cleaned IACV, and a whole ton of extra things.

In most cases it's the ground wires or the tps that's causing the hesitation problems. Mine ended up being a broken plug wire.

Good luck, it's a rough road trying to fix hesitation.

[Fibre guy]

Seems like its not so rare....

[nuts510]

definitely check your TPS switch, but since you were getting a code on the crank angle sensor, I would seriously consider trying another distributor I have also seen the ignition coil that is located in side the distributor cap makes for some very unusual and drivability problems. You might also want to try putting a timing light on your engine and watch and see if the timing is doing some fun jumping around. Try advancing your ignition timing some and see if that calls is a difference in the way the car drives. Also examined the district are Very very closely and make sure there is no oil accumulating inside the distributor.

[zachattack_5491]

definitely check your TPS switch, but since you were getting a code on the crank angle sensor, I would seriously consider trying another distributor I have also seen the ignition coil that is located in side the distributor cap makes for some very unusual and drivability problems. You might also want to try putting a timing light on your engine and watch and see if the timing is doing some fun jumping around. Try advancing your ignition timing some and see if that calls is a difference in the way the car drives. Also examined the district are Very very closely and make sure there is no oil accumulating inside the distributor.

I knew I was forgetting something. Check and adjust you're timing for sure. I forgot that you were getting a crank angle sensor code.