Hey all...

As the title suggests, I have a high RPM miss under load. Let me back up though....


Beginning in the early spring, I had some key issues. Occasionally, the security light would come on and I'd have to wait 5 minutes before being able to start the car again. I never really thought much of it.

I have also noticed that for about the past 2 years, I have had a misfire and dimming lights (very very brief dimming, like 1/10th of a second, headlights and dashboard) only with the defrost on .

I never really had thought much more of it until lately, I'm getting a bad hesitation in the higher RPM's (above 4000) under load, generally on the highway. It seems ok under those RPM's, other than being a little harder to start. It feels like it did before, when my defrost was running, even when it's not.

I do have new plugs, I've just been dreading putting them in, it'll be my first time The car is pretty much stock. I just wondered if there was something obvious, I've been reading threads from the search function for about 2 hours and didn't really see anything about the defroster causing a miss.

 

Ooops, how could I forget.

Just before this problem started, my TCS and ABS lights came on (maybe a month ago) while idling at a drive-through. I came home and poured over my haynes manual and I went out and re-started it, and everything was fine. Occasionally now though, those lights will come on, my ABS stops working (I thought I lost my brakes totally on the way home from work today, but the brakes are usually fine).

also had a new clutch kit, UV joint and a few other unrelated items put in about 2 months ago. Don't think it's related, It ran great after it came out of the shop.

 

HUmm sounds kinda like a lil problem i havnt taken the time to look for yet. Lemme start by saying i just got the car a couple months ago and just started fixxing stuff and making sure everything is as it should be. The car was sold to me with the old owner telling me the abs inop light would come on in the rain. Well it didnt come on till 2-3 weeks after i bought the car, and when it started it was intermitant but the light came on more then it was off. After having some front tires mounted, the abs inop light would come on and stay on with the key on and the engine still off. I complained about the problem to the tire shop (i was mad at em caus ethey had to remount my tires 3 times cause theyre employee apperently has never seen directional and driver/pass sided tires before..ala the goodyear GSC's) Well they told me the passenger side front abs sensor plug wasnt in all the way and that they had pushed it in. Problem solved for about a month.

Well i did my rear brakes and hads to heat the pass side rear bolts with a torch cause the one bolt wouldnt loosen. I guess i got the sensor too hot cause the abs problem came back intermitantly. I had the connector unplugged from the sensor at the time so it wasnt melted, dont know if i did some kinda internal damage to the wheel sensor. After getting the car all done and together the light came on and would go out after a restart sometimes. Oher times shortly after starting to drive the low trac light would blink after light brake application and the abs would cycle even though i was barely touching the brake and the car seemed to stumble a lil when it did this. Other times it would do it on its own with the car in park just after starting, and like you said the lights would flicker perfectly in time with the rpm fluttering and the low trac light flashing, followed by an abs inop light coming on.

Look at the underhood relay block on the drivers side behind the headlight, one of the relays got so hot it melted the cover over it and down the side next to the relay. I had that cover off when i bought the car and never noticed a problem so im guessing whatever caused it happened recently. The car has been perfectly fine again now for a week or two. Im startuing to think its a shorted wire in the abs system somewhere, hence the voltage problem and idle rpm fluctuation when it happens.

Sorry about the long post but i always try and give as many details as possible.... any of this sound like what youve been experiencing???

 

I had a clogged cat and exhaust manifold leak at the same time so I don't know which one it was but that I believe caused a hesitation at high rpms. I am fixing these two things right now so I don't know if they were the problem yet but I believe so.

 

I am tending to think that the ABS light is unrelated to the engine hesitation though. It's very confusing, i'm not sure if one got worse because of the other, or if the problem would have gotten worse anyways.

It's actually the defrost situation that confuses me most, I've never heard of anything simliar to it on the board. Why would the engine hesitate and RPMs flutter with the defrost on!? I'm going to look for shorts and anything very obvious today, but I usually don't find very much with my limited tools.

edit: BTW, it also used to do it with the A/C on, but not usually with just the vents on (you know, the face and feet vents Now it just does it all the time at high RPM

 

Update:

I just changed 5 of my plugs with AC delcos which I had laying around. Obviously, I did the easy ones

The third one from the back on the passenger side had a loose tip (it's a small threaded piece that the wire snaps onto). It had almost fallen off. So I took it for a spin after replacing these plugs and resetting the PCM by pulling the fuse. Problem seems to have gone, but I'll let you know for sure after some heavier driving.

Those 5 plugs were easy!!! I'm sure the rest won't be so fun though

 

Update for those who care:

Didn't fix my ABS light, it just came on again

I'm thinking it's a wheel bearing, my mechanic took it for a drive and thought it felt like the FR left wheel bearing was going. Of course, I can't tell, I'm too damn accustomed to the car.