Alright I'll start with when my seemingly perfect running condition FC started taking a **** on me.

Thursday afternoon, I parked my car on the grass, gave it a quick wash, started the car but the battery was completely dead. Replaced battery and alternator and it worked perfectly. Friday, I drove the car about 15 miles to Newark, the car was fine, parked it, and chilled with my friends until 4AM. Went to my car, started the car, didn't really let the car warm up, and drove it pretty slowly until it did warm up to the freeway. Right before I got on the freeway I realized there was random hesitations. I would be cruising at about 75, and suddenly the fuel would cut and then come back on again. This happened all the way back home. I assumed it was the spark plugs. I replaced the spark plugs the next morning and it helped the problem a bit, but I was still getting hesitations but much less frequently. Today John came over and we cleaned up the ECU grounding point also replaced my alternator belt. Took the car for a spin and it seemed fine. Took the car for a pull redlining 1st, 2nd, and then letting off in the middle of third, and there was no hesitation. Took it on the freeway, pulled from third gear to top of 4th, and cruised for a while in 5th and it was still good. Got back to my house and took it for a few more pulls and it was all good until I made the corner to my house. I was revving at about 5k in 2nd gear and suddenly I felt the sputter and I heard some backfiring. Took it for another short drive and I felt a little bit more sputtering. From today since Saturday morning, the hesitations has gotten much better but it's still there!

Here's what I'm suspecting:
-Timing
-TPS
-MAF
-Spark Plug Cables
-Coilpacks(?)
-Other Grounding Points Damaged(?)

Another thing I suspect is that I got this problem after I filled up with gas on Friday. The tank I had before was 87 octane mixed with a small amount of 2-Stroke. I filled up on Friday with 87 octane also but maybe I got some crappy fuel. I went back yesterday and filled it with 2 gallons of 91 octane to see if I was right about my theory of the timing being advanced. It might have been a mental effect but the hesitations seem to have gotten better. Right now I have a full tank of a weird mix of 87octane, 91 octane, and 2 stroke. So I'm going to burn this whole tank and fill it completely with 87 octane and see how it goes also.

Tomorrow after school I'll go and retard the timing back to stock, swap my MAF (I remembered when I checked the connection last time, I saw some corrosion), and re-adjust the TPS. Maybe switch out the coilpacks and whatever else could be causing the problem also. Luckily I have all these parts readily available so not a big deal.

I'm so glad this FC isn't my DD :P.

What do you guys think of this situation? Any suggestion is appreciated!

Thanks,
Rocky

 

hey rocky any difference when we cleaned the grounds?

 

Hi Guys

New to this forum and to RX-7, but I have a very nice car, FC N/A -86, and I'm having the same problems with random hesitation during load.
Today I found out that the spark plugs were loose, so I torqued them with "feeling" and the car ran great for 15 minutes. Then I stopped to top up with gas since I want to follow how much gas the car uses. After that it started hesitating again. Now I have read all about these grounds. I have found one multiple ground behind the upper shock mount. I sprayed some deoxidising liquid on it to hopefully clean off the oxide.

Where are the rest of these grounds everybody is mentioning?
Please advise. A picture (that says more than thousand words) of the engine bay would be great.
I hate electonics.

Best regards
Goran

 

Here's a link to the grounding guide: http://www.aaroncake.net/rx-7/grounding.htm

John: Nope, the car is still like that.

 

are you planning on replacing one part at a time and running the car to see if you fixed it & pinpoint your problem? or do you plan to replace and adjust everything & just be glad it's gone?

i only ask because i'm still having surging / hesitating issues with my 10thAE
i don't want to thread jack. i just want to keep up to speed with you if you solve your problem first, because maybe i'm having the same electrical issue.

i hope things go well.

 

Probably one at a time.

Today I started the car, and the cold start now idles at 2k instead of 3, and it starts surging pretty badly and I could hear the car misfiring constantly. The hesitations are still there but not constant, though I didn't put too much load on the car.

Haven't gotten around to replacing any parts yet. I'll keep you guys updated though.

Also when the car hesitates, it feels as if the engine just tries to stop turning. I would accelerate from a stand still in first gear, I would suddenly feel the car trying to stop and then go again. Pretty weird.

 

Check your fuel filter(s) too. I filled up at a station that had a bunch of crap in their gasoline, which in turn crapped up the filter by the fuel pump. Got worse and worse to the point it was undriveable.

 

that could be it, thanks for the advice!

 

Haven't had time to work on the car but today I started it in the morning. It idled at 3k for a few seconds then dropped to 2k and started misfiring continuously and then the car just died. I haven't touched the car since.

This thing is so frustrating!

 

Excellent, thanks.

Best regards
Goran

 

You must add more ground...


since the negative at the chassis and one from the engine at the chassis.



with wire of woofer of competition...

that help to me!

 

whats your exhaust ? striaght pipe? if your running straight pipe and have no back pressure your aux ports won't open up and gas mileage goes down. have you noticed anything in fuel economy?

have all the electorics you've nstalled have a ground?

 

It's a S4 RB setup. It's not from the aux ports, I'm sure of that.

 

So nobody has any idea at all?