we changed my timing and got it to spec. It is still idling like a fat biatch. The car is still running rich like Bill Gates action. What sensors should i check that would be making my ecu run the car rich????

 

qquack

 

TPS??

 

i dont htink its the TPS
the idle is like, 'vroom, fall.. vroom, fall... vroom, fall... vroom, fall..."

 

02 sensor

 

a/f gauge is working fine. that should mean that the o2 sensor is working correctly right?

 

gotcha...that makes sense to me...just throwing out ideas.

 

If it is making thats described sound real evenly even once its warm, then i have seen that be TPS my 87 base and a friends TII.

i hate that noise

 

i didnt read the description you gave up the idle...unless you've checked it and its fine...i would defintely say TPS...try unplugging it and see what happens...or set it with a DVOM

 

I also think it could be the TPS. I had a coworker whose '91 idled just like the way you described. It was diagnosed by the dealer (this was under warranty way back when) to be a faulty TPS. Good luck

 

??

 

How about this. One of your Lead wires is bad. Take a timing light, and put the inductive clamp near where the plug wire connects to the coil assy. At idle, look for a consistent flashing. Compare it to the other wire.

I know that sometimes if the clamp isn't held in a certain way, that you will see intermittent flashes. So don't be misled. The reason I mention this is that I was messing around with the timing on the 86 yesterday and notice that Lead no. two was barely flashing no matter how I held the clamp on the wire. NO. one flashed very consistent. I pressued the wire where it went into the coil assy and it flashed consistently. Swapped wires where they go into the coil assy and the BAD wire got a little better. It does not seem to be whether the bore is clean enough or if the wire is going far enough down the bore. Thats just fine. I think I have a bad wire.

So maybe thats why you run rich. A plug wire. Most likely a Lead plug wire?????????? I''m not a big fan of a Trail wire giving you the symptoms you have.

 

BAC (or the ECU transistor that drives it) (or the connector).

 

Check the clutch switch and BAC. Whenever these go bad, I've seen '7s do the "vroom...(fall) vroom..." phenomena.

 

I've got the same problem and it's driving me insane, since I'm about 1500 miles from home. Tomorrow, she goes to the shop... I'd hate to get stranded in the boonies!!

 

Mine only does that as the second warm-up phase. Like first, i start my car (in stupid-cold weather) and it's rough, so i blip the throttle, and it shoots to aobut 2000 RPM for a couple minutes, then it goes down to 1500 RPM and does the vroomfall syndrom. After it's warm my car idles like a dream, right at 750. Weird, huh?

 

well, i have thought about that too... infact, we had the timing light plugged onto the leading (number 1) wire last night when advancing the timing (timing was retarded about 5 degrees, so we advanced it up to meet the pin) and we got consistent pulses on leading plug #1. so are you saying that i should hook the timing light up to the second leading wire and see if it is a consistent pulse?

i took my crank fan off just to get the car to run a little warmer while i was idling in the cold. the temp got up to about half way and the car was still doing the ole "vroom drop vroom drop." sometimes it does it and sometimes it doesnt... i guess i'll go and try swapping the plug wires around and see if that fixes anything.
any other ideas HAILERS?

 

i dont have those warmup fases cause i took my emissions nest off and the airpump and all that jazz. i just kinda know its warm when the gauge is above the C.

 

ok HAILERS, quick question..

now that i have my crank fan and fan shroud off, i can see the whole radiator and i have some room to work...
now that i have all this room, i have found that my water temp switch (drivers side bottom corner of the radiator) has one of the contacts broken off and is obviously not doing its job.

the question is, could this be part of my problem? what would happen if this water temp switch were to stop functioning correctly in a totally normal S4...

 

Uhhhhhhhhhhhhh. If broken, it will disable the 3000rpm start up when cold. And has an effect on the Relief solenoid and errrrrrrrr, I done did forget what else. I'll get back. On the whole I don't see it being your running rich problem. The water thermo switch on the back side of the water pump housing WILL make the car run rich though, if broken, disabled etc.

Back to the water temp switch on the bottom of the radiator.....the only other thing I came up with is that if the water temp is below 65 degrees, it will make the relief solenoid open and dump air from the acv when the rpms are over 1200 rpm.

Here's the deal. When the water gets over 65 degrees, the switch *makes* and completes a circuit. If you were to jumper the connector that goes to the water temp switch on the bottom of the radiator, you could see if the water temp sw is causing any of your problems. Most the time the water is way over 65.

Water temp switch on the bottom of the radiator is only found on series four.

Seems strictly emissions related. I see no other use described in the fsm.

 

can you scan me a picture of the water thermo switch? i think that very well may be my problem

 

While looking for a picture, I found this thread....https://www.rx7club.com/forum/showth...ter+and+thermo

 

Am I understanding correctly, that the water thermo sensor can affect the idle?? Is this why the idle surges during warmup, and bucks wildly at low rpms?? Because, my car no longer has the couple minute high idle while cold either. Both problems started at the same time....

 

dang should have known i should had taken apic when i change my water pump, well the water thermo sensor is located on the back of the whole water pump assembly. this not a good pic but i took this when i re-did my vaccum lines..

it's under/behind the alternator, sorry for a the poor *** pic.

 

i think this is a better pic