Ok guys..... Some of you may remember my thread below from about 2 months back, but if not I have conviently placed it below.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/problem-when-car-traffic-help-please-671839/

Any who, I finally got around to replacing the Air Intake Temp Sensor, and thought everything was ok........NOPE!

I only test drove the car after I replaced the sensor last weekend, and during the test drive it drove amazingly!! So today when I got off of work I picked up the car to go get a new brake tag. It ran like a dream, and about 5 minutes into the drive my tach and speedo started working again. They have not worked since the car had the traffic problem the first time. Needless to say I was very excited. Well, about 5 more minutes go by and I get into some traffic. After moving slowly in the traffic for about 3 more minutes it starts happening again!!!! As soon as I give it a little gas I get the loping vrap vrrrrap vrrrrapappappp pap. DAMN IT!!! So I immediatly check all the gauges. Vacuum good, fuel pressure good, temp good, but something wasnt good. Right at that moment when it happened again the speed and the tach stopped working again. Is this a coincedence? Maybe, but doesnt it seem odd that right when they start working again the problem comes back? Could it be a sensor that controls the gauges is also causing the issue with the car not running correctly?

Long ending kept short:
I pulled over to unplug the AIT because I thought maybe I replaced it with a bad one, and last time when I unplugged it I was at least able to drive home......not this time. Had to call to tow truck, and now she is sitting safely in the garage. BUT still not running....again...and again.

Any who, if any info is needed please let me know so we can try to trouble shoot this thing. I am pretty much at a loss, and dont know what else to do.


thanks guys,
-josh

 

Are you getting a CEL at all? Have you tried resetting the ECU? Are you running any cats?

 

Ok, sorry it took me a day to respond, but I got anwsers for you! haha

Have I reset the ECU? Yes, and have tried two different ECU's. It has done this with my stock ecu as well as me M2 ecu

Am I getting a cel? YES I pulled the codes and they are as follows....

After reseting the ECU when the engine was cold,

6- speedometer sensor
12- throttle sensor full
18- throttle sensor narrow

I know that my TPS has been off and I am soon going to adjust it, but I really dont think that it is causing this problem so I have been thrying to hunt out the main problem lately.


After resetting the ECU when the engine is at operating temp,

12- throttle sensor full
18- throttle sensor narrow
38- accelerated warm up (removed so makes sense it is throwing the code)
42- Solenoid valve pre control (removed)
43- Solenoid valve waste gate (removed)

The waste gate and pre control were removed after this problem started, so I do not believe it would be either of those.

And for the last question....am I running any cats? Yes, I am running the primary cat because I do not believe the M2 ECU is tuned for open and/or high flow cat.

Thats it!!! Nothing that I think would cause this problem!

If you have any thoughts please let me know.


thanks,
-josh

 

The fact that your dash gauges started freaking out signals that the problem is electrical system-based (as in a ground fault somewhere in the wiring). If a ground fault in the TPS line suddenly causes the signals to go crazy, then any time you move the throttle past a certain point, the confusion will cause the ECU to just shut everything down instead of going into limp mode. That's my theory based on what info you've provided.

 

Well I was mentioning the gauges because I didnt want to leave anything out, but my gauges have always been screwy. I have the typical rx7 "bouncy gauge" problems that you see all the time on here. I am not sure that proves it, but I will agree that it is electrical. Now if I could figure out where that would be great. I guess my next step will be to check the TPS, reset it, and check the line.

 

If your TPS is in check and you are still having this problem, i would go ahead and go the route Kento has explained.

But im pretty sure it is the TPS because if you search under people have problems related to yours, the TPS is almost always the culprit.

 

Ive come 2 find that when tha tps is off, tha car acts funny in seemingly unrelated problems. Before adjusting my tps, I ran into boost problems where tha 2ndary would kick in at 6500, backfires, looping idle in nuetral when warmed up, blah blah blah.

Tha only thing I did was adjust tha tps (never touched anything related to tha boost issue) and it was ALL fixed. All I could do was scratch my head..then enjoy tha car again. Good luck.

 

^ Alright then guys, I will tackle the TPS adjustment, and we will go from there.

wish me luck, and thanks again for all your advice guys!!!!


godspeed,
-josh

 

OK, adjusted the tps. It was a bit off. The throttle response and acceleration smoothness is much better, but it didnt fix the problem when the car got hot.

any other ideas fellas? I appreciate all the help prior guys!!!

-josh

 

Did you reset the ECU after you adjusted the TPS?

Also did you pull codes again after the TPS adjust?

 

I reset the ecu, but I didnt have time last night to pull the codes again as it was quite late when I finished, and testing.

 

As I stated in my previous post, you need to check the wiring leading from your TPS and loom itself. You have a ground fault somewhere that is causing the ECU to get confusing signals, which results in shutdown (could possibly also be the cause of your instrument gauges occassionally going wacky).

 

I did check, but I didnt find any faulty wires, and when I was setting the TPS i didnt have a loss of voltage...even if I moved it around to try and get a funky reading. I am going to continue to check around just like you suggested though.

 

The TPS signal travels through the wiring loom to the ECU. Just because you checked up at the TPS doesn't mean there isn't a ground fault somewhere along that line. Unfortunately, tracing a problem like this takes some major patience and time. You might try checking all your fuse and relay boxes (and the lines leading to them) as well.

 

^ Good call!!! I will do this, but I feel this problem is going to be a long drawn out issue.

 

You need to plug the two turbo Solenoids that you removed back in or install a resistor in there place. They are putting the ECU in to so called "limp mode".

Even if that is not the only problem, the car will not run at higher loads with those two codes.

The ECU does not have a "just shut everything down" mode, no matter how confused in gets.

Paul


.

 

The car ran like this with them plugged in and with them unplugged. These solinoids are doing nothing with the way my vacuum diagram is run.


I ma running version 2 listed in the pic below, so I am not sure how that would effect the vehicle. People remove these all the time when they do vacuum job simplification jobs/ etc.

 

What Gadd is saying is that if you remove a solenoid from the system, you need to leave it on the rack still connected to the electrical system or install a resistor in its place (to fool the ECU into thinking it is still attached), otherwise the ECU senses a problem, and in some instances, triggers it to go into "limp home" mode.

The fact that your problem (where the engine eventually stops running) manifests itself as the engine warms up leads me to believe that a ground fault somewhere in your wiring related to the TPS. Once the ground fault occurs, the signal going to the ECU is so off the charts that it doesn't know what to do with it, even in limp mode. That's my theory anyway...

 

Yeah I understand that, but through my searching I have never found this to be a problem for anyone else who has removed these. Plus it did it with them plugged in, and unplugged.

This is what I am thinking is the most probable at this time. I am still hunting for the issue in the TPS lines. Hopefully I can find something there.

 

I'm sorry I was mistaken. I reviewed the service points section in the FSM and it's only the charge control solenoid that will cause "limp mode". I thought it was all of the turbo control solenoids.


Paul

 

man no problem!!!! thanks for trying to help me out!!!

 

I can eliminate one item from your issue. Since my speed sensor is intermittent I can say for sure the car will still run fine even if it doesn't detect any seed indication from the sensor to the ECU or gauges. you need to put a meter on your ground wire from the TPS to the chassis and see if your loosing it when the car has warmed up.

 

Good call jack. I will do that as soon as I get home!