nima_taba

I put up a post a few weeks ago about the pause in acceleration at about 3800 rpm on my 88 N/A. Someone recommended that I put in an additional ground wire from the negative battery terminal to the chassis. I just read another post "Enough is Enough" which also recommended adding another ground for a multitude of problems.

What does adding another ground wire do, and will it help with my problem?

Thanks,
Nima

fastrotaries

Your O2 sensor is grounded through the exhaust, so make sure that your exhaust is grounded, that cured the problem you're having on my TII

HAILERS

The ground for an electrial device is just as important as the voltage. If you will look at the factory servicew manual electrical schematic Bb-2 for a 87turbo, you will see that the ground for the ATP sensor, airflow meter, intake air temp sensor, water thermo sensor, pressure sensor, variable resistor, throttle sensor, and ecu at pin 2c, are all spliced together. As in shared ground. I've had to splice a engine harness together where Richard Head had cut the harness to get the engine out, and I can assure you that those grounding splices exist just about where the harness crosses over from the chassis to the engine. Mazda had a service bulletin that had the mechanic add a extra ground at the boost or pressure sensor if you will, to ensure a better grounding circuit. Its easily accessible being on the r/h strut tower. Brown wire with black stripe. Adding even more grounds from the engine to chassis can't hurt, can only help. Then again you problem may be some other thing all together. Just wanted to point out the shared grounds of those items listed above. Should add that if you don't know a lot about fuel injection, like me, then read this following url http://www.howstuffworks.com/fuel-injection.htm and click on *engine controls and performance chips*. You'll see why the picked the pressure sensor for the extra ground. It measures how hard the engine is working i.e. load.

Chance

I've never heard of that. How did you go about doing it?

nima_taba

So what should I do to the brown wire with the black stripe on the RH strut tower?

Sorry, I'm a bit slow!

Thanks,
Nima

HAILERS

Go to this site http://teamfc3s.org/main.shtml Look at FAQ. Look for 3800 rpm hesitation. The wire needs to be grounded. Its brown with a black stripe. There is a free factory manual at http://www.iluvmyrx7.com it can be downloaded for freee. It has the wiring schematics also. Section 4a deals with the fuel system, timing etc.