I have a 91 Vert that went to the shop not too long ago. Unfortunately I am one of those people that loves to drive my RX-7 but doesn't have time to learn how to do all the work on it. So I am a bit at the mercy of the mechanics on some things. Anyway I just did the coolant seal fix not too long ago and the car was running like crap when I got done. No more water issues but the car would not accelerate and smelled as if it was running extremely rich. So I took it to a mechanic to see if he could get things adjusted so I can pass emisions. He came back and said that the computer (ECU I assume?) was bad so he couldn't get it tuned.

So I have two questions:

Is it possible that there is a different problem that would make him think it was a bad computer?

Anybody have suggestions where I can get a new/used computer, and if so how much would it cost approximately?

Thanks in advance,

Devdude

 

Oxygen sensor some times causes that when they go faulty. I would change the O2 sensor then pull my main fuse and leave it out for 5 minutes then put it back together. I bet it will run fine. O2 sensor costs $100 au here. Also a faulty TPS can cause some unusual faults.
Michael Smith

 

i think your mechanic is full of it.

everything needs to be adjusted to spec for the variable resistor to work properly to change the idle mixture.

i passed emissions without an O2 sensor even hooked up....

if the MAF screw has been tampered with though it is almost impossible to set the MAF back to it's original setting so if the cap is missing off of the MAF then it probably has been tampered with and could also be the cause.

 

Yep, your mechanic is clueless.

a 91 vert will have a ECU that you can pull the codes from very easy and see what the problems are. Any even halfway decent mechanic know how to read OBD1 codes.

ECU failure is somewhat rare unless the mechanic himself (or herself) blew it up testing with a test light.

 

used computers (ECU) are avalilble on this forum used and usually on Ebay-you just need to know what model you need. After having gone through this mess myself for the last month, I finally figured out what Icemark said "its probably not the computer". The ECUs I looked at run anywhere from $30.00 to $100.00 on ebay-Mazda wants about 1000-1500 for a new one. If you need one check the for 2nd Gen for sale section in the forum

 

If you just did the coolant seal "fix", then you should be more worried about getting a new engine in there. The "fix" is only an emergency stop-gap measure to be used in situations where you need to extend a water pumper's life for one reason or another (ie. to get home, finish a race, etc.). Unfortunately, many people publish the steps to do this "fix", and neglect to mention this simple fact.

Your problem MAY be due to the coolant temp sensor. It might be totally coated in the sealant crap, and thus not getting much of a reading. This will cause the car to run crazy rich.

 

Thanks for all the input. It seems pretty much unanymous that maybe I need a new mechanic!! If anyone knows of a good mechanic in the Nashville TN area please let me know. Aarons thought on the coolant temp sender makes a lot of sense. I am going to try and change that out first and see what comes of it.

Thanks again for all the awesome input!!

Devdude