Hi, this is a repost i did last week in the general category...

Hello,

I just picked up my new 85 gsl-se yesterday and went on a 2 hours road trip. Everything went find until the end. Suddenly, the engine lacks power and will not rev over 2000 rpm, sometimes 3000rpm. It will not accept to move under its own power. The only way i could get back home was to shut the engine and restart it... then i could floor it for about 10 seconds, operating normaly and it would do the problem again....

Reminds me of a old airflow meter problem i once had on a efi porsche 944. It would work on the idle and partial thhrottle setting but not on the full throttle setting. Or could it be the computer? I have a s[pare one i could try..

Please help me with your insight. I wanted this car for 15 years, finnally get it and it dies on me. I was just telling my wife i was happy that for once, a used car i bought did not brake down the first day... 15 seconds later, it did

I was thinking about trying to clean and lubricate the AFM... any ideas or experince




...So I now had the car for one week... what a great car!
I did not do the problem again until tonight...

I visually checked all the wires under the 2 storage bins... everything seems find, no oxydation.

I swaped the ecu for another one. The problem is still there...

I checked the engine running in total darkness... I see no fire jumping out...

The problem is still the same: at idle, you can here something is not right, not smooth enough. If I give gaz, it rev to about 2000rpm and then goes back to idle. then revs, then idle...

If i kill the engine and start it again, then i have power for about 5 seconds.

I am i need of ideas...


I just discovered the FAQ and everything about idle problems common to this car. I will slowly try to check everything as i have little mechanical experience.
The mitch technical bulletin seems to have dissapeared from the site...

 

as you said the problems not just yours, mine was similar, ive calmed it alot through tinkering with it because im too lazy/broke to buy the tps adjuster light from mazdatrix. here are some links of found on the subject:
http://www.nellump.net/peri/epi/firs...gslseIdle.html That one seems to be the best ive ever found.
http://www.wankel.net/~krwright/cars/rx7/manuals.html and of course the FSM

ps go to mazdatrix.com and order the TPS adjuster light, it will be a big help

 

" im too lazy/broke to buy the tps adjuster light from mazdatrix." Make one yourself for about $7.00.


When was the last time the 7 had a tuneup? Check for spark when that happens again. Fuel pump cutting off? How is the tach reacting? The Doc will give you some good advice.

 

The TPS will not cause these symptons.

Check list.
Start engine and let it get to operating temp. When it acts up, start with the following.
#1). Verify that there is spark to the leading plugs.
If the trailing was out the car would just die since the fuel pump circuit goes thru there.
#2). If there is spark at the leading side. Perform a compression test.
#3). If compression looks good and spark is at leading side at that time.
Perform a fuel pressure/volume test.
If you are not familar on how to perform the compression test the test procedure is in the archives I believe on the 1st page.
The fuel pressure/volume test can be found in the FSM.
Report back after the above results are in.

 

RX7doctor what do you mean if the trailing was out of the car?

 

trailing igniter triggers the fuel pump

 

Well I completly cleaned and lubed the airflowmeter yesterday. It looked like it needed it. I only use the car once of twice a week for fun so i'll be monitoring the problem and let you know.
I feel I now have a lot of info thanks to you guys and this wonderfull forum to try to tackle this problem seriously.

I'll be in touch

Au revoir!

Fred

 

Brandon, you misread the statement. It states if the trailing was out, not out of the car.

 

Well, it seems like I cured the problem...

After lubrifing the airflowmeter, I found a small vacuum T that was broken. Fixed it and the car has been trouble free ever since. I even took a 200 kilometer ride without even a sign of trouble. Since then, I reoiled the k&N air filter, changed the differential oil with some Red Line 75w90 gear oil and changed the transmission oil with Red Line Mt-90. I also tried to flush the braking system but broke a bleeder valve while trying to loosen them up.

I know, you will all tell me to buy the speed bleeder valves but I decided not to. My wife is more than happy to help pumping. Looking at the black dragon catalog, I saw that they sell the exact same bleeder valve from 79 to 92 for the front and 79 to 95 for the rear. So I went to my local mazda dealer and ordered some 1992 valve (sorry, the 1985 parts number are on microfilm and we do not have it anymore I.E. The guy is too lazy to check)

6 canadian $ for each front one and 4$ for the rears... total 24$ tax included. I guess I will heat up the valves before trying to unscrew them. and if i break some more, I will already have replacements.

That should do it.

 

The vacuum tee that you found. Was it the one on the firewall on the passenger side? Goes to the 2 solenoids.

 

I have a hard time finding the names of the parts it goes to but i will try my best. I located the 2 solenoids you are talking about. Connected to it is a vacuum tee. Left of that vacuum tee is another one. Thats the one that was broken. It is a inverted tee actually. The left tube is connected to a little (about 1 inch * 2 inches) part (???) that is in the very left upper corner of the engine bay (passenger fender-firewall corner) It cannot be more in the corner than that... The right part goes to the other T towards the solenoid. Finally, the broken part was the top one that goes to what looks like the cruise control motor (???) It is in the upper passenger side of the engine bay, with a metallical wire that goes at the same place than the throttle cable. I cannot locate the name of that part in the shop manual.

I know I need to study my stuff...

I'm back from the dealer, with my new bleeder valves. It seems that I was right about the 79 to 92 being the same... Even more, the front and rears looks identical... I could have saved 4 big dollars...! ordering 4 rear ones...