Mazda Rotary Club

Chaps
         I need a bit of help from those with more rotary experience than me. My \'92 FD has been running fine until today. I drove the 65 miles to work today with no trouble. When I came to drive home, I warmed it up very gently as usual. Then as soon as the boost guage got to 0 bar, the engine cut  dead. It idles and runs as normal whilst there is vacuum, but it cuts immediately there is any hint of positive boost. I saw one thread suggesting that it might be one of the control valves. Any other suggestions before I start pulling the inlet apart? Plugs? HT leads? I ruled those out, since I would expect a more progressive failure.

BTW the engine is standard except for HKS cat back. There are no warning lights on, no unusual noises and temperature is normal.


Thanks
Keith

Despite taking the solenoids and pipes apart to check everything, I didn\'t manage to fix anything last night. I tried again today, and looked at the check valves. These all seemed to be fine. I checked the secondary throttle actuator which seemed fine too. In desperation, I disconnected the battery for a while to reset the ECU. I tried the car after that and it works fine now!

I have no idea what fixed it, but my guess would be that one of the check valves was leaking, and I blew some dirt out. It probably won\'t be long before it happens again, so I\'ll try one thing at a time next time!:)

It sounds like your computer has gone into default mode,  first disconnect the battery and hold the brake pedal down for 10 - 15 seconds.  Then reconnect the battery, this resets the ecu.  

The only you might have is whatever made go to default mode, may still there and it might do it again.  You might find that playing with the solanods etc has cured the problem and you just to reset the computer as above.
regards
tony

Default mode is a built in safety mode to stop it blowing up if it thinks something is wrong.

It\'s broken again. Only this time I was 200 miles from home, which was less than convenient. This time I tried the best that I could given that I had few tools with me. Disconnected the battery, turned on the lights, pushed brake pedal, reconnected battery - no difference at all.
Removed the upper check valve on the manifold and blew through it - it seemed fine. No change. Then I tried the bigger valve ( with integral filter? ) which seemed OK too. This time I had boost as I rejoined the A12, but only until 3rd gear, when the fault came back. I then removed both the bigger valve and the remaining small valve, which both seemed OK. No change so no boost all the way home.
Sorry to anyone stuck behind an FD at 40MPH last night!

Ive had the same problem since i did my vacuum/coolant hose replacement job, whenever the car goes to boost its splutters and dies, i went through all the procedures suggested including the batt disconn thing.

SO ive bought a new engine wiring loom (40 quid from ross@dragon) that connects to all the solenoids from the ecu, as this is the only thing left i can think of, it sounds even more likely in your case as the problem is intermittent, so their maybe there is a poor electrical connection somewhere in the loom.

Im fitting it tomorrow (if it arrives) so ill post details if this fixes it!

( i also bought a new turbo precontrol as well )

kbareham
I would suggest having a look at the actuators on the turbo pack. Check the hoses on the actuators. Check the rods are on and the circlips are in place. Not the easiest of jobs.

I had a rod come off the Precontrol and catch on the arm for the pre-control gate. The car would boost on the primary and then nothing at the transition, if this happened then I would have no primary or secondary for a couple of minutes. Then I was back to square one...no secondary.

A good site.

http://www.autosportracetech.com/RX-7/rx7stuff.htm

Good Luck ;)

If you really are stuff, get it down to your nearest expert and get a good check done, as it may be a combination of faults, plus those in the know will find the fault quicker and remove more effectively.

Gurj

My nearest expert is 50 miles away, and i cant get over 20 mph in my car, so a 185 quid trailer jobby doesnt take my fancy.

Fairplay chap.

Its just sometimes what may take us ages to find the guy in the know finds it straight away!!!

Hope it works out mate.:)

it\'s not a bad thing being eager to learn & trying to know the answers
Si (slack SOB with no money & even less know how......lol)

are you calling me a swot si?:p

lol no mate was just saying it\'s a good thing to learn stuff about yer car & such like yerself & from those with knowledge on these boards & especially when it\'s essential for either £ saving reasons or in your case lack of alternatives given yer plight
Si
PS teachers pet pmsl

Sound like I\'m not the only one getting frustrated by this type of problem. Im in the garage scratching at things to look at next.

I went round to see the chaps at RX motorswho suggested a few thigs so-
Today I have changed the plugs - which needed doing anyway. Then I took the upper manifold off and replaced one crushed hose and two check valves. I took the charge control solonoid out and checked that - OK.
And guess what. Still no boost. I have noticed that it will boost if its cold. I can drive about two miles and although it is cold, I let it go just positive at 2500RPM, and it pulls like a steam train. Until its warm, and then it 40MPH everywhere again.

I\'ll keep at it and report any findings.

So I thought that I was making logical progress when I tee\'d the boost guage to the vacuum side of the charge control valve, at the solonoid end of the pipe. Went out to see whether the vacuum disappeared when the car cut out - and it has run perfectly ever since, even now everything is back together as before. It seems to be very difficult to track this one down.

Keith

:(

Long shot, but check the hoses in and out of your intercooler, they go soft with age and collapse under boost. You may need to take them out to give them the squeeze test.

Max