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RX7-1994 - Revs drop suddenly and engine stops - HELP

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Old 11-26-08, 04:26 PM
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Cool RX7-1994 - Revs drop suddenly and engine stops - HELP

Morning guys

my RX7 1994, Jap import, runs nice and smooth first thing in the morning. After 1-15 minutes on the road if I sit at the lights, in neutral, the revs will slowly drop down below 1000 and engine will stop. Car will then restart normally at the first go. This happens on and off, it may be at the lights or in a car park whilst trying to reverse in the middle of a gear change. As soon as I take foot off the gas the revs will die down and the engine eventually stops. I have also experienced a sudden loss of power whilst driving a few times.

Battery works fine (checked). Mechanic (RX7 specialist) has ruled out a mechanical fault and thinks it may be an electrical problem. Perhaps the relays ... He has had the car running (idle) in his workshop for hours without a problem (!). The RX7 will keep revs around 1000 and will not stall. He has checked the usual things and everything seems to be in order. Has changed the CAT converter also. However, once on the road the problem resurfaces.

I wonder if anyone has had a similar problem ?

thanks

hapbon
Old 11-27-08, 10:23 AM
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First thing I would do before I did deeper is find another computer and swap it out. Sounds like a weird problem for sure. Seems to do it under load and at idle. Funny that it would idle fine in the shop and not at a stoplight. Assuming it's the stock computer they can be had for cheap, worth a try.

Good luck.
Old 12-01-08, 10:49 PM
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im having a similar problem with my 88 fc, its fine in the morning, drive it for about 20mins and the idle drops from 1000 to like 200 and then it dies, but doesnt start back up. im in need of help too but am working on it in my shop class
Old 12-03-08, 04:44 PM
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Some more news ...
taken the RX7 to the Auto Electrician. Kept it for 2 days, tested relays and all other sort of connections. It was tested (short drive) & kept running idle speed for a while without any problems. Could not find anything wrong with it, except slight overheating at idle. So ... I picked up the car (and was lucky enough he did not charge me anything ... bless his car emissions), drove 50 meters down the road, stopped at the red traffic light and within 1-2 minutes the engine had stopped ! &%&$#$#@.
Going back to Mechanic now, he will put in a spare series 6 computer and see if it makes any difference (why on heart didn't we try that in the first place you ask me ...) ...He is the Mech and he races them ...
Will post more as the saga goes on ...

Thanks for your replies ...
Old 12-03-08, 05:49 PM
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check your compression in your rotors. he may have to replace one or 2 if that, make sure u dont have a vacuum leak and if u have a power FC check the voltage. off is should be at around 11.5 - 12.4 volts, running it should be around 14 volts. also how many miles is on the car?
Old 12-12-08, 07:50 PM
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More to the mystery ...

First of all the car has 59,000 Km on the clock (for TmoneyRX&tt). Items mentioned in your post were all checked and were fine, but thanks anyway.

Some more of the same I am afraid. I took the car back to the Mechanic as the spare computer did not seem to help. I think he's still scratching his head ... and I am lost as to what to do next. Anyway we continued with the elimination process. I pointed out the car seemed to be overheating so... a quick check to thermo, radiator etc. All looks OK, Temperature running idle for 30 minutes in the workshop was fine ((car did not stop once !). The radiator was checked by a specialaist and whilst still OK it would have needed replacing in the near future. (plastic inside alluminium tank breaking up) so in goes a new alluminium one, Thermo looks good but we put a new one in just in case plus new caps, bleed the radiator, replace liquid, the usual. Car runs fine in the workshop at idle speed and temps are OK. Test drive was OK. So before I take it back Rick replaces the idle speed motor too even though the one on the car looked OK (spare parts from his shop).

So I take the car and it runs beautifully for a few days till this morning. I stop at a set of traffic lights and before I get a chance to do anything about it ... DEAD !

&%%$#$@!#@$$

Luckily it restarts fine and I don't get run over by the motorist behind me.

I keep on driving but it just does not feel the same. As soon as I take off the foot off the gas the idle speed indicator overs around 1,000rpm, and slowly decreases (600rmp) at which time I am forced to put the gas back on before it stalls. One annoying thing (on top of dying) is that at idle speed the engine seems to vibrate a bit , not sure how to describe appropriately ... as if it is loosing a beat or two, or perhaps the gas is not getting through .. (but the fuel lines all checked OK).

Time to trade in .... I guess ... running out of savings.
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