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S5 GTUs Running after 10 Years - Idle issue?

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Old 04-02-16, 02:11 PM
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VA S5 GTUs Running after 10 Years - Idle issue?

I got my newly acquired 89 GTUs started today. The car had been sitting for 10 years so I was very concerned the engine was dead.

I pulled plugs, added oil in the chambers, new fuel pump, fresh gas, and oil change.

I could not get the starter to turn over. I tested with a voltmeter and verified the starter cut relay was dead. I put a jumper wire in the starter cut relay socket but still couldn't get it to go. I continued checking for voltage at the clutch switch and finally decided that switch was dead also. I installed another jumper and the engine cranked just a bit.

I quickly shot a little starter fluid into the air inlet hose and she fired. Re4ally rough for a bit and dropped an enormous amount of blue smoke as the oil burned off. Engine sound stabilized a bit and it steadied at about 2500 rpm.

That's the problem. Idle speed remains at 2500 rpm even with the engine warm. At times it will burble and drop back to 1800 before climbing back to 2500.

I'm very familiar with Ford products and their idle speed controllers. I didn't see one on the RX7 unless it is buried on the back side of the intake. How does the RX7 control idle speed?

I have to replace the clutch master before I can take it for a spin around the block.

Thanks for the site!
Old 04-02-16, 02:56 PM
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If its been sitting for 10 years, you really should go through and replace the vacuum lines, you probably have a vacuum leak

Another good possibility is the thermowax is stuck and keeping it high, i'd say clean the throttle body and flush the cooling system as well
Old 04-02-16, 04:28 PM
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Press upwards on the front throttle linkage which closes the throttle plates and the ensuing idle should drop some at least. The fast idle cam mechanism on the rear throttle linkage has a metal rod which sticks out further as the engine warms up. The rod presses against an upside down screw which is part of the rear throttle linkage which helps to close the throttle plates, and that too drops the idle speed. If the engine is truly cold just see how much of the rod sticks out and as the engine is started and idling/warming the engine the rod should stick out even more.
Old 04-03-16, 09:39 PM
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Thanks guys. I'm cleaning and lubricating and things are getting better on the idle front. However, out of the blue I had a problem getting it to start. I finally pulled plugs and they were coated in oil. I cleaned them and she fired right up but put down a significant amount of blue smoke. The smoke only lasted about 20 seconds.

During the day I've wandered back out and started the car several times with no issues and no smoke. I've spent time searching the site and it seems the most likely thing is oil control rings.

Does that seem reasonable?
Old 04-04-16, 10:23 AM
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If it was oil control rings it should be smoking constantly, but, there IS a chance, rubber sitting for 10 years can go bad. If i were you, get the idle situation figured out, and run it through alot of warm up cycles, just fire it up, let it idle until its up to temp, than shut it down, this will help blow the 10 year old gunk out, and get the seals expanding and compressing again
Old 04-04-16, 10:43 AM
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I'm still messing with it. This morning was a no start. I pulled plugs and they were covered in oil. I cleaned them and it started but with that huge cloud of blue smoke again. The smoke lasted for 20~30 seconds.

I just went out and started the engine after an hour. It fired right up with no smoke. The recurring oil fouling after an overnight shut down has me baffled.

I now have a stable idle at about 1400 rpm. Like I said I'm still cleaning and checking on those things.

I'm off to the parts store now as the alternator belt snapped. I've also picked up a coolant leak under the radiator. Time for new belts and hoses. I hope the radiator isn't leaking.

I've also ordered a new clutch master cylinder as the pedal is on the floor and bleeding doesn't work. The MC will be here tomorrow.
Old 04-04-16, 11:09 AM
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Idle speed should be close to 750 rpm.
Old 04-04-16, 04:55 PM
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Update....

Yes, I'm a Newby....

I installed the new belts but decided to wait on the hoses and concentrate on getting it to run. I tried to start it with no success. It just whirred and would cough at random. I decided to pull out the timing light and check for spark

I had spark as follows:
front coil only the left side would fire
Rear coil- the left side fired occasionally, the right side not at all.

Not good. (Note to self - I need to do some research and see which plug connects to which coil...)

So, I started checking wiring. I disconnected the coil supply connectors, cleaned those and got nowhere with that. Some more looking and I realized there is a black plastic cover over the end of each coil. I popped those up and noticed the wiring actually connected to the coils with a spade and nut on a stud. For lack of anything better I disconnected and cleaned those.

Voila! The timing light showed spark on all plugs. I put the fuel injector fuse back in and cranked it. It fired more but wouldn't start. I could also smell gasoline. Ah! it may be flooded cause of all the previous cranking attempts. Ford EFI is set up that in case of flooding flooring the pedal shuts the injectors off. I don't know if that is true with a Mazda. Anyway, it cleared out and fired up.

After it warmed idle went to about 800 rpm. Now the question is will it start cold? I'll find out tonight or tomorrow morning.

Also, it now appears the radiator is leaking.....
Old 04-04-16, 07:04 PM
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S5's are set up to kill the injectors with the pedal floored, not s4's, so you got lucky lol
Old 04-04-16, 09:07 PM
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VA

It's getting better. Here are two pictures. Engine compartment as purchased versus today. I wish I had the stock air cleaner box.

Next up if the starting is fixed...Trying to buff the red back into a recognizable color
Attached Thumbnails S5 GTUs Running after 10 Years - Idle issue?-img_5837.jpg   S5 GTUs Running after 10 Years - Idle issue?-20160404_095031.jpg  
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