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engine problem


Old 04-06-2017, 07:07 AM
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Join Date: Apr 2017
Location: tennesses
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Default engine problem

I got a 2004 rx-8 and it wouldn't just start (will roll start). I did the whole unflooding procedure and it started up. now my problem is it doesn't want to idle. if i take my foot off the gas then I go back to square one. Any help will be great.
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Old 10-25-2017, 09:28 AM
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Join Date: Oct 2017
Location: New Zealand
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Morning David.

I am surprised that no one has offered you information with respect to your post.

RX8's are alot more computer than car, for folks around my age.. gone are the simple sense of mechanics from the old RX7 Sav days.

If I am to understand your post, these are the things that I would be doing/looking at. each step is a suggestion and ultimately it is your car (so do at your own risk).

1: Pull your starter motor out and dismantle it, give it a good clean every component you should have PLEANTY of work space.

It is out and you have disassembled it, give the components a good clean with a can of contact cleaner or de-greaser for your mechanical components and contact cleaner for your electrical components if you want to pinch pennies.

Now that it looks like you have enough pieces to build your own Millennium Falcon, start rebuilding your starter motor, re-greasing all of the moving components and contact points of all the cogs and shafts. (I did see a Russian lad had done a video on Youtube showing all of this) ***Use Lithium Grease***

Put your starter motor back in and Test. *It should sound and feel alot stronger and better on starting your RX8 now.

2. Ensure that your car's electric system is in perfect working order/condition.

Check your Negative (earth) connection(s), battery terminals +&- , follow your battery - to where it connects to the body, clean that connection also.
**What is the CCA rating of your battery? (Cold Cranking Amps, the higher the better, ideally over 500 is ideal on a rotary), is your battery healthy?

Look for the earth for the engine, it will be a wire that goes from the engine to the body of your car also; clean both ends of this connection

Check your fuses, test and clean with your contact cleaner if you like.

3: Spark Plugs, Leads & Coils.

Always best to have help from a friend for this.
*Remember foot flat on the gas before/as you turn over the car shuts off the fuel pump to refrain from flooding, disconnecting airpump saves power.

Disconnect a lead from a coil and hold it (Using insulated pliers!!) about half an inch to an inch (8mm-15mm) away from the contact of your coil, and have your assistant wind the car over (Turn start Key for a few seconds), you should see a nice solid blue spark jump from the coil to the lead that you are holding. This allows you to see that the coil is working perfectly; do this for all 4 coils one at a time.

Next we are going to test your leads, ensure that all four leads are plugged back into their coils and remove one at a time from the spark plug end., again hold this end (again Using insulated pliers!!) about half an inch to an inch (8mm-15mm) away from solid and clean earthing source (metal part of the body with out paint).

Again looking for that blue spark.

If l that goes well, all that is left to test is the spark plugs, remember there are 2 different types in the RX8, 2 leading and 2 trailing; 1 of each per rotary housing; if you do this one spark plug at a time and put it back where you found it before moving onto the next then you are golden.

Using a 'spacer' or whatever it is called in your part of the world is never a bad idea each type (Leading and Trailing) of plug requires a different 'Gap' setting.

NGK 6700 RE7CL Laser Iridium Plug - Gap: .043" (1.1mm) *L is for Leading.
NGK 6701 RE9BT Laser Iridium Plug - Gap: .047" (1.2mm) *T is for Trailing.

*Denso produces Plugs that will work, but they run cooler and cost alot more $, this means that they are better suited for track days or racing where you are going to work the crap out of your engine and it is going to want to displace alot of 'that' heat. (this is what they mean by running cooler). Not exactly ideal for the family runner, as colder running spark plugs 'generally' require more cleaning and maintenance

Don't forget to test the same as you did with the leads, use a good 'earthing' contact and test away .

*If you want this would be an ideal time to compression test each rotary housing as you already have the spark plugs out
*if you use an old style tester, remove the valve and you will see all 3 compression's for each Rotary Apex (*point of the triangle), these should all be the same in a perfect world across all 6 Apex's, throughout the 2 Rotary Housings.... 2xRotarys (13b) with 3 Apex's each = 6

4. The rough idle could be your Eccentric Shaft Sensor, ECU settings could require resetting,

This will take ~30 minutes start to finish and you want to know that your starting issues are sorted first or atleast miles better.

Ensure you have a spare back up battery or plural, and some solid jumper cables to put your back up battery(s) into series if so required.

Put your key into your ignition, turn on 1 click; pump your break peddle quickly 20 times or more (within 6 seconds start to finish) * you will see a gauge on your dial wind up to 50% and then back to zero when you do this step correctly.

Start your car and EXPECT it to run BADLY,... you may struggle to get it to start at first (*this is why we have the back up batteries and made sure it started 'better' prior).

Once your car is running, leave it running until the ECU has made all the adjustments and it sounds great/better and has stabilised.

Hopefully at this point your annoying gremlins have now been sorted, and the RX8 runs/starts better.

Fingers Crossed for you


Last edited by Woodynz; 10-25-2017 at 09:32 AM. Reason: added @DavidC95 in the hope it would email them and let them know that their question had a new post
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