RCCAZ 1

iTrader: (10)

Everyone,

I'm posting this for a friend of mine. Within the past 6 months he had upgraded his fuel system by installing 1300 cc side feed secondary injectors from RC engineering (stock 850s bored out), had the car tuned by Steve Kan, and the car was performing flawlessly.

Anyway, about 3 months ago one afternoon he stopped at a convenience store to get something and when he came out the car started but ran rough as if it were only running on one rotor and after a few seconds the second rotor would kick in.

This continued for a couple of start cycles until finally the car would not start at all. A local Mazda mechanic performed a compression test and reported that he could not even get the Mazda compression tester to give him a number on ANY rotor face.

In talking through this issue with Steve Kan his belief is that the car probably had a stuck injector that flooded the combustion chamber with too much fuel, thus overpowering the injected oil from the OMP and causing excessive carbon buildup (i.e., stuck Apex seals). My friend has tried putting ATF in the motor, but in his words, "the engine still just doesn't sound right compressionwise when I turn it over." He's tried pushstarting it to no avail. Anyone have any other ideas on what to try? Should he soak the damn thing for a couple of weeks with ATF? Any other fluid he should try?? Is it possible that the seals will NEVER come unstuck? Any tips you can give me to forward to him would be greatly appreciated!

RotaryResurrection

iTrader: (8)

Change the plugs..one is fouled from the excess gas, and the car won't start with several problems at once.

He could have an injector still leaking in too much fuel, in which case the car won't fix itself and probably wont start and run normally...someone is going to have to get in there and find out. I suggest removing the fuel rails from the engine/intake but leaving them hooked up to the fuel lines; jumper the fuel pump in the diagnostic box, turn the key on, and watch for fuel leaking out of the injector(s) over a 15 minute time period.

I really doubt this has much to do with apex seals or carbon buildup. On the off chance that there is no fuel leak and the plugs are not fouled, this could also be a coolant seal failure, letting water into one chamber on shutdown, flooding it out, and making it hard to restart due to the water washing the oil off the housing. This would probably not manifest itself on both chambers at the same time, though.

RotaryResurrection

iTrader: (8)

Also, have him remove the egi fuse, remove the lower plugs, crank the engine with the throttle open several times of several seconds each. This will blow out whatever is in the chambers. Inject a bit more motor oil or atf, install a new (or known working used) set of plugs that have not been subjected to oil/atf or gas for extended periods of time. Reinstall the fuse and see what you get.

Further problems indicate a fuel or coolant leak internally.

RCCAZ 1

iTrader: (10)

Kevin,

Thanks for the ideas. I'll let you know if we make any near-term progress. He's gotten very discouraged and is getting married within the next year, so his current focus and funds are going towards the wedding. I'm just afraid if he can't figure it out soon the car will sit for more than a year before he get's back to it and by that time the internals will be froze up from sitting. We'll see, and thanks again for your suggestions!

POS7

No offense, but you should be able to do this yourself as opposed to waiting on someone else. My .02

RotaryResurrection

iTrader: (8)

ON the off chance it was a water flood, you/he had BETTER take care of this quickly. IF water sits pooled up in a combustion chamber for a few months, it can destroy everything.

t-von

iTrader: (8)

Hey Tim if it is carbon sticking this is something that I did to my 20b when I first got it a couple years ago to free the carbon sticking of the seals. My 20b had zero compression on all 3 rotors when I got it. Now I have very strong puffs when I crank it over. Look for my post half way down. Also he wouldn't have to remove the engine to do this. All he would need to do is remove the turbos and manifold to have access to the exhaust ports. Use a funnel and pore in some fuel injector cleaner or some acetone to break down the carbon. This stuff will break down carbon unlike ATF. 2 cups worth in each housing will be enough to completely submerge the apex and corner seals in the solution. The key is making sure the apex seals are in the 6 o'clock position. Let it soak for 30min and manually rotate the engine over so the other apex seals are submerged. In between soakings, he could grab a plastic knife and wiggle the apex seals while they are exposed in the exhaust port. This will also help loosen things up. After all 6 sides have been done, a small tube and air compressor can be used to blow the solution out. Install the tube in the housing and blow air across the top of it. This will lower the air pressure over the tube and the solution will come flying out. Also make sure he sprays water in the area that the solution is spray too. You don't want to start a fire during start-up.

https://www.rx7club.com/showthread.p...ghlight=secret


I know this sounds weird but it works and it's a cheap easy fix. I've done it to my Fd when the engine was out while changing the clutch. I also scrubbed my rotor faces with a scotch pad to remove the carbon from them. I have excellent compression with my original 96k engine. Hope this helps.

RCCAZ 1

iTrader: (10)

Wow t-von. Thanks. I'll make sure he get's this info!!

t-von

iTrader: (8)

By the way, anyone can use this method to bring back to life a low compression engine. This will save you a rebuild if it's just carbon sticking from any engine thats sat up so long (especially Jspec engines).

georgekobe8

******* 18 thumbs up for this thread!!!!!! Saved me from selling my car

samad

iTrader: (1)

another temporary fix for fowled plugs we use down here is to heat them up with a blow torch or just put them in front of a gas heater for a while. when ther glowing redish...just let them cool down for a bit and fit them back in. This works pretty well when we have to start flooded engines. Although you should get a new pair if its not a problem!