ydeardorff

I found a 1986 RX-7 in a guys back yard. It had been left there after the auto tranny blew. So were talking about 1 year and a half. I changed the gas out as it was varnished up badly. The rear rotor after one night of marvel mystery oil is pumping 115 PSI. The front rotor is pumring a wimpy 25. I had it running for second on starter fluid, then nothing. I am currently soaking the front rotor again. with the key on I get no fuel pressure. Is this because of a blockage, or does the motor have to crank to get the pressure up? Do I need to take the fuel system apart? Do the injectors need to be cleaned?if yes then how do you clean them. At 600 bucks a pair I'd preferr to learn how to clean them. The motor cranks cleanly and fast like it should. Still no decent pressure in the front rotor after one day of MMO. I am thinking of switching over to ATF if the marvel doesn't cut it by tomarrow. I am messing with the idea of getting deisel and trying that. I was told to try easy off oven cleaner, but that seems a bit harsh of engine parts. I pulled the exhaust manifold off and looked at the rotors and apex seals, they look fine and not brken at all. Just nice and shiny. I have been told my engine suffers from carbon lock. How long does this take to fix?

peejay

Use ATF, not MMO. ATF has detergents.

Let it sit for a week or more. Maybe a few months, adding fresh ATF every so often. It's real mild detergents and it doesn't act quickly. If you want fast action, disassemble the engine and clean it by hand / with supremely nasty chemicals that would eat the coolant seals and oil control O-rings for breakfast.

Ixnay on the oven cleaner-ay. Oven cleaner dissolves aluminum. What are the rotor housings made of? Aluminum. Yes the inner surface is chrome plated steel, but you *can* get to aluminum from the combustion chamber area, like in the spark plug holes and the exhaust ports.

If your engine was carbon locked, it wouldn't be turning at all. Most likely the front seals are stuck, if they don't look all gouged up and narsty. Diassemble the engine and clean it manually, or dump in ATF and let it sit for a few weeks.

ydeardorff

Thanks on the xnay thing, I have been a mechanic for close to 20 years now, and lets just say I have never used oven cleaner on ANY rebuild. The apex seals are in seemingly good shape minus the fact they are suck in the compressed position. I have taken the exhaust manifold off, so I can crank the motor over when both rotors are working good, to sling as much of the MMO out of the engine as possible and not downthe exhaust. It is a minor thing to remove the exhaust and save 5 or ten minutes causing the fire deptment to show up at my door step. a little smoke for a minute or two is minor and can be done at night, to evade the attention of nosey neighbors. But my car is still soaking, I let you know how long it takes for a motor like mine that was running, and was stored in a backyard in desert conditions, as I live in Nevada.

peejay

For what it's worth - I soaked a carbon crusted rotor in a pot of ATF (note: do not come over my place for spaghetti unless you use Dexron as pasta sauce ) and while it did dissolve the carbon it did so VERY slowly. Didn't do a damned thing in the first 24 hours.

tecknix

Is there any referrence to ATF.. I've never seen it for sale :-\ Sorry for the dumb question..

eljefe62

ATF=Automatic Trans. Fluid

Dom_C

you can jump the feul pump. i had the same problem. My car ran out of gas so the system was dry. i jumped the pump and was fine hold on while i find the link. ok here it is
https://www.rx7club.com/showthread.p...hreadid=283582
this has a diagram and everything. it worked for me. the fuel pump isn't on uless the car is cranking and or if it is running. with this little trick the pump is on while the ignition is in the on position. as for the atf. do a search on aaron cake. He has a good write up on the ATF tratment and how it might not be very good fo ryour seals and junk. Hope i could help.
Dom

duboisr

With the manifold off bring a seal in to view ,and spray some solvant on the seal .Take a piece of hard wood or plastic and push on the seal lightly to free it in the groove . Push both ends lightly . If it frees go to the next one .I friend of my mechanic would soak stuck seals in brake fluid .That always worked for him with engines that came from the junk yard .

Dom_C

oh man, brake fluid is bad stuff. i'm ure that it will eat rubber seals for lunch. watch out while trying bf. may work but i wouldn't risk it i don't think. maybe if it was in there for a very very short time. i dunno though. sounds risky.
DOM

Dcrasta

All this fear about brake fluid eating seals (And ATF eating seals..) but there are rubber seals all over the car, in the brake system (in the master cylinder), in the Trans, (if u have a automatic) in the power steering system (the damn hoses are rubber!). I think the brake fluid job on the apex seals sounds like a great idea, or u can try SEAFOAM cleaner that stuff works great. If u can get the car running try ingesting some seafoam (use a vacuum line like the brake booster line to ingest the seafoam into the engine while its running (hold the revs at 3k or so)) its gonna make alot of smoke but will clean the carbon out. I got my rear rotor back to 120 psi that way (Took a few trys).

igottafc

iTrader: (6)

ok, someone explain the ATF trick cuz im not following how it works