Whats up everyone... My car has been down for quite awhile now, cause I kinda gave up figuring out why it won't start after finding out I had no/ little compression. It was running ok before I let it sit for a couple months. I remember changing my oil w/ mobil 1 5w30 a little while before letting it sit, & I had a hard time starting it right after the service. Would my compression be better if I were to use a heavier oil? Oh, and I live in hawaii.... isn't 5w30 too thin for my climate?

Sorry for the story, but does anyone have any tips/info? Thanks.

Allan

 

Well, if you have "no/little compression", the engine won't run regardless of the kind of oil you are using and the oil change would have nothing to do with the inability of the engine to start. Unless something was messed up while changing the oil.

You don't need a "heavier oil" for the climate in Hawaii. I lived there for a couple of years and it never gets hot enough to require any special engine oil. You're fine with 5W-30, but since it never gets 'cold" there either, you could go up on the first number to say a 10W.

How do you know you have bad compression?

 

I hooked up a regular compression tester w/ the schrader valve out & i don't think the needle even bounced. Maybe I did it wrong, but the funny thing is that the car was running fine before I let it sit for a long time...

 

I would suggest that you try putting an ounce or so of oil into each spark plug hole, reinstall the plugs, fully charge the battery and try starting it. Foot off the gas pedal. Crank the engine for no more than 8-10 seconds at a time with pauses in between.

If it still doesn't start after 3-4 tries, you will need to go through a simple troubleshooting procedure like: verify spark at the plugs and fuel delivery to the engine. [If you don't know how to do that I would suggest that you turn the problem over to someone who does.] If both those are good, the car should start. That is, unless there is more to the story.

BTW, how long is "...a long time..."? A few months, years?

 

I would bet you're doing the compression test wrong; It's pretty inconceivable to me that you'd go from a car that runs perfectly to one that has NO compression on any face of either rotor after only sitting for 3 months....

Do you know anyone who has more experience with compression testing rotaries?

 

Yeah, pretty embarassing that I'm a mechanic who doesn't have the time & no experience w/ rotaries lol... but the oil in the plug holes was kinda what I was getting to. Seeing that the car was sitting & the seals are probly dry or something.

As for how long.... The no start problem was after 3 months, & now it's been almost a year since then.

 

You may have stuck seals which could lead to no compression. Put some oil in there and hand crank a bunch of times to lubricate the seals and then try starting.

 

I dont know which to do.... one says hand crank & another says crank for 8-10 seconds. Or either way would work?

BTW thanks guys, all of this advise is very helpful & is kinda lighting a fire under my *** to finally get goin on my fc.

 

www.aaroncake.net

There's a section on his car, then a subsection on dealing with an RX-7 that's been in storage. You might find something helpful there.

Outside of the engine you should find everything to be pretty familiar. Common engine problems (for after you get your current problem fixed) include flooding, sensitivity to overheating and sensitivity to oil starvation. To fix flooding, search the forums. It's pretty easy both to prevent and fix. For the other 2 things, just take good care of the cooling system, oil cooler lines and oil drain plug and don't overheat it or starve it for oil. Simple as that.

The type of oil typically doesn't make a huge difference. Try 10w30 or 20w50. As you can see from this forum's FAQ, your outdoor temps are around the upper end for 10w30 and in the middle for 20w50. So it's a matter of do you want thin, slick, good flowing oil or thicker, more gooey oil that stays on your seals and parts better? Other weights work fine too, but these two have the least viscosity additives (and more of everything else). Viscosity additives just widen the temperature range even further to account for seasonal changes. Who needs that in Hawaii??

 

The 8-10 second cranking is an attempt to start the engine. The rotating rotor will coat the walls of the rotor housings with a thin film of oil during the first few seconds of cranking to increase compression, which is what you need the oil in the plug holes for. If you want to first crank the engine by hand to accomplish this, go for it, but it's not necessary.

If the car sat for a year without running, you may want to drain and replace the fuel. Gasoline tends to change chemically over that period unless you add a stabilizer.

BTW, If you're a mechanic, have you checked for spark and fuel?

 

Yup, that's the first thing I checked for. Didn't take long to narrow it down to no compression, & once I found that out I was like screw this... until now. Like I said, I'm a little unfamiliar w/ rotaries... rotary & piston engines are like night and day to me. Plus I don't know any rotary mechanics here on Maui.

 

Rotary engines need a film of oil between the seals and the wall of the housing in order to "make" compression. Hence the oil-in-the-plug hole routine. Under normal operating conditions, the metering oil pump supplies enough oil when mixed with the fuel to accomplish that. When an engine sits for a long time, the oil/fuel film that was on the walls when last run, can evaporate, dry up or run off causing a loss of compression.

Suggestion: Send a PM to RETed and ask him if he knows of a rotary tech on Maui. He's in Honolulu. Maybe he'll wind surf over to give you a hand.

 

We got Super Ferry now!

I would be willing to help you out, but I got a bet with someone I don't want to lose...long story.

I had my FC sit for over a year with no problems starting.
I have to admit I do premix, so that probably helped a lot.
I wouldn't think a few months would hurt it.

My compression test page:
http://fc3spro.com/TECH/FAQ/compress.html

For now, I would remove one spark plugs per rotor and hit the starter...
Listen for at least 6 even "whooshes"...


-Ted

 

OK thanks guys, Ill give it a try today & see what happens......