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-   -   Purchase '85 (https://www.rx7club.com/1st-generation-specific-1979-1985-18/purchase-85-a-231942/)

crmitche 10-13-03 11:08 AM

Purchase '85
 
I found an '85 in my area for <$1K. Considering picking it up for my son's first car. Body is in reasonable shape. Only problem is the engine has not bee turned over in a couple of years. I'm not too familiar with rotaries, other than the see through model I put together in Jr. high, and wonder what kind of expense I might be looking at to rebuild. I'll do the majority of the work myself and have about 2.5 years before he can legally drive.

Thanks
Craig

Mr BiG G 10-13-03 11:55 AM

if the engine hasn't been turned over in soo long theres a big big possibility that it's carbon locked.....now if the person doesn't know that and u can probably try getting away by telling them the motor needs to be replaced and bring down the price.....bring it home and do the ATF trick....u pretty much pour down certain amounts of ATF down ur carb and turn the motor over....and let it soak properly....try cranking it the next day and it probably should fire up with a lott of heavy black smoke out the tailpipe.....i had a write up on the ATF trick but my computer got formatted so i dont have anything now....do a search and u'll find it....it's called the ATF trick......next step do a full tune up and oil change.....1k seems kinda high for a motor thats carbon lock'd.....try bringing the price down cuz i bought my 83 GSL for 950 canadian with everything perfect except for the ball joints and the tie rod ends.....is the 85 an SE or a lower model....an SE is fuel injected.....the other one is carb'd

Aviator 902S 10-13-03 01:06 PM

Uh, the first thing to do would be to pull the plugs for inspection. The symptoms of problems are the same as you'd find in a piston engine, ie: tan or grey with no moisture = good, wet, oily, or presence of coolant = bad.
Then check the coolant level and under the oil-filler cap. If coolant is down suspect a leak. If there are whitish sludge deposits under the filler cap there's coolant leaking past the inter-housing seals. This may have been caused by an over-heated engine (ie: warped housings), but regardless of the cause the only fix is an engine rebuild.
Next, using a battery that's KNOWN to be fully charged (or use jumper cables from your car's battery), try to start the car. If it cranks over it's not carbon-locked.
The next step is to check compression. You'll need a compression tester that's had the valve unscrewed from the business end so that the gage will not hold a reading. With coil leads disconnected, crank the engine over with the tester screwed into one of the spark plug holes. (NOTE: be sure that other three plugs are installed. Otherwise all compression will be lost through the other plug hole in each rotor housing). As the engine cranks, there should be an even pulse of at least 110- 120psi. If any of the pulses (usually two out of three) barely register anything, the apex seals on that rotor are toast, which = engine rebuild. Test one plug from each housing.
One more thing to check (and for this you'll need a borescope) is for baked-on deposits on the bottom surfaces of the rotor housings, which are visible only through the oil-pan plug hole. Drain the oil, then use the borescope (which has a tiny light on the business end. This end is inserted into the drain hole and angled upward toward the bottom of the housings) to view the housings from the bottom. They should be clean and the same shade of aluminum as the outside of the housings. If there's baked-on brownish-black deposits on them, the engine has been over-heated and the housings warped. If coolant hasn't started leaking into the housings yet, it will soon.
Finally, if the engine does start, look for blue smoke. With a rotary, there will be some whitish or bluish-white smoke on start-up (especially if the car has been sitting for a year), but it will dissipate within a few minutes. If thre's a cloud of blue smoke that doesn't dissipate after five minutes the oil seals on the sides of the rotors are worn, which = rebuild.
BTW, be sure this test is done in warm ambient temps. On cold days, as you know, white exhaust is visible even on good engines.
If all of these tests check out ok the engine is good.


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