comeonstart

i have a 87 rx-7 base model which i think is called the GSL. but any way i having trouble starting the car has been siting for 2 years and i drains gas and flused lines and everything checked spark turned it over eithout plugs. seemed water was in it and it was defintly blowing a visible vapor of old gas out, and it was defintly blowing hard through plug hole so its compression cant be that bad. when i put the plugs in and try to start it, it sorta chaches on but wont quite start. and there is a fog of old gas blowing throuhg the exhaust.

mod are full borla exhaust, and spusepsion stuff as far as i know.

Bach

banzaitoyota

pull the leading plugs , add a teaspoon of ATF to each rotor, install new plugs, will fire and smoke like a bitch if it has any compression

comeonstart

I went out and did it, and while i was taking the plug out i noticed that the disttributro adjustment bolt was out, the distributor was counter-clockwise about a 1/2 out of its limits so i reach down and turn it with my hand to about half way on either side. the car did fire an ran for a couplde seconds before bogging out, it reved to a maximum of 4 grand before dieing. I put more in it and got the same results. then i put my compression tester on it and got about 130 psi. Is that good? and where can i find the timing marks on this puppy so i can correct the timing. I know how to do it, i just dont know where the t and f marks are. thanks for replying

Bach

comeonstart

I went out at it again today, it started a little better but only for a few seconds and bogged out immediatly. I can start it now when i put the distributor in a certain spot but it only goes to 1k and dies on me, very very rough running in its few seconds. I think my biggest problem now is getting the timing right.


Bach

black_sunshine

If it starts and dies, it can be many many different things. Okay, first things to check: Are ALL sensors and devices hooked-up correctly? BACV (on the plenum); this helps contol IDLE SPEED. The AWS solenoid;

Accelerated Warmup Solenoid. This runs from the driver's side of the plenum, to the actual solenoid, to a metal tube across the top of the motor, and into the air-intake tube (goes from air box to throttle body). That is most likely your problem. If this is NOT hooked to the intake BEFORE the throttle-body, the car will start, rev to 3k-4k rpm, and then drop down and idle roughly before stalling. Make certain there are no air leaks of any sort. Also, make sure the little 90degree plastic elbow is properly inserted to the bottom of the intake tube, and be careful not to break it; they're kind of brittle.

Throttle-position sensor (on throttle body), water temp sensor (it's on the back of the water-pump housing, just below the alternator), the AFM (Air Flow Meter; it's bolted to the intake air-box on the bottom). This probably needs to be adjusted. Do a search for "Throttle position sensor Adjustment" or something similar to find out how; this will just usually cause an erratic idle, but usually not stalling. Causes many, many other problems, especially if it's bad (unlikely).



Boost (pressure) sensor on the passenger side suspension pillar (it's also supposed to have a little "restriction" pellet in the hose or it may hesitate (small "bump") from 5k-7k rpm).

If that's all hooked-up and working, then replace the fuel filter and check the fuel pump to make certain it's working correctly.

After thoroughly checking everything and everything is in proper working order, then you probably have a bad AFM, but don't bet on it, they rarely go bad.

Checking compression on a rotary is pretty tricky without a $1,700 USD tool that measures each of the 3 faces of the rotor; they'll each have different values. Best way to check is to take the schrater-valve out of the compresion tester, hook it to the top (Trailing) spark-plug holes, and have someone turn the car over (make sure to pull the EGI fuse or it may try to start). You should see 3 EVEN bumps on the gauge. Typically, a used motor will get anywhere from 90psi to 150psi; your mileage may vary. It's difficult to get a decent reading, but if it goes over the 85psi mark 3 times per rotor housing, then your compression is usable. The more, the merrier.

As for timing, generally, the CAS (crank angle sensor) should be 1/4 of the way clockwise. As long as you don't have it 1/4 of the way CCW, then you'll be alright; heck even at the latter, it'll still start and run fine; just rough and you risk severe damage to you engine; similar to mixing the Leading (bottom) and trailing wires up.

hope this helps a little!

Matt

1adzam

Black Sunshine... how do you adjust the AFM? I havn't seen anything to adjust or did I mis-interpret your post?

black_sunshine

Oh, sorry, lol!

I don't think you can adjust the AFM without totally destroying it (tearing it apart). I just kind of glazed over my post, but I think I was just talking about doing the check on it (measuring resistance). Sorry if I mislead you

comeonstart

the intake was stripped down to the throttle body before so i put it back together, and it hasnt gone past 1k since then yet, it doesnt stall if just acts like i am pouring gas down the intake, i checked fuel pump, pumped a gallon in no time at all, i dont know how to check the injectors. I can tell you that the gas its getting is WAY too much, I am quite knowledgeable about piston engines, and 2-strokes, rotarys are new to me. would it be possible to use the check vavle to try to get better readings? the car has 139,000 miles

Bach

black_sunshine

If your injectors are bad, they'll get stuck open when they pulse and dump fuel in. Get a lantern battery (1.5v) and attach some alligator clips to the injector terminals. Listen for a click; if you've got a click, then leave the wires connected (not for more than 30 minutes at a time) and let them soak in BP blaster or some other rubber-safe solvent. Click them (on the battery; most solvents are flamabe and a spark on the injector terminals might light a fire) periodically to help get junk out of them if there is any. There's 4 injectors total; secondaries on top, primaries are bolted directly to the engine and are kind of hard to get to.

A bad TPS (one that's reading WOT when the throttle is closed) will cause the injectors to spray a lot more fuel than needed; do an ohm check on it and make sure it changes (the ohm reading) smoothly when you slide the piston in and out.

Boost sensor. If it's not working or not hooked-up, it can also cause a rich scenario. Disconnect it and see if there's a difference in the way it runs. If it gets worse/better, then it's probably bad.

Rotary engines operate (on a fuel-system level) the exact same way a piston engine does; they even share the same Bosch Jetronic Fuel Injection method; it may not be made by Bosch, but it's the same basic setup. Just treat it like a piston engine when diagnosing a fuel delivery problem. A four-cycle engine whose valvless-induction and lubrication system mimic a 2 cycle.

Hope this helps!

Matt

comeonstart

well I went at it again today, and i found a for sale sing in it stashed away, it says 87 rx-7 new clutch, new starter, good tranny, needs engine, low compression $800 obo. xxx-xxxx. so I think i know what the problem is, and as far as i reasearched the lost-compression is way to expensive to fix, as the roatry cost to much to rebuild. i am now looking at a bb-shevy or sb-chevy or ford v8 to take its place, they cost a dime a dozen and i cant put too much $ inot this car as i have to do a substancial amount of body work.

bach