sinisterddg

Hey all new to the forum. here is my deal, i got a 88 rx7 gxl, i just swaped a motor over from another wrecked car.. its got good compression, i got spark and i got fuel... but the car runs like *** when it does run but most of the time it will run for about 45 seconds and die and backfire.. i have NO vaccum leaks, i removed my emissions and made block off plates.. i have NO leaks there either. everything is capped, i dont know the timing deal the book says a yellow mark but i have no yellow mark is it just the first nich? is it not a nich at all? in the book i have it doesnt look like a nich, other issue.. my water temp guage doesnt work because i have no voltage through the green plug.. ideas?? my plugs are not fouled everything is new, plugs wires gaskets coils, the injectors are cool i think, i have good fuel pressure, whats the deal? anyone have any ideas? im about to take a hammer to the damn thing and beat it to a pulp.. any help would be appreciated.. if some guru could call me i would appreciate it anytime 24/7 541 517 7660 name is matt please help guys.

WAYNE88N/A

I know you said you don't have any, but double-check for vac leaks around the block-off plates...

How sure are you that the primary injectors are good?

You probably DO have a yellow mark, it's just covered by years of gunk. Try to clean the indents up a bit with a solvent...

In any case, it's the right hand of the two indents, staring down while standing in front of the car...

For now, you could also try to tweak the CAS within it's range to see if the idle smoothes a bit, then time her right later when she's running good...

The green plug on the back of the water pump housing? That's for your water thermo sensor, and there won't be any voltage there. As it is, the input to the ECU is tiny, on the order of .5v

sinisterddg

but how come my guage doesnt work anymore? i figured it was that mark but when i align the marks on the CAS it still runs like butt... i was told that if the guage isnt working the sensor isnt working what do you think? lol anyone got any other ideas?

WAYNE88N/A

The gauge uses the small sensor sticking out of the rear side housing, near the oil pressure sender, just forward of it, IIRC...Make sure the connector is on there...

Did you align the CAS by-the-book when you installed it? If so, tweak on it a bit to see if the rough running smoothes out...

trochoid

iTrader: (6)

The temp gauge sensor is under the oil filter, next to the 'mushroom', which is the oil pressure sender.

sinisterddg

ok got the temp sensor back online.. got the timing as to where you guys said.. now its starting and dying instantly. is there a ground on the harness other then the one by the back side of the intake manifold to the iron? what is the plug on the same part of the harness by the TPS plug? its green with a black stripe single wire plug any ideas? i wanna go drift tonight guys help me get this thing going please!!!!

sinisterddg

also there is a plug 3 prong plug like this on the back side of the manifold driverside unplugged i dont know what it is white plug | | shaped like that any ideas?
-

WAYNE88N/A

Jumper the two-pin check connector near the air box. This will allow the fuel pump to constantly run with the key on, to troubleshoot the dieing problem. If she continues to start then die, it's probably not a fuel supply problem...

If she starts and runs now after the jumper is installed, you may have an AFM problem.

There are two other grounds you should be concerned with, but if you're getting her to start, grounds aren't your prob...That rear rotor housing ground is the ECU's ground, BTW...

I think the black/green wire is for the e-fan option. Not sure, though...

The last plug you mentioned, I dunno...Air bypass solenoid, maybe?

Just look around for a mate

rs_1101

45 seconds.. really? not like 2 or 3 seconds?
thats strange, but i dont think its vacuum if it runs for that long. have you tried raising idle? if its vacuum, then the car should idle somewhat. what happens if you hit the gas?
theres probably not going to be any easy way to diagnose this.
what i would do is tear the whole thing down to bare longblock, and re-install the whole deal.. at least electrically. that way you can get in there and verify all the plates and crap are connected properly. it sounds painful i know, but itll probably save you time compared to troubleshooting.

also keep in mind. it sounds like start up sequence is going properly, its when the car drops down from the 3k start up that it dies? a clue?

sinisterddg

what is the black wire off the leading coil? is that a coil ground???

sinisterddg

how do i do the jumper trick? what parts do i jumper?

sinisterddg

rs 1101 ive done that.. twice now... the thing is why do i have no power when i can get it ro run.. its just a dog. and i DO have compression.. 2 is very strong but 1 is slightly weaking but still good..

WAYNE88N/A

The black wire at the leading coil is probably the tach signal wire. Don't ground it...

Find the yellow 2-pin plug near the air box, right strut tower area. May have to dig for it to find it. Make a small piece of wire to jumper the two terminals together on the plug. Two small 1/4" spade terminals at either end of the jumper would be ideal, but a piece of stripped wire will work also...

It also sounds now like you need to perform a compression test and post the numbers. Got a compression tester?

rs_1101

when it does run is it like run on one rotor or runs weak?
because that sounds like timing issue. you also gotta consider, maybe the harness was damaged during the installation? that could cause problems. harness diagnosing is a bitch. is the CAS good?
also id double check that emissions removal you did. i think other forum members have had problems with that before.

sinisterddg

ill try that.. the compression should be ok i know enuff about it to figure that out.. ive used 2 different CAS im gonna go through the harness soon tho if i dont figure this out. i got a spare one so ill try it.

sinisterddg

ok i did the AFM jumper thing.. it ran better but it still just dies after like 45 seconds and pops... whats the deal!!! ack

WAYNE88N/A

OK, your fuel supply is probably good, then...

Now this 45 second thing, does she start, rev high (at least 1500 rpms) for a while, then drop down to about 750 and die?

Pops, you mean backfiring? May be a timing issue, then...You haven't found a "sweet spot" for the CAS adjustment yet?

sinisterddg

i dont know just yet whats going on. yes thats exactly what its doing wayne it just doest want to run anymore. i dont get this at all!