fast86rx-7

ok to start of its an 88 gtu i think i dont know if there was a base model

ok now for the problems it doesnt want to idle and when it does it misses really bad after it gets to about 4k it cleans up alot
i cleaned the plugs and replaced the wires but it did nothing for it i have not been able to do a compresion check
going on things i was told is that the engine was rebuilt 20k or so ago

what could be my problems?
i have some money but not alot

thanks for the help in advance

rx7b13

check your timing, usually that can clean alot of it up, i know it did on my car.

Aaron Cake

iTrader: (1)

Vacuum leaks, TPS adjustment.

fast86rx-7

does it sound like its internal engine at all im just wondering for worst case

Aaron Cake

iTrader: (1)

I doubt it. Check what I mentioned first.

MARTIN

thats one of the reason I tell people to stay away from cheap rx7's.

fast86rx-7

ok where is the connecter for diagnostics so i can put the jumper in to get into diagnostic mode?

bigdaddyp

ok, how do you check timing on these cars? I want to check mine.

Aaron Cake

iTrader: (1)

Factory Service Manual is available for download in the FAQ.

jhammons01

Leading Coil is bad. hence the 4k change.

fast86rx-7

so you think it might be the coil i checked both and they seem to be ok

when useing a timing light is it normal for it to stop flashing when you give it alittle throttle?

Aaron Cake

iTrader: (1)

Timing lights don't necessarily behave with our ignition system. The only reliable way to check for spark is with a spark tester. Pull one of the leading wires, connect to spark tester, start car. It will run like crap on one rotor but at least you will be able to see if the leading is firing. If one leading plug fires, the other will as well.

fast86rx-7

all plugs are fireing i pulled wire but held close enough so it would bridge the gap and it did it to all leading and trailing at idle

Sideways7

iTrader: (7)

Maybe the primaries are really clogged.

fast86rx-7

i called mazdatrix and toalked to joe and he said that it does sound like injectors and not the coil
but hopefully i will beable to do a compression test on it tomarrow and i will see about adding fuel to see if it cleans up and goes back to normal to see if it is the injectors

RotaryX

Did you ever check the TPS?

Mura

Wow, I never knew that. So just by pulling off one plug on the leading coil, will automatically make the front rotor not run.

JoshRX7

iTrader: (5)

If your car doesn't want to idle... I'd check really good for vacuum leaks.

fast86rx-7

if a compression test turns out good im going to take the uim off and replace all vacuum lines and get the injectors cleaned

Aaron Cake

iTrader: (1)

Yep. If you disconnect one side of the leading coil the other side will stop firing. Each spark plug connects to each end of the secondary coil...

Mura

What about the back rotor? If you were to take off the trailing plug, would the back rotor not work as well, or what?

Aaron Cake

iTrader: (1)

All the trailing coils are separate so they fire independently. All this is covered in the Factory Service Manual in the wiring diagrams.

fast86rx-7

YAYAYAYAYAYA!!!!!!

well the engine is good did a compression test and the rotors on all 3 sides is about 100psi on both rotors

things i tried to see if i could smooth out the engine was add fuel to see if it was the injectors but it only made the engine run worse
i tested the tps and found out it had some flat spots when doing the ohms test so i replaced with a good one and set it at 1k ohms at idle
it has new wires
and a new fuel pump


so now that we know the engine is good what could be my problems
i do have a severe hesitation all the way to 3700rpms and alittle above that

could it be my grounds?
could it be my ecu cold solder joints?
bad vacuum leak?

could be anything else?

plz help me learn

spot_skater

Check all your grounds. Check for any intake restrictions or any unmeasured air. Vacuum leaks are common, too. Might want to check all resistance values pertaining to your AFM, just to make sure that it's in good condition. Don't forget to flush and replace all fluids!

Good luck, hope the forum helps you out!!

James

fast86rx-7

i hope so i cant wait for this car to fly