PaperNinjaRotor

So i have recently bought a 1988 GXL, the cars motor was rebuilt about 2000 miles ago by RX7world in Rock Hill, SC. The motor has a baby bridgeport, polished and balanced rotors, racing bearings, and some other things. The cars air pump has been removed, So has the oil pump thingy and so therefore i have to premix, i use Ibemitsu rotary premix because its supposed to be the best. For the first couple of days the car drove like a champ no problems whatsoever. I must also add that the guy who had it before me has the most ghetto exhaust system ever, it is cut from the pre-cat all the way down to where the Y-Pipe is so there are no cats on it at all, stock mufflers are still in place. Today while driving i was downshifting to turn, BTW i live in SC so i dont have to pass an emissions test, the car cut off, but i popped the clutch and it came right back on and i kept on driving, now its doing this whenever the RPMs get low, and sometimes it wont even idle. After the car sits for awhile and i crank it up it idles perfect not fluctuating or anything but once i go to drive it i have to continuously give it gas to keep the car on, sometimes i can get it to idle though. Then while the car was idling, i was sitting parked and went to turn the steering wheel out of boredom and noticed that it caused the car to bog down, the same night as i tried to roll up my window and turn my gauge lights on, the car wanted to bog down. In higher rpm and while driving the car drives like its perfectly fine, only in the low rpm range 1100 and down, does it start to wanna go down and turn off. Any help would be greatly appreciated for i really like this car. My first one was destroyed by a giant truck... once again Thank you very much

p.s. its a non turbo model

AGreen

iTrader: (11)

First off, check to see if the BAC has been removed. Warm the engine up, and jumper the initial set coupler. Check the idle speed, and adjust it to around 750 with the screw on top of the throttle body. Check the TPS with a voltmeter on the green/red and black wires at the connector. See if it's reading 1.000 volts DC. If not, adjust the TPS screw until it reaches that voltage, and you can blip the throttle and it returns to 1.000 volts. It takes a while. Now check the timing (inductive lead attached to L1 spark plug wire), and adjust it by loosening the nut on the CAS and turning it until you see the 15 deg ATDC mark line up with the pointer by the crank pulley. You'll need to borrow a timing light from a parts store.

Remove the initial set coupler jumper and see how the car drives. If any of this confuses you, you can download or view the entire FSM from RotaryHeads.com - 2nd Gen RX-7 PDF Technical Manuals FC3S . You'll want to look under the Fuel/Emissions section (non-turbo). This should solve all your woes.

RotaryEvolution

iTrader: (30)

unfortunately this sounds like one of hundreds of electrical symtpoms within the engine controls, check all connections on the engine and replace any questionable connectors for major items like injectors, AFM, pressure sensor, ECT, TPS, CAS, etc.

check fuel pressure when the car runs normally and when it runs like crap.

check the compression of the engine.

check battery voltage cold and warm.

check the timing.

check the TPS.

check for vacuum leaks while the car is running like crap.

if that all fails then either set it on fire or buy a standalone and don't look back.

PaperNinjaRotor

Thanks for the advice, i will start on that today, but more is happening now, as of right now the only way i have been able to start the car is by a push start and it is getting old quick, whenever i turn the ignition all of the idiot lights come on but the starter does not engage, the car just sits there, then after we get the car started by pushing it, it will begin to idle, and will idle for a few minutes just fine and then turn off.

KronicKrazy

I was trying to adjust the tps to 1.000 volts but the screw wouldnt keep turning and now its stuck at 1.88?

satch

iTrader: (1)

TPS is supposed to be set w/the engine as hot as it can get and not somewhere close. Is this how you are doing it?

KronicKrazy

yes, i drove around red lining it around town before i started. I was also told that it might be my maf sensor out of whack since i turned the adjusting screw all the way and it didnt help much.

RotaryEvolution

iTrader: (30)

if the AFM air bypass screw didn't affect how the engine runs then it is either getting way too much fuel or not enough of it. it sounds as if it has a number of vacuum leaks which will cause the engine to want to stall very easily.

a bridge requires more fuel than the standard configuration anyways, you should really look into a piggyback fuel management device like an SAFC so you can richen it up for the bridge.

PaperNinjaRotor

Hello! My problem has been fixed! while going through the checklists provided by you guys and the FSM, i found some god awful grounds and wires that were torn up, replaced all of those, and voila my car soared to life and is running like a champ again, also my starting problem was the solenoid was burnt out, it was receiving power but not engaging the starter, but never the less, my baby is running strong again, thanks!

KronicKrazy

do you put the positive lead on the green/red wire, and ground on the black? and do you start your car when you do this test? or do you just turn it on without starting it? do you not do either of those and leave it off?

do i put the setting on 20 dcv or use dc 10a?

i put the red lead in the green/red wire and the black one on the black wire and i got no reading at all. what am i doing wrong?

KronicKrazy

please disregard that that^^^


here it says to check resistance http://fc3spro.com/TECH/HOWTO/TPS/tps.html. where are you getting dc from? i tried checking dc but i got no reading at all. so i tested resistance and my adjustment screw wont let me go down any further than 2.00

why wont my adjustment screw not let me take it down any further? is my tps completely messed up? do i have to adjust something else?