hello my name is matt and im lookin at buying a 86 rx7, i need some help... the car has 155k miles and the engine bay is very very clean... the car has been very wel ltaken care of and everything looks to be in very good shape...

well the car has been sitting for a year. cause the owner didnt have a licence and doesnt want the car any more...

the car starts up fine.. .every time... BUT it will run for like 3-5 seconds and then compleatly die, even if ur giving it gas... the gas pedal has allmost no effect on it what so ever, in the few seconds it runs it will not rev at all just tried to stay steady at 1.5 rpm.. it will try to bring the revs back down to a grand or so and then just dies... even with the gas pedal to the floor... does any one have any idea to what could be the problem... and withthe gas down it would die even faster,....

we tried to get the car running for like 30-45 min starting it letting it runn and then it dieing at first it was only like a second or two but at the end it was trying to run for longer perioids but would die trying.. you could smell gas int he engine bay but it smelled like old gas.. hense why we tried to get it runing with new gas... the other guy was adjusting a screw on top of the intake manifold trying to adjust the fuel ratio or somehting.. he mostly backed the screw out... we also messed with the screw that controls the idle.. im thinking its somethig fuel related??

does any one have any ideas to what could be wrong??

im fairly new to the raotary car, but i have been working on pistsion engiens for a couple of years...
i have allways liked the rx7 and iw ould really like ot get this car, i have been given a VERY good deal on it.. but i dont want it unless i can depend on driving it and it running well..
thanks in advance for any help....

MATT

 

check the Air Flow Meter (AFM) in the air intake- take the plug off of the AFM, get a meter set to ohms, and read out the first two sockets on the AFM itself- you should read open (infinity), now push on the flapper door in the AFM (might need to remove the air filter for this), and read the same two contacts- you should get a reading near 0 ohms (internal switch contacts made)...if not, that's your problem...you could also check this out by putting a jumper wire between the two terminals on the yellow check connector that should be in the same area (this effectively bypasses that AFM switch)...if the car starts and runs fine after this jumper is installed, the AFM switch is your problem...if not, I've typed all this for nothing

 

can u get the car to run with the afm byepassed like that?? will it run like the 15 miles from the current owners to my house fine?? and how much is a new mass air flow sensor... i mean afm?

 

you can run it- just don't wreck it, the fuel pump won't shut off in the event of a collision with that plug jumpered...I think last time I looked at a new one, it was like $900 or so, so if it's bad, look for a known good used one...

 

900?!?!?! holly ****?!?! thats more then im paying for the damn car!!!

 

ha ha, welcome to the rotary!!! so, if you gotta go get the car, just take a 3-4" jumper wire with ya and jumper the plug...if it works, great, if it don't, get back with us...I should insert my DISCLAIMER now that if you do jumper the plug and wreck the car & get burned up in the process, it's NOT MY FAULT!!!

 

lol yeah it will compleatly ur fault.. i allready wrote a nite to my parrents to why lol... j/k

well ill go tommorow and try tro get the car running... hopefully this works...

 

USED AFM= 30 BUCKS. hes new dont give him numbers like that. ****. who would buy a new afm anyway?

pat

 

where can i get a uesd one at and forgive me for any newbish q's

 

one of the forum members probably has a used one for sale, sorry, didn't mean to scare ya with the $900 figure!!!

 

lol its kwel.. i knew maf sensors were expensive

 

BTW, you need to un-tweak all the tweaking you guys did on the idle adjustment, etc.., you might have made it WORSE...

 

ok well the cars at my house... i tried that byepass but it still didnt work... it did act like it was getting better but it wasnt doing much...

 

help me please... i dont know whats up with this thing... it sounds like its a stupid sensor or somehting... it starts fine like every time reves up to like umm 2.5-3 grand and just dies... i dont know what to do.. i have replaced the fuel filter... the spark plugs twice.. checked the fuel pump... it seams like its soehting sensor wise cause it starts fine... every time i turn the key allmost... i ahve tried that deflood whereyou pull the egi comp fuse and turning the engine over with the gas to the floor...


it sat for a year with out a battary.. is there any sensor or somehting i need to reset to make it run correctly??

my cusin thinks its some kinda of fuel cut off inertial switch.. like to turn the fuel off if the car flips or is in a big wreck...

i ahve gotten it to run a few times for a few minutes but it still dies after about 5 min...

please help me!!

my parrents are going to make me sell the car if i cant get it running reliabliy

 

any one please? help me?!

 

if it's starting, it's probably NOT flooded...are you SURE it's not that flapper door switch in the AFM? 'Cause those are the exact symptoms when they go out...you have a jumper wire on the two-pin plug on the right side just behind the filter box?

 

maybe the TPS I dunno for sure though. Umm I have the same problem with a series 5 but it runs smooth @5000 rpm. also the exhaust might be plugged? primary fuel injectors maybe.

 

Sounds like the AFM is not securely attached or the plug is disconnected.

 

check for vac leaks!!!!

 

Geeze.. why make this so complicated and expensive. The car sat for a year. Change the fuel filter and replace the in tank sock. Its dying because the old gas crud has varnished up the filter and the screen.

 

allready changed most of the fuel system including filter and strainer

 

Maybe the pump went bad.My car did something simaler and it was the pump itself.When the fuel sock gets varnished little fuel can get into the pump,causing the pump to burn itself out(fuel cools and lubes pump).Also test to see if you get 12 volts at the fuel pump connector while it's running.And if you can test the fuel pressure.Check your sparkplugs they may be worn.Also read the fsm on how to test the coils too.

Good luck

 

it is almost certainly the afm or a big vacuum leak. when you start the car, it revs for a second, then it gets the signal from the afm. if the afm is broken, or if there is a leak somewhere, this signal causes the ecu to adjust the mixture incorrectly, and the car dies. if it was fuel, coil, etc it wouldnt rev and stall, it would just run shitty or not at all. if you have tested the afm and are satisfied that it is not broken, find the vacuum leak, cause there is one somewhere. a big one too.

pat

 

well lol this is te second time im typing this message cause i hit reset forum instead of submit... damnit... lol... well i got the car runing last night.. i found a vac leak conecting to the check vavle??? what is that used for.. i coudnt find one at az or pepgirls, so i left it out of the system.. i couldnt thing of it hurting anyhting and it started after i hooked up the vac lines so im guessing its not...
after starting it i spent like 30 min adjusting and tweking the idle... she running fine starts up everytime...
but i have noticed one thing though there is a short in the wirse going to the afm... if i take the car above a certin rpm or jar it hard it just dies imdeadityly.... i think its some where around 4.5k rpm so its still driveable.. but if it cuts it i have to disconect the sensor start the car, let it die and then restart the car with the sensor pluged back in... go figure...

but after doing some dirving the car has a vibration... well a major vibration... it feels like a warped driveshaft or a bad bearing somewhere in the drive train... it only does it above 25mph... and at 60 its giving a really nice and numbing back rubb... i think if i keep the speeds down it should be ok to drive back and forth to work though (12miles).. well hopefully... should i get a stock driveshaft or aftermarket.. i plan to keep the car for a while and possiably start autoX...

well again thanks for every ones help...
Matt

 

any one??