humboldtgirl707

so i'm driving and my rpm needle drops to 0 and my check engine light comes on, but i turn my car off and when i turn it back on the needle works again and then goes to 0 again, it also pulls like i'm running out of gas, any suggestions on what it maybe? i just put a new battery in, and someone told me it sounds like i need a new fuel filter, i know you cant diagnose my car problems by just this but any suggestions may help.

thanks

Zyrano

What year car is it, carb? fuel injected? that would help... Fuel filter is definitly a good thing to check, but it shouldn't mess with the tach. I'd probably start looking at ignition, but need somemore info

socalrotor

iTrader: (1)

Your coils control the tach output. I cant remember which one, but look there first. I think it is the trailing, so if the tach isnt working, my bet is your conectiions loose or a coil is going bad. It has NOTHING TO DUE WITH FUEL!!!!!!

teddyrx2

iTrader: (33)

Just check for a lose wire that is all it is. It has nothing to do with filter and stuff

socalrotor

iTrader: (1)

hey teddy, custom doesnt have a E on the end of it....check your sig!

humboldtgirl707

right on, ill check the connection to my battery thanks guys
its a 90 rx7 vert

socalrotor

iTrader: (1)

Check the coil connections and make sure your getting spark output from ALL sparkplugs. There is a coil pack right by the Battery, so look there first IMO.

teddyrx2

iTrader: (33)

Simple mistake was typing to fast

socalrotor

iTrader: (1)

well your welcome bunghole, BTW have you done any wet NOS kits on a s4 fc?

trainwreck517

iTrader: (1)

Since its a S5 FC, have you checked the check engine code? I'am about 99% sure its going to be a bad trailing coil.

humboldtgirl707

what is a S5 FC? I'm not hip on all the car codes and lingo yet

prjct87rx7

iTrader: (7)

its a 89-91 rx7 s4's are 86-88 by the way mine was doing around the same thing your is,and it turned out my c.a.s was picking up engine noise=bad cas

but im not saying thats whats wrong with yours.

pshaw118

pm Do Luck. He should be able to get you squared away. k. thx.

Shizat

iTrader: (22)

Hey bro, had the same thing happen on my 85, 1 of your coils is gone bad, not sure which one but it is definately the coil, it also controls thr fuel pump that's why it feels like it ran out of gas, u r better off changing both coils once u determine which one it is, hope this helps................

Spirit Rx-7

iTrader: (15)

you guys sure its the coil? i have been running on a non workin trailing coil, and my tach seemed to idle fine. the only thing is it feels slower on the low end.