tdr1919

I have a miss when accellerating, sometimes pretty severe. I recorded about 15 minutes of driving using Datamaster. Can anyone tell me what relationships I should be paying attention to when trying to decifer this information?

Thanks,
Tom

0Paul Ruggeri

I would check the plugs and wires first. If they're OK, see if the datamaster shows a lean condition.

engle1147

Done any mods lately? Sounds like the air/fuel mix is off for whatever reason.

JackDidley

What year is the car ?

tdr1919

its an 86 manual, and i was determined to find out something, so i went out with my drop light and a can of throttle body cleaner. I recently upgraded with (FIC) Bosch II injectors, new fuel filter. I had this miss before I changed the injectors. So it really comes down to basics, if it sounds & acts like a vacuum leak them most likely its a vacuum leak. I started it up and sprayed the cleaner around the plenum, as I sprayed around the throttle body the RPM's increased.
I pulled off the throttle body and cleaned the mating surfaces I even replaced the gasket. Put it back together, started up, sprayed around the throttle body, only on the drivers side, rpms increased, I found a crack in the vacuum hose ( part of the crankcase ventilation) new hose
all good seems to have cured the miss on accelleration!

-Tom

JackDidley

If you email the datalog to me, I'll take a look at it.
Z666wright@yahoo.com