QuestionHave a 1995 Canadian version of the Hyundai Accent GT with an intermittent
starting problem. On most mornings it will start fine, be able to drive 10
minutes to work and park. After the work day is over it becomes a crap
shoot if it will start again to go home. Sometimes it does sometimes it
does not. Lately more not, hence the question. It turns over like normal but
just won't fire, not even attempt when it gets into this condition. It now
takes sometimes a day or two before it will start again. Once started
though it runs fine and there does not seem to be any hesitations or other
issues whether driving in urban areas or on the highway. As it does not
set any trouble codes we have done some checks such as making sure the
fuel pump is operational ...it is, replacing the fuel filter, and checking
to see if there is spark at the plugs, there are. However when we checked
the injectors using one of those simple test kits, we found that they did
not seem to get any power at the injectors to fire them. There is 12volts
on the common injector rail so that relay is working which leaves the
negative side that the ECM controls as the reason they are not firing. Is
there some other circuits that might inhibit the injectors?. It was my
understanding that the ECM should still start the engine albeit in a basic
mode even though there may be a bad sensor somewhere. One more bit of
info... last night after it was setting over the weekend because it was in
one of those no start modes, I went to try start it, low and behold it
fired up but I did notice that when it started to fire it sounded like the
starter was being dragged down the first few turns before it finally
started, almost like injectors being out of sync. Any advise or direction
would be greatly appreciated.
AnswerIf your engine wasn't cranking at normal speed, it's a good idea to check the battery voltage while cranking. If it falls below 9V, then it's possible there's insufficient voltage for the ECM to operate.
Having spark but not injector pulse is a rather odd occurrence. The ECM needs similar information to provide both spark and injector pulse, namely the crank sensor signal. What is this test kit you've referred to for checking the injectors? Normally, they're checked with a noid lamp. A noid lamp has approximately the same resistance as an injector, so it won't damage the computer if plugged into the injector connector.
Something I might also suspect, especially considering you have spark, is the coolant temperature sensor. I'm figuring when you come out of work that it's rather warm. If the coolant temperature sensor is reporting an erroneously low temperature, the ECM may flood your engine.
I'm also going to toss out the crank sensor as a possible cause because it will cause a crank/no start issue. In this case, you should have no spark and no injector pulse. Also, the crank sensor will typically set a trouble code in the ECM.
