Still have not heard if he has 12 volts to the injectors.
Without that, he doesn't stand a chance.
He can check that with a standard 12 volt test light to ground.
The other test light check is to put the test light from batt pos to
the "ground" side of the injectors and crank the engine. If the light
flashes the ECU is triggering the injectors. If he has no 12 volts and
has a trigger, it will be a connection, fuse, or relay. If he has no
12 volts AND no trigger it will be one of those common to both the
injector circuit and the PCM.
If he has no 12 volts and has a trigger it will be one specific to the
injector power only.
Posted via a free Usenet account from http://www.teranews.com
No, I am still working on it.
When performing QA1, QA2 and QA3, and all the other pinpoint tests,
can I simply disconnect my PCM and test on the connector or do I need
a breakout box in order for the tests to be run properly?
Do a compression test to a few cylinders. I know of someone who had a 1991
GMC pickup that had the same problem. Turned out his timing chain snapped
& the camshaft wasn't rotating. If your distributor is driven by the cam then
will not be the problem but it doesn't hurt to check compression.
I've seen the module go bad
on some of them fords and still let the spark plug fire
but would not let the computer know when to fire
The only way is do a noid test on the injector harness
some part stores have free module test.
need to check the fuel pressure also.
The best I can figure, the injectors are connected directly to the
Does that mean the PCM is bad?
Since the non-code reader code reading thing did not
work (see above), I bought a code reader and I am
about to try it. Since the non-code reader code reading
thing did not work, I am not confident the code reader
I am not going to go into a lot here to cause more
confusion. You indicated you have spark at the plugs. We
have no idea if that spark is timed close enough for the
engine to run but, since you said it would run with starting
fluid sprayed into the throttle body when cranking, you
should for now assume the ignition system is functional.
Keep in mind that the EEC-IV ignition system is not
entirely dependant on the vehicle even having a functional
PCM. If you do not know how to chack basic timing while
cranking the engine with a timing light, you will will just
have to trust me that it can be done with a timing light.
Use a piece of chalk to mark the damper for good visibility
and you will have to look very closely while checking.
Also, your spark needs to be a bright blue capable of
bridging a 1/2" (13mm) gap to run that engine or most any
other EEC-IV system. Starting fluid can be ignited much
more easily than the lean mixture of gasoline the car is
designed to start and run on. You timing should be no more
than 15 deg from specifications. If it is, you must find
out why. If the distributor is still tight and has not
moved, you may have a failed timing chain. Most of the
failed timing chains I have ever replaced were in engineds
that were running "well" when stopped and would not restart.
This can be verified by suddenly drastic sbhange in ignition
timing and using a dial indicator and degree wheel to check
valve timing. A compression test showing all cylinders
uniformly low will also be an indication.
You have said there is no activation of the noid light (s)
when installed on the injectors. That does tell us they are
not being pulsed and will not provide fuel. The 12v to the
injectors is regulated and supplied by the PCM. The PCM
controls the injectors by switching the ground. If this is
not happening, it is an indication the PCM may be bad - they
do not often fail.
You indicate the fault light lit dimly if at all instead of
bright very defined blinks. If you followed the
instructions to the letter and could not get a readout, this
is an indication the PCM is not working properly. Even when
expensive diagnostic equipment cannot get a response, this
method usually works if the PCM is functional at any level.
Before the PCM is condemned, you need to ascertain the power
supply to the PCM. Make sure you check the EEV-IV relay.
Lastly, have you checked the Inertia kill switch? If not,
find it and push the reset firmly a couple of times. The
one in my CV tripped a few months back. We came home and
everyone got out. Next morning, it cranked like always but,
would not start. Engine had ignition and no fuel. Without
thinking it thru, I called fro a new fuel pump even though
it had pressure. Before leaving, I remembered the inertia
switch and pushed the reset a couple of times. It fired
right up and hasn't missed a beat since.
As it turns out, the inertia switch does not kill the
ignition system at all just the fuel side. It won't cost
you anything to double check it. Mine had to be pushed very
firmly to reset.
I plan to pursue each of your recommendations.
FYI: Following is a list of other things folks in this NG suggested I
pursue that I have not yet pursued, but plan to in the following
order. (Any comments or advice from you or anyone else would be
2. PCM Ground.
3. ECM Ground.
4. Fuses (Although I wish I knew which ones specifically they
5. Relays (Although I wish I knew which ones specifically they meant;
e.g. Fuel Pump Relay and/or WOT Cut-off Relay and/or Others.)
6. Fusible Links (Although I wish I knew which ones specifically they
meant; e.g., D behind the PCM and/or Others.)
8. PCM Swap
Forget #1. Concentrate on #2 and #3 (same thing). and #4.
The fuse in #4 will be labelled ECU or EFI and can be identified in
your owner's manual.
If you have a schematic available you will be able to determine which
wires should have power and from which fuse. You will have one
unswitched power that maintains memory and one switched power that
feeds the logic of the computer. The feed to the injectors themselves
has been verified, which eliminates the EFI relay (at least on any car
I have worked on) The fusible links have also been eliminated, along
with the coil.
A PCM swap (assuming you can get the right one) would prove you DON'T
have a power or ground problem if it woeks, but if it doesn't work you
are out the cost of the ECU/PCM and still need to do the ground and
My gut feeling from the fery start was a bad ECU ground. If I had the
manuals available I'd point you to the proper connection but my
brother, who has the Mitchell On Demand program on his shop computer
is out of town so I can't get to it.
If he's not too busy and stressed tomorrow I MIGHT be able to get onto
the system and check it out. What year and VIN code?
Posted via a free Usenet account from http://www.teranews.com
Joe - read this whole thread myself. Tend to agree with the folks that
say CHECK THAT GROUND....there's a reason that car ran fine one day
and not the next.
You're getting fuel, spark and timing has not changed....check the
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