Mechanics

3.2 V6 WONT START, HAS SPARK, FUEL, AND TIMING IS GOOD. NO INJECTOR PULSE

1994 Isuzu Rodeo • 132,000 miles

I have a 1994 Isuzu Rodeo with the 3.2L V6. It has been sitting for quite some time and now I cant get it running. I have replaced the Fuel Pump and Filter, new plugs, fresh gas. I have good

spark and ample fuel pressure. The car fires with starter fluid. The injectors do not appear to be pulsing. The plugs come out dry after attempts to start. I have checked grounds and any connections I can think of.

The pump and filter were replaced due to lower pressure at the fuel rail.
No codes from the port. Recieved all clear dtc 12. The car does not have a working alternator on it but all start attempts have been on a fully charged battery with a jump from a running vehicle connected.
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Lotsaboost
October 27, 2011.




Check to confirm that the injectors are not getting power. IF they are not, you need to trace the wiring back to the computer checking for wiring issues, corrosion. If it has set for a long time, chances are there is a corrosion problem.


The injectors are getting 12 volts with the key on.


Tiny
Lotsaboost
Oct 27, 2011.
It sounds like either a short to power or a problem in the PCM.


Where is the ground for the injectors I should check? Is it directly at the ecm which is in the drivers side kick panel I would assume or is there somethin in the engine bay I should be looking at? Also could a lack of power due to not having an alternator be the issue? Could a bad fpr cause the injectors not to pulse in any way?


Tiny
Lotsaboost
Oct 28, 2011.
If you are not getting power to the injectors using a test light, a bad ground isn't the issue because you are creating your own with the test light. You either have a corrosion problem or the ECM is the problem.


Im am getting power to the injectors, I tested the connector with a voltmeter with the key on. 12 volts. Where should I look for a corrosion problem?


Tiny
Lotsaboost
Oct 28, 2011.
Okay, lets think this through. You need to check the injector resistance for me. You should have 11.8 to 12.6 ohms of resistance. Additionally, power to the injecters should not be constant. It should strobe on and off as the injectors. That is why I feel you either have a short applying power all the time or the ECM is bad. Take a look at the wiring schematic I attached. The power to the injectors comes from the ECM. I can't find the exact voltage they should be getting, but 12 volts sounds very high.


All the wires and grounds look okay. I traced as far as I could besides going into the firewall. Just to clarify, With multiport injectors doesn't the ecm strobe the Ground for the injectors? Constantly feeding them power. That had always been my understanding.


Tiny
Lotsaboost
Oct 28, 2011.
I will check the resistance when I can but its not easy to do on this vehicle because they are under the intake manifold.
AD


Tiny
Lotsaboost
Oct 28, 2011.
I will be on the search for a decently priced ecm. Also, It was my understanding that in a multiport injector vehicle, the ecm strobes the Ground for cycles not the power. They are fed constant power. Is this correct?


Tiny
Lotsaboost
Oct 28, 2011.

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