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Hoping this is a simple issue. I just picked up a 99 1500, was supposed to run and drive good ect. When I got there to pick it up it wouldn't start. Cranks over fine and fires on starting fluid but won't stay running. We worked out a deal and I still brought it home.

Checked fuel pressure and I have 48psi at the rail. Still runs on starting fluid but won't stay running on its own. All fuses and relays are good.

No check engine light at all. Put scan tool on and read data, there is a line that says "fuel allowed" that says "no" any idea what causes that? The attached pic is from my Dakota for reference where it says "yes".

Any help is appreciated!

129870
 

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Put scan tool on and read data, there is a line that says "fuel allowed" that says "no" any idea what causes that? The attached pic is from my Dakota for reference where it says "yes".
Emergency fuel shutoff tripped?
I believe that's what in the car repair biz is called a WAG otherwise known as a wild-ass guess...
:unsure:
 

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Discussion Starter #4
Emergency fuel shutoff tripped?
I believe that's what in the car repair biz is called a WAG otherwise known as a wild-ass guess...
:unsure:
I was thinking that... but when I was trying to figure out where to find it to reset it everything I found said it doesn't have one... I might have to look for one on it again...
 

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Did someone change the PCM to one with anti theft?
I don't think so... but is there a way a guy could check for sure? The pump cycles and runs, builds pressure at the rails pcm just doesn't seem to want to fire the injectors. I was going to try a cam sensor but didn't figure that would be setting "fuel allowed" to no before even cranking...
 

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I was thinking that... but when I was trying to figure out where to find it to reset it everything I found said it doesn't have one..
I think it's correct that there is no inertia triggered fuel cutoff like on some vehicles (Fords have one I'm told), but I think there is an ASD (AutoShutDown) relay somewhere that can trip for a variety of reasons.
Though since the engine fires with starting fluid but won't run, you must be getting spark and I think—but I'm not sure—the ASD relay cuts ignition power as well as injector power when tripped, so that might not be it anyway.
 

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Easiest way to check the crank and cam sensors is to disconnect the battery, then try to start it and then check for codes.
The other way is with a scanner.
Scanner might show an anti theft screen - some do some don't.
 

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I think it's correct that there is no inertia triggered fuel cutoff like on some vehicles (Fords have one I'm told), but I think there is an ASD (AutoShutDown) relay somewhere that can trip for a variety of reasons.
Though since the engine fires with starting fluid but won't run, you must be getting spark and I think—but I'm not sure—the ASD relay cuts ignition power as well as injector power when tripped, so that might not be it anyway.
And it will continue to run as long as you keep feeding it starting fluid so spark doesn't seem to be an issue at all. I can watch the asd relay on the scanner and it acts as it should, shuts off after a couple seconds of key on no cranking and turns back on when you crank it over. Also swapped with known good relays.
 

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Easiest way to check the crank and cam sensors is to disconnect the battery, then try to start it and then check for codes.
The other way is with a scanner.
Scanner might show an anti theft screen - some do some don't.
Both the tach and scan tool register rpm when cranking... is it the crank sensor that it gets rpm from? I've had the battery disconnected several times in hopes of resetting something, and also leave it unhooked when I'm not working on it just so I don't come back out to a dead battery. Never any codes even after cranking for some time. I hadn't seen any anti theft on the scanner but I also haven't checked for any body codes yet either maybe I'll play with that tonight.
 

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Ok, then probably both cam and crank sensors are working.
Did you ever measure if there is any voltage going to the injectors?

Does it ever start for like 5 sec. and then shut off? Without additional assistance?
 

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IF the wiring is like my 2001 Dakota was -
The wire coming out of the ASD relay should have Batt voltage on when closed and should be a Dark Green w/ Orange tracer - THAT DG/OR wire goes to the coil and the injectors.
So if you cycle the ASD relay via the scan tool you should see the Batt voltage at the coil and the injectors.
The ground side of the injectors is controlled by the PCM.

So try to see if you can see battery voltage at the injectors when cranking or using the scan tool - if you can then you have the PCM stopping them from firing.
IF you can't you have a wiring issue, most likely in the PDC as it goes through that - ON MY 2001 Dakota wiring diagram, I do not know how similar or different yours might be, check the wire color.as mopar used DG/orange tracer for years on that circuit.
 

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Try giving it gas with the pedal pressed when cranking. Sounds like the IAC is not working or clogged. Remove the throttle body and clean all the carbon out of it with attention to the idle ports.
 

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Discussion Starter #13
Ok, then probably both cam and crank sensors are working.
Did you ever measure if there is any voltage going to the injectors?

Does it ever start for like 5 sec. and then shut off? Without additional assistance?
Just got out there to look at it again this morning... I get voltage to the injectors when the asd turns on when you first turn the key on. I'll have to get the wife out there later to see if they get voltage while cranking but I'd guess they do because the asd should be working properly. Never even tries to fire unless you give it starting fluid.
 

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Discussion Starter #14
IF the wiring is like my 2001 Dakota was -
The wire coming out of the ASD relay should have Batt voltage on when closed and should be a Dark Green w/ Orange tracer - THAT DG/OR wire goes to the coil and the injectors.
So if you cycle the ASD relay via the scan tool you should see the Batt voltage at the coil and the injectors.
The ground side of the injectors is controlled by the PCM.

So try to see if you can see battery voltage at the injectors when cranking or using the scan tool - if you can then you have the PCM stopping them from firing.
IF you can't you have a wiring issue, most likely in the PDC as it goes through that - ON MY 2001 Dakota wiring diagram, I do not know how similar or different yours might be, check the wire color.as mopar used DG/orange tracer for years on that circuit.
I've been comparing to my Dakota some as well. I'll follow more of the wireing and clean all the grounds for good measure tonight or tomorrow and see where that gets me. I'm afraid it might be something in the pcm because of that "fuel allowed" line, and I can't really find any troubleshooting for things that cause that to come up as "no" instead of "yes." The dakota just always says "yes"
 

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It does sound like that is the problem.
Other than anti theft - which should still let it start for a few seconds - that I can think of that shuts the fuel off is a bad TPS to where it thinks the throttle is floored. What is the TPS reading on the scanner and does it change with pedal movement.
What is the baro reading also?

The ground side of the injector circuits is the PCM, so if you have 12 V to the injectors that side should be fine.
 
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