Truck starts but quits running in 2 seconds.
#1
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Truck starts but quits running in 2 seconds.
I have checked the fuel pressure from the pump, and that shows 40 psi. I checked the diagnostic code from the check engine light. The code given is "12" (RPM signal) No Ne and G signal to ECU within 2 seconds after starting. Fault area suggested in Haynes manual is distributor circuit, distributor, starter signal circuit or ECU. I checked the pickup coil ohms/resistance and that is within tolerance. The coil has been checked and also swapped out with a new coil. The resistance in the coil is good and the new coil did not help either so the old coil was put back in. Now I am suspecting the igniter on top of the coil but there is no diagnostic approach in the Haynes manual to check it to see if it is bad or good. Any suggestions?
Thank you,
Steven
1988 SR5 22re EFI non turbo
stevenbrick@hotmail.com
Thank you,
Steven
1988 SR5 22re EFI non turbo
stevenbrick@hotmail.com
Last edited by stevenbrick; 01-07-2009 at 02:02 AM. Reason: clarification on fault suggestion in Haynes manual
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I found that if the mass air flow or air box is not in place that it will do that. The mass air flow has a flapper that sends a signal to the fuel pump, with little info of what you have done I'm not sure.
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Ok, I will get a test light for the injectors. I tried the diagnostic bypass jumper for the MAF but that did not make it run yesterday. The motor will run if I spray starter fluid up the throttle body throat. This tells me I think, that the ignition system is in good shape, but I agree that the fuel injectors are not squirting.
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"...diagnostic bypass jumper for the MAF..."? (I think you meant AFM-air flow meter but that's just semantics.) What jumper? Do you mean jumpering the fuel pump terminal in the diagnostic connector to activate the pump? Also, (and you probably know this) you have to have the duct from the throttle body to the AFM connected or it will not turn the fuel pump on.
The code gives you a good idea of what's wrong: the ECU is not getting the signal from the distributor signalling the engine is turning. The ignitor is aware the engine is rotating which is why it will run with starting fluid, but the signal is not being passed to the ECU for some reason. The ECU will not fire the injectors if it doesn't receive that signal and this is why the engine dies after a couple seconds. The cold start injector is supplying enough fuel for the engine to start and the ignitor is firing the plugs. But since the ECU doesn't get the NE signal the injectors are not triggered because the ECU cannot determine the engine rpms, how much fuel to inject and when to fire them.
The code gives you a good idea of what's wrong: the ECU is not getting the signal from the distributor signalling the engine is turning. The ignitor is aware the engine is rotating which is why it will run with starting fluid, but the signal is not being passed to the ECU for some reason. The ECU will not fire the injectors if it doesn't receive that signal and this is why the engine dies after a couple seconds. The cold start injector is supplying enough fuel for the engine to start and the ignitor is firing the plugs. But since the ECU doesn't get the NE signal the injectors are not triggered because the ECU cannot determine the engine rpms, how much fuel to inject and when to fire them.
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"you have to have the duct from the throttle body to the AFM connected or it will not turn the fuel pump on." is correct. The reason I posted that is because I tried to crank mine for a couple of hours before i remembered reading in the manual that the AFM supplied a signal to the fuel pump, or maybe it supplies it to the ECM first. I could shoot gas and ether in there and it would run for a few seconds then cut off. But I knew it would run because I already had it running before hand with the AFM connected. I knew it was something simple. It sounds like a fuel problem, If your pump is pumping fuel it could be injectors but bypassing the MAP or AFM or even trying a known good would not be a bad idea. There again I could be totally off on your problem. Abecedarian seems to be on the right track.
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Also try removing the air filter, if there isn't enough air moving across the AFM to move the flap the pump might not be getting a signal. Try verifing that the pump is pumping fuel and you have the correct fuel pressure at the injectors .
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I ohmed out the AFM?
I used my multi-meter to ohm out the AFM. The resistance readings I measured on the AFM tabs were all infinity (an open condition) instead of what my Haynes manual was showing I should measure. I am going to replace the AFM and let you folks know what happens. Thank you for all the great suggestions. I thought MAF stood for Mass Air Flow sensor but I guess I should have said AFM for Air Flow Meter? Sorry for confusion!
Steven
Steven
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heck with haynes. do this:
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml
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heck with haynes. do this:
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml
http://www.4crawler.com/4x4/CheapTricks/AFM/index.shtml
edit: My eyes were cold. I thought the "drama llama" smiley said good posting.
Last edited by toyota4x4907; 01-06-2009 at 04:21 PM.
#18
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The flow through type found on most newer models, most simply called "Mass Air Flow" sensor, or MAF, have just a sencor that sits directly in the flow of air, and measures the amount of passing air that way. It causes less restriction in the air flow, and there's no moving parts so there's less to break.
Ironically though, both are pretty pricy to replace
let us know how it turns out!
Last edited by iamsuperbleeder; 01-06-2009 at 04:19 PM.
#19
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You can run around and check a little of this and alittle of that and not get to anywhere. You can even start pulling and replacing parts left and right but never solve the problem. Three things are needed for an engine to run fuel, air, and fire. Now start narrowing it down.
#20
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You can run around and check a little of this and alittle of that and not get to anywhere. You can even start pulling and replacing parts left and right but never solve the problem. Three things are needed for an engine to run fuel, air, and fire. Now start narrowing it down.
it's obviously got fire if it runs for a second
aparently, fuel and air are presesnt as well (for a limited time obviously), because as you claimed, an engine just wont run without them; since it does fire up for a couple seconds, then I guess they're there
but the "2 second run" sounds typical of a malfuctioning or disconnected AFM
go unplug yours, I bet it'll do the exact same thing as what he describes
Last edited by iamsuperbleeder; 01-06-2009 at 06:01 PM.