engine cranks but doesn't start
03-19-2012, 06:35 PM
#22
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Location: Central Florida, Land of the Giant Rat.
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Okay, now check for fuel, if you have no fuel either, then it may be the crank/cam sensors or their harnesses/connectors, or it may be the ecu doesn't have power.
Could be as simple as a connector not plugged in. (Hope,hope,hope)
If we have fuel, then it's time to check the secondary ignition. Coils, power/signal to coils.
Make absolutely sure the plug you test is grounded well. I couldn't tell in the vid. [good lord I'm getting old. Increased mah screen size, you gots a jumper-cable to ground it! okay.]
Oops! on edit: I didn't notice your last post on pg 1!
You know you don't have fuel/spark, so it isn't likely the secondary ign or fuel system since those were working before the engine r&r. It doesn't completely rule out those systems, just gives us a place to go to for now.
Somebody here should know where to check in the harness to see where the 12v and ground are for the ecu. Check for it at the harness. If we have power/ground there, then we need to check for engine to ground with an ohmmeter.
Also with the meter you can unplug the ecu and cam/crank sensors and check for continuity between the ecu harness and the sensors. This will rule out the harnesses.
Don't put the meter on the ecu pins at all. Those li'l things are not happy with funky currents they're not designed for. Drivers are sensitive.
Could be as simple as a connector not plugged in. (Hope,hope,hope)
If we have fuel, then it's time to check the secondary ignition. Coils, power/signal to coils.
Make absolutely sure the plug you test is grounded well. I couldn't tell in the vid. [good lord I'm getting old. Increased mah screen size, you gots a jumper-cable to ground it! okay.]
Oops! on edit: I didn't notice your last post on pg 1!
You know you don't have fuel/spark, so it isn't likely the secondary ign or fuel system since those were working before the engine r&r. It doesn't completely rule out those systems, just gives us a place to go to for now.
Somebody here should know where to check in the harness to see where the 12v and ground are for the ecu. Check for it at the harness. If we have power/ground there, then we need to check for engine to ground with an ohmmeter.
Also with the meter you can unplug the ecu and cam/crank sensors and check for continuity between the ecu harness and the sensors. This will rule out the harnesses.
Don't put the meter on the ecu pins at all. Those li'l things are not happy with funky currents they're not designed for. Drivers are sensitive.
Last edited by RattleTrap; 03-19-2012 at 07:06 PM.
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03-19-2012, 07:24 PM
#23
Okay, now check for fuel, if you have no fuel either, then it may be the crank/cam sensors or their harnesses/connectors, or it may be the ecu doesn't have power.
Could be as simple as a connector not plugged in. (Hope,hope,hope)
If we have fuel, then it's time to check the secondary ignition. Coils, power/signal to coils.
Make absolutely sure the plug you test is grounded well. I couldn't tell in the vid. [good lord I'm getting old. Increased mah screen size, you gots a jumper-cable to ground it! okay.]
Oops! on edit: I didn't notice your last post on pg 1!
You know you don't have fuel/spark, so it isn't likely the secondary ign or fuel system since those were working before the engine r&r. It doesn't completely rule out those systems, just gives us a place to go to for now.
Somebody here should know where to check in the harness to see where the 12v and ground are for the ecu. Check for it at the harness. If we have power/ground there, then we need to check for engine to ground with an ohmmeter.
Also with the meter you can unplug the ecu and cam/crank sensors and check for continuity between the ecu harness and the sensors. This will rule out the harnesses.
Don't put the meter on the ecu pins at all. Those li'l things are not happy with funky currents they're not designed for. Drivers are sensitive.
Could be as simple as a connector not plugged in. (Hope,hope,hope)
If we have fuel, then it's time to check the secondary ignition. Coils, power/signal to coils.
Make absolutely sure the plug you test is grounded well. I couldn't tell in the vid. [good lord I'm getting old. Increased mah screen size, you gots a jumper-cable to ground it! okay.]
Oops! on edit: I didn't notice your last post on pg 1!
You know you don't have fuel/spark, so it isn't likely the secondary ign or fuel system since those were working before the engine r&r. It doesn't completely rule out those systems, just gives us a place to go to for now.
Somebody here should know where to check in the harness to see where the 12v and ground are for the ecu. Check for it at the harness. If we have power/ground there, then we need to check for engine to ground with an ohmmeter.
Also with the meter you can unplug the ecu and cam/crank sensors and check for continuity between the ecu harness and the sensors. This will rule out the harnesses.
Don't put the meter on the ecu pins at all. Those li'l things are not happy with funky currents they're not designed for. Drivers are sensitive.
I'm sure all the grounds are in.
I replaced the ground strap with a 4gauge wire, would this cause any of the issues?
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03-19-2012, 07:38 PM
#25
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Not really. It should be mo' better electrically than the stock strap.
I'm assuming your engine ground goes to the stock body ground location?
Do you have a good chassis to battery ground as well?
I'm assuming your engine ground goes to the stock body ground location?
Do you have a good chassis to battery ground as well?
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03-19-2012, 08:36 PM
#26
Is there anyway to test the ground to make sure it's correct?
I checked all of them, they are all in their default locations, and they are on tight.
Used a multimeter and checked the plugs, and power is going everywhere, so I'm guessing the harness is good.
I never messed with the chassis to battery harness, should be whatever was stock.
Anyway of testing the sensors to narrow it down?
I checked all of them, they are all in their default locations, and they are on tight.
I never messed with the chassis to battery harness, should be whatever was stock.
Anyway of testing the sensors to narrow it down?
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03-19-2012, 10:30 PM
#27
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Location: Central Florida, Land of the Giant Rat.
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You could connect the meter to the crank/cam sensor itself, on ac volts and see if the sensor generates any voltage during cranking. The sensor should also have an impedance, but I don't know how much.
There is also a 'gap' for the cas. Needs to be pretty close for the sensor to work.
What do you mean by 'power is going everywhere'?
You have 12v at the connector to the ecu?
There is also a 'gap' for the cas. Needs to be pretty close for the sensor to work.
What do you mean by 'power is going everywhere'?
You have 12v at the connector to the ecu?
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03-19-2012, 11:05 PM
#28
You could connect the meter to the crank/cam sensor itself, on ac volts and see if the sensor generates any voltage during cranking. The sensor should also have an impedance, but I don't know how much.
There is also a 'gap' for the cas. Needs to be pretty close for the sensor to work.
What do you mean by 'power is going everywhere'?
You have 12v at the connector to the ecu?
There is also a 'gap' for the cas. Needs to be pretty close for the sensor to work.
What do you mean by 'power is going everywhere'?
You have 12v at the connector to the ecu?
I'll check on the gap tomorrow, see if its good, I'm pretty sure it is going down as much as it can tho.
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03-25-2012, 10:18 PM
#30
Im having the same bad luck with mine after a recent engine swap, except mine starts. Mine will fire, rev to 2k or so, then immediately die. I've replaced the ecu, coilpack, filter, pump, injectors, fpr, and still does the same. Im about to just burn it. Hopin' to see a few things in here that I may not have tried!
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03-26-2012, 03:15 AM
#31
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Join Date: Oct 2010
Location: Central Florida, Land of the Giant Rat.
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Am I on candid camera?
Okay. Imp has no fuel/no spark. Do you have any codes at all? I'm staring to think power to the ecu, or the ecu. Don't rush out to buy one just yet. Does the pump prime when you first turn the key?
Nix, does it only die above two K, or will it idle all day or what? Also, codes?
If it's dying above two K only I'd wonder about two things first. Fuel supply and timing. Mechanical (Cams to crank) and ign timing. Upon re-reading you situ, Is your fuel pump running with the key in run engine running? Might try jumping the FP relay and seeing what happens...
You both could use a breakout box and a scope...
Okay. Imp has no fuel/no spark. Do you have any codes at all? I'm staring to think power to the ecu, or the ecu. Don't rush out to buy one just yet. Does the pump prime when you first turn the key?
Nix, does it only die above two K, or will it idle all day or what? Also, codes?
If it's dying above two K only I'd wonder about two things first. Fuel supply and timing. Mechanical (Cams to crank) and ign timing. Upon re-reading you situ, Is your fuel pump running with the key in run engine running? Might try jumping the FP relay and seeing what happens...
You both could use a breakout box and a scope...
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