Starts and dies; relays; Ignition switch; headlights, dimmer

[bilgamesh]

My 90, with 4.0 L automatic is having starting problems. It started out that about one in ten times I would go start it, the starter would crank, the engine would fire like it was going to start, and then it would not start. This has gotten progressively worse so that there are times when I may have to crank it 20 times to get it to start. Today I ran the battery down with this.

 

My ignition switch and key cylinder had too much play, and the key would come out while the truck was running, so I set about replacing these in the hope it would solve the other problem. It didn't, and I have inadvertantly somehow incapacitated my high beam switch. The switch works, but the actuator in the column is probably out of position somehow. I will have to fix that later too. Anyway, the new switch and cylinder did not help the starting problem.

 

I removed and cleaned up the idle air control valve, though it was not exceedingly dirty. I also jumpered across the ballast resistor to no effect.

 

I am trying to figure out my next step while my battery is charging...

 

Update: After charging my battery for 30 minutes, it started up 10 times in a row. It is tempting to think this is battery related, but during the times when it won't start, it shows no signs the battery is low or bad.

 

Any thoughts? - Thanks

 

Solution confirmed 12/24/2008:

During work on this problem, I did several things which cascaded into more problems. I am detailing the solution here with the end in mind that someone may benefit at some point. After messing with the Idle Air Control Switch and the Ballast resistor and troubleshooting for a couple weeks, I replaced the ignition switch to no effect. During this repair, my instrument panel lights stopped working, so I replaced the light switch. This fixed my panel lights, but my dimmer switch stopped working. It would not stay on bright. I went out to drive that night and noticed my headlights would not work at all. I dug back into the dash and found that the hot wire had come out of the junction block on the light switch and was hanging. Once I reconnected it, the headlights and the dimmer worked. To fix the starting problem, after running the battery down one day, and re-charging overnight, I noticed that with a really hot charge, the truck started every time. I began to suspect a problem in the fuel pump circuit. Once I could duplicate the problem again, I started swapping around some of the relays along the passenger fender and found the problem went away. I bought a new relay for $6 at Autozone, swapped it in and out until I was convinced I found the bad one, and that the problem only happened when the bad one was in there. Evidently the fuel pump relay was faulty. I am happy to report everything is fixed! Thanks to everyone who replied with ideas and information.

[bilgamesh]

My 90, with 4.0 L automatic is having starting problems. It started out that about one in ten times I would go start it, the starter would crank, the engine would fire like it was going to start, and then it would not start. This has gotten progressively worse so that there are times when I may have to crank it 20 times to get it to start. Today I ran the battery down with this.

 

My ignition switch and key cylinder had too much play, and the key would come out while the truck was running, so I set about replacing these in the hope it would solve the other problem. It didn't, and I have inadvertantly somehow incapacitated my high beam switch. The switch works, but the actuator in the column is probably out of position somehow. I will have to fix that later too. Anyway, the new switch and cylinder did not help the starting problem.

 

I removed and cleaned up the idle air control valve, though it was not exceedingly dirty. I also jumpered across the ballast resistor to no effect.

 

I am trying to figure out my next step while my battery is charging...

 

Update: After charging my battery for 30 minutes, it started up 10 times in a row. It is tempting to think this is battery related, but during the times when it won't start, it shows no signs the battery is low or bad.

 

Any thoughts? - Thanks

 

Solution confirmed 12/24/2008:

During work on this problem, I did several things which cascaded into more problems. I am detailing the solution here with the end in mind that someone may benefit at some point. After messing with the Idle Air Control Switch and the Ballast resistor and troubleshooting for a couple weeks, I replaced the ignition switch to no effect. During this repair, my instrument panel lights stopped working, so I replaced the light switch. This fixed my panel lights, but my dimmer switch stopped working. It would not stay on bright. I went out to drive that night and noticed my headlights would not work at all. I dug back into the dash and found that the hot wire had come out of the junction block on the light switch and was hanging. Once I reconnected it, the headlights and the dimmer worked. To fix the starting problem, after running the battery down one day, and re-charging overnight, I noticed that with a really hot charge, the truck started every time. I began to suspect a problem in the fuel pump circuit. Once I could duplicate the problem again, I started swapping around some of the relays along the passenger fender and found the problem went away. I bought a new relay for $6 at Autozone, swapped it in and out until I was convinced I found the bad one, and that the problem only happened when the bad one was in there. Evidently the fuel pump relay was faulty. I am happy to report everything is fixed! Thanks to everyone who replied with ideas and information.

[Eagle]

CPS

 

 

CPS

 

 

CPS

 

 

CPS

[Eagle]

CPS

 

 

CPS

 

 

CPS

 

 

CPS

[oldrusty]

:agree: :agree: :agree: :agree:

[oldrusty]

:agree: :agree: :agree: :agree:

[bilgamesh]

Thanks for the replies guys, but just one more sanity check before I throw another part it this:

 

When I try to start it, I turn the key to the start position, the starter cranks, the engine fires, naturally when this happens I let off the key and it does not complete starting up. If instead I hold the starter engaged, I can rev the engine etc., but if I let the key off the start position back to the on position, the engine does not finishsh starting, and instead dies completely. This is why I thought it might be the ballast resistor.

 

Thanks

[bilgamesh]

Thanks for the replies guys, but just one more sanity check before I throw another part it this:

 

When I try to start it, I turn the key to the start position, the starter cranks, the engine fires, naturally when this happens I let off the key and it does not complete starting up. If instead I hold the starter engaged, I can rev the engine etc., but if I let the key off the start position back to the on position, the engine does not finishsh starting, and instead dies completely. This is why I thought it might be the ballast resistor.

 

Thanks

[Eagle]

Ah .. je comprends.

 

I agree, Although usually they'll run for 15 to 30 seconds after you let go of the key, as long as there's still some pressure in the fuel rail. It's easy to test -- just jumper across the two wires on the ballast resistor to bypass it. If it'll stay running ... you've found the problem.

[Eagle]

Ah .. je comprends.

 

I agree, Although usually they'll run for 15 to 30 seconds after you let go of the key, as long as there's still some pressure in the fuel rail. It's easy to test -- just jumper across the two wires on the ballast resistor to bypass it. If it'll stay running ... you've found the problem.

[GaruMJ]

here is explained how to check your CPS I agree with the guys about CPS. It is almost at the end of the page.

http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

[GaruMJ]

here is explained how to check your CPS I agree with the guys about CPS. It is almost at the end of the page.

http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

[bilgamesh]

I guess I will plan to dig into the CPS, but I can't help but think it sounds different from the symptoms posted with other CPS failures. This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position.

 

I just went out and started repeatedly with my freshly charged battery. With a really hot battery, my problem is apparantly gone. This is obviously not a fix, but may be good information in case anyone has other thoughts.

 

Thanks

[bilgamesh]

I guess I will plan to dig into the CPS, but I can't help but think it sounds different from the symptoms posted with other CPS failures. This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position.

 

I just went out and started repeatedly with my freshly charged battery. With a really hot battery, my problem is apparantly gone. This is obviously not a fix, but may be good information in case anyone has other thoughts.

 

Thanks

[Eagle]

This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position.

No, you are confusing your terminology.

 

"Turning over" is what you call "cranking" -- the starter motor is making the crankshaft rotate. "Turning over" does not mean "starting" or "running." If I understand correctly, you're saying it does start ... but won't run unless the key is in the START position.

 

You are correct -- if it reliably fires while the starter is engaged, but then dies when you release the key, the problem is more likely the ballast resistor, or the fuel pump. You can test the ballast resistor just by jumping the two wires together.

 

Remember what the ballast resistor does -- it reduces the voltage sent to the fuel pump. During a start, the resistor is bypassed and the fuel pump gats a full 12 volts. When you release the key, power to the fuel pump flows through the ballast resister, which drops it from 12 volts to 8 or 9 volts. What I'm thinking is this:

 

Usually, if the ballast resistor is bad, once the engine starts there should be enough pressure in the rail for the engine to idle for at least 15 to 30 seconds. You're saying it dies instantly. That suggests that maybe your fuel pump isn't putting out enough pressure (or volume), and it needs the full 12 volts just to deliver enough fuel to idel. Once the key is released and the fuel pump is only seeing 8 or 9 volts, it doesn't pump enough fuel to keep things cookin'.

 

Make any sense?

 

Another test for the ballast resister: After the truck has sat overnight, turn the key to ON but not to START. Do it with your door open and your head outside. You should hear the fuel pump run for about 5 to 10 secinds while it pressurizes the fuel rail, then it should shut off when it reaches pressure. If you don't hear the fuel pump at all -- think ballast resistor. If the pump runs and runs and runs and runs ... think either fuel pump or regulator.

[Eagle]

This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position.

No, you are confusing your terminology.

 

"Turning over" is what you call "cranking" -- the starter motor is making the crankshaft rotate. "Turning over" does not mean "starting" or "running." If I understand correctly, you're saying it does start ... but won't run unless the key is in the START position.

 

You are correct -- if it reliably fires while the starter is engaged, but then dies when you release the key, the problem is more likely the ballast resistor, or the fuel pump. You can test the ballast resistor just by jumping the two wires together.

 

Remember what the ballast resistor does -- it reduces the voltage sent to the fuel pump. During a start, the resistor is bypassed and the fuel pump gats a full 12 volts. When you release the key, power to the fuel pump flows through the ballast resister, which drops it from 12 volts to 8 or 9 volts. What I'm thinking is this:

 

Usually, if the ballast resistor is bad, once the engine starts there should be enough pressure in the rail for the engine to idle for at least 15 to 30 seconds. You're saying it dies instantly. That suggests that maybe your fuel pump isn't putting out enough pressure (or volume), and it needs the full 12 volts just to deliver enough fuel to idel. Once the key is released and the fuel pump is only seeing 8 or 9 volts, it doesn't pump enough fuel to keep things cookin'.

 

Make any sense?

 

Another test for the ballast resister: After the truck has sat overnight, turn the key to ON but not to START. Do it with your door open and your head outside. You should hear the fuel pump run for about 5 to 10 secinds while it pressurizes the fuel rail, then it should shut off when it reaches pressure. If you don't hear the fuel pump at all -- think ballast resistor. If the pump runs and runs and runs and runs ... think either fuel pump or regulator.

[bilgamesh]

if it reliably fires while the starter is engaged, but then dies when you release the key, the problem is more likely the ballast resistor, or the fuel pump. You can test the ballast resistor just by jumping the two wires together..

I already jumpered across the ballast resistor to no effect, so that is out!

 

What I'm thinking is this: Usually, if the ballast resistor is bad, once the engine starts there should be enough pressure in the rail for the engine to idle for at least 15 to 30 seconds. You're saying it dies instantly. That suggests that maybe your fuel pump isn't putting out enough pressure (or volume), and it needs the full 12 volts just to deliver enough fuel to idle. Once the key is released and the fuel pump is only seeing 8 or 9 volts, it doesn't pump enough fuel to keep things cookin'.

Insofar as this theory points toward the fuel pump, I think it is a possibility, however, since as you point out that there should be enough fuel to run a few seconds, AND when I jumper the wires, the fuel pump is getting the full 12 volts, it seems more like the fuel pump is struggling with or without 12 volts.

 

In any event, the fuel pump always runs for a moment when I turn the key. Whether or not it produces enough pressure during this phase and after, is unknown.

 

I think I recall reading here somewhere the fuel pump is a real pain to get off...

[bilgamesh]

if it reliably fires while the starter is engaged, but then dies when you release the key, the problem is more likely the ballast resistor, or the fuel pump. You can test the ballast resistor just by jumping the two wires together..

I already jumpered across the ballast resistor to no effect, so that is out!

 

What I'm thinking is this: Usually, if the ballast resistor is bad, once the engine starts there should be enough pressure in the rail for the engine to idle for at least 15 to 30 seconds. You're saying it dies instantly. That suggests that maybe your fuel pump isn't putting out enough pressure (or volume), and it needs the full 12 volts just to deliver enough fuel to idle. Once the key is released and the fuel pump is only seeing 8 or 9 volts, it doesn't pump enough fuel to keep things cookin'.

Insofar as this theory points toward the fuel pump, I think it is a possibility, however, since as you point out that there should be enough fuel to run a few seconds, AND when I jumper the wires, the fuel pump is getting the full 12 volts, it seems more like the fuel pump is struggling with or without 12 volts.

 

In any event, the fuel pump always runs for a moment when I turn the key. Whether or not it produces enough pressure during this phase and after, is unknown.

 

I think I recall reading here somewhere the fuel pump is a real pain to get off...

[comancheman]

pickup or borrow a fuel pressure gauge and check your pressure after the pump primes, during starting and while "running." it hooks up to the shrader valve on the fuel rail.

they usually arent much more than $20 and are a good thing to have in your tool box.

[comancheman]

pickup or borrow a fuel pressure gauge and check your pressure after the pump primes, during starting and while "running." it hooks up to the shrader valve on the fuel rail.

they usually arent much more than $20 and are a good thing to have in your tool box.

[Jacobs]

This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position.

No, you are confusing your terminology.

 

"Turning over" is what you call "cranking" -- the starter motor is making the crankshaft rotate. "Turning over" does not mean "starting" or "running."

 

I agree! Crank and start are the only two words you need to describe this problem. No crank, crank no start, etc. But, it seems like half the country uses the exact opposite terms. I think as long as parts of the mainland refer to a Dana 30 as a 'front rear end' we will continue to have these kinds of problems.

[Jacobs]

This thing is not just cranking with no attempt to start; it is turning over, but fails to keep running when the key is released from the start position.

No, you are confusing your terminology.

 

"Turning over" is what you call "cranking" -- the starter motor is making the crankshaft rotate. "Turning over" does not mean "starting" or "running."

 

I agree! Crank and start are the only two words you need to describe this problem. No crank, crank no start, etc. But, it seems like half the country uses the exact opposite terms. I think as long as parts of the mainland refer to a Dana 30 as a 'front rear end' we will continue to have these kinds of problems.

[jtdesigns]

Throwing this out here, but could it be a bad switch?

[jtdesigns]

Throwing this out here, but could it be a bad switch?

[deziped]

It sure sounds to me like its a problem in the switch down the steering column aways. When you turn the key all that does is move a connecting shaft/rod going to the elec switch itself. It possible when your backing the key out of the start position the switch, on down the column, is losing contact & cutting the elec flow. Out of curosity when the switch is in the run position are you getting electricity to things like the radio, fan blower, fuel guage etc.? :dunno: