My Blue Burb had to piggy back on a roll back

[Lt.Del]

Well, they say there is a first time for everything.  My 1991 3/4 ton 4x4 5.7 sub  had to be towed today.  I went to the mall.  When I came back out, I started it up, drove it about 30 feet, then she died.  No warning, nothing.

The battery is strong and turns the engine quite fast.  It was too late in the night to check for spark and gas.  I'll do that within the next day or two.

I'm thinking fuel pump, but, it didn't sputter or nothing. I'll check for gas delivery when I can and also check for spark.

I hope i don't have to drop that dang tank.  


 

[k5blazerfan]

how full was the tank?

[Lt.Del]

i filled up the tank two days ago--around 30 gallons 

[fitz]

  If it's the fuel pump sometimes you can give the tank a good whack (hard to so if it has a skid plate) and it will work again for a short time.
  I know you got your truck home, but maybe this will help someone else.

[Lt.Del]

Ok, I was able to look at it for a few minutes today with my 5 yr old boy's help.  He turned the key while I checked for spark.

Verdict: It has no spark.  I took the distributor cap off to see if the rotor turns, which would rule out a broken timing chain.  Luckily, the rotor does turn.

I have 12 volts getting to the coil (via red wire) with key on.  The 12 volts gets through the coil to the red wire clipped onto the module at the distributor.    









My extra distributor which I may put in tomorrow (or just put this module on the distributor in the sub)


Now, my attention focuses on the module.  How can I tell if that is bad?  Of course, it could be the pick up coil too.

[85-bowtie]

You can pull that module off and run it to the parts store and they usually have a machine to check it out for you.

[Lt.Del]

I'm so happy.  I've been thinking about this all evening.  I couldn't wait til tomorrow.  So, at 9:30pm after I put my son to bed, I ran outside and grabbed my "other" distributor and took the module off of it.  I put that module on the distributor that is in my sub, screwed down the two screws, clipped the pickup coil wire in place, screwed down the distr.cap and, in a total time of about 10 minutes later, I cranked it and it sounded sooooo good.

It's weird how when the module goes, she goes, no sign, warning, nothing.  Kaput!  A $40 module, but, I had an extra one.  

[VileZambonie]

Don't waste your time having an autoparts store ever test a solid state module. It's usually the module that goes but Maybe this will help you all for future reference:





IGNITION SYS. CHECK (SEALED MODULE CONN. DIST.)

TEST DESCRIPTION : Numbers below refer to circled numbers on the diagnostic chart.



Two wires are checked, to ensure that an open is not present in a spark plug wire.
1A. If spark occurs with EST connector disconnected, pick-up coil output is too low for EST operation.

A spark indicates the problem must be the distributor cap or rotor.
Normally, there should be battery voltage at the "C", and "+" terminals. Low voltage would indicate an open or a high resistance circuit from the distributor to the coil or ignition switch. If "C" terminal voltage was low, but "+" terminal voltage is 10 volts or more, circuit from "C" terminal to ignition coil or ignition coil primary winding is open.
Checks for a shorted module or grounded circuit from the ignition coil to the module. The distributor module should be turned "OFF," so normal voltage should be about 12 volts. If the module is turned "ON," the voltage would be low, but above 1 volt. This could cause the ignition coil to fail from excessive heat. With an open ignition coil primary winding, a small amount of voltage will leak through the module from the "Bat." to the "tach" terminal.
Applying a voltage (1.5 to 8 volts) to module terminal "P" should turn the module "ON" and the "tach" terminal voltage should drop to about 7-9 volts. This test will determine whether the module or coil is faulty or if the pick-up coil is not generating the proper signal to turn the module "ON." This test can be performed by using a DC battery with a rating of 1.5 to 8 volts. The use of the test light is mainly to allow the "P" terminal to be probed more easily. Some digital multi-meters can also be used to trigger the module by selecting ohms, usually the diode position. In this position the meter may have a voltage across it's terminals which can be used to trigger the module. The voltage in the ohm's position can be checked by using a second meter or by checking the manufacturer's specification of the tool being used.
This should turn "OFF" the module and cause a spark. If no spark occurs, the fault is most likely in the ignition coil because most module problems would have been found before this point in the procedure. A module tester could determine which is at fault.

[4x4HighSierra]

I see that you found the problem which is good on your part.  But once i had the same problem the truck would idle but if i put it in drive and roll 20ft it would die.  I checked the red wire going to the distributor and it would be hot with the key on but when i had someone crank it it would not stay hot.  So i replaced the ignition module and all was good.

[Stewart G Griffin]

What brand coil was this?   And how old, approximately, was it?

[VileZambonie]

What brand coil was this?   And how old, approximately, was it?

He replaced the module not the coil

[Stewart G Griffin]

i meant the module

[Lt.Del]

i don't know  Stew, I bought a complete distributor a couple of years ago when i had issues.  Turned out my injector was messing up and it was not in the ignition.   I put the new distributor in the truck and pulled out the one in it and kept it as a spare.  Last night I just took the module off the distributor that came with the truck when i bought it (my extra distributor) and put it on the distr., that's in the truck and she's fine now.
I have no idea what make/manufacturer either is.  The module that went bad is only a  couple years old. 

[Irish_Alley]

One thing I hate about when testing electronics some times they would only test bad if warm.

[78silver]

I had similar HEI failures at 50k and 125k miles caused by failure of the rotor.  Fortunately, both times this happened, the truck was in my driveway,and I' call that considerate.  I now replace rotor and cap at 40k intervals.  With 230k miles total,however, the module soldiers on.