No Spark - 87 ranger 2.9

[sattech2000]

Hi All,
Its late and i'm beating my head on this. my 87 ranger 2.9 has no spark. It started out with die'ng after about a half hour driving. Let it sit for an hour or two and it'll start right back up. So far ive replaced ignition module (twice), distributor, ignition coil, bypassed ECM relay. The last time I ran it, it died and now there is no spark at all thankfully! I hate intermittent problems.

I've verified and confirmed 5volts at TPS. Not sure what other pinpoints I can check. I'm brain dead at the moment and need an outsiders view. any thoughts are appreciated. Really starting to think ECM but I wan't to pinpoint and confirm via testing before I make that assumption. Anyone have a good diagnostics to check that for this problem?

 

[509lifted]

it is ur tfi on ur distributor mine did the same thing i changed it and it runs now

 

[RustedRanger]

I cleaned my coil wiring plug in one time then it wouldn't start,even though it looked fine it was bad. Might try "jiggling" it around to see if you get anything.

 

[sattech2000]

I've replaced the tfi twice, the second time was with a new distributor.
I've also replaced the coil. I've used electronic contact cleaner and small files on the coil connector with no change. I verified i'm getting 12volts to it. The connector looks like crap so I might just replace it anyways. I think i've jiggled and wiggled just about every wire I can find...even given a lotta 'love taps'

 

[adsm08]

Take a test light (any old light will work, just get a few connector tabs, some wire and use one of your headlights), plug it in in place of the ignition coil and crank the engine. If the light is flashing (may look like it dimming slowly) then you got a faulty coil.

If not, start looking at power and ground wiring. Coil should be always hot with the key on. Green and yellow wire should have alternating ground and nothing as the engine cranks.

The TFI is solely responsible for firing the coil in your system. The computer has nothing to do with it. Also check for power to the red wire at the TFI with the key on. If it isn't powering up you can't get spark.

 

[sattech2000]

I receive no response from test light while hooked to coil connector(green/yellow and red wires). The light works on the red to gnd wires so I know my equiptment is working and i'm receiving 12volts.

Test light connected from +12volts to green/yellow wire at tfi and no response. Pulled tfi and performend resistance test following instructions at http://www.therangerstation.com/tech_library/TFI_Diagnostic.html and the module fails.

I'm heading back to jimmy in the red vest for my third one in under five miles of drive time. The entire mounting surface is coated with heatsync compound when installed new. Am I missing something else here or just dealing with cheap ass parts? Will update when I get new module on.

 

[sattech2000]

scratch that. Module tested good 10 out of 10 times. Since the problem was present before replacing this last one I think i've ruled that out as the source of the problem.
Anyother thoughts?

 

[sattech2000]

Wheres that emoticon for beating my head against wall?
I just confirmend via swap testing the brand new distributor I installed failed after five minutes of use.

Now wheres that emoticon for the smiley face drinking a beer? I need about 12 of them....

 

[adsm08]

Wait, back up two steps here.

You have power to the coil, good.

Did you pull the connector off the TFI and test for ground? That won't give you a useable result. The proper (easiest) way to do that one is to hook the light to battery + and back-probe the coil connector. The green/yellow wire grounds THROUGH the TFI, so it has to be plugged in there or the test results are worth about as much as Russian money.

Next, did you ever check for power TO the TFI? You never said. If it's not powering up it's not going to work.

 

[sattech2000]

Sorry 'bout that, my second post above I said that I confirmed +12 at the coil. I did also confirm +12 at the tfi pin 3 with key on and pin 4 with switch in start position.

With the information you gave me...it put me on the track to go through this diagnostic procedure located at http://www.therangerstation.com/tech_library/TFI_Diagnostic.html

At the bottom it indicates temporarily jumpering the green/yellow wire to ground and watch for a spark from the coil. That worked. I then grounded the green/yellow wire at pin 2 of the TFI and a spark jumped again. confirming ignition coil and wiring was good.

I then suspected the pickup coil was not working so I put my old distributor back in and it fired right up....but shuts down after 20 minutes(original problem). Let it sit an hour or two and fires right back up. A warranty replacement distributor will be here this afternoon and I'm praying that solves the original problem.

 

[sattech2000]

Thank you for all the information and time you've given me. I was totally brain dead over the weekend and not thinking the process through clearly.