1989 b250 5.9

Car wasn't starting but would crank. I could hear fuel pump turn on. Pulled plug and held to ground, didn't see any spark - also someone else previously determined no spark (not sure how).

I loosened the booster to try and get access to the fusible links, and in the process was working around the ignition switch quite a bit. Now the starter isn't engaging.

I pulled the ECU and tried heating it up on my other cars engine (no hair dryer available) and that didn't seem to do anything.

I'm at a loss. Seems to me the fusible links are the only thing left, but I'm having a heck of a time getting them out from behind the booster. Is there a way to check the ignition switch?
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Figured out the ignition wasn't working because I reinstalled it incorrectly. Now I can get the engine to crank again but still no spark. Replaced the coil, that didn't change anything. Thinking the hall effect sensor may be a problem, otherwise fusible link or ECU. Guess I'll spend more time trying to get the booster off so I can access the fusible links tomorrow.

 

Connected meter to -/+ of coil and cranked the engine, didn't get any readings. Is this the correct way to see if coil is getting power? Also checked spark plug but holding it to the block, no spark.

Checked asd relay at pin 30 and 86, connecting the pin to positive on meter and meter neg to battery neg. Both pins have 12.2v.

Heated the ECU up till it was warm to touch on back of case, almost too warm to touch. No change. Fuel pump kicks on, engine cranks, but no spark. Haven't checked fuel pressure yet.

Still trying to get the booster loose enough so I can access the fusible links, they are really snug back there.

Any help is appreciated!

 

Not exactly, The - negative is the trigger(when the coil sparks). Put the positive from the meter on the positive on the coil and then battery negative. I believe the ASD relay supplies power to the coil so the ignition must be on. If you have power there test the( -)on the coil(trigger) the same way but positive lead from meter on positive battery terminal and negative on coil. You must crank the motor and see if you see pulsating voltage, If so it's working. Best to use an analog meter because most digital ones don't work well reading that fast.

 

Good call, thanks!

It checked out. I then followed some procedures I found online for testing the distributor (don't have link, it was on my phone). That involved testing the two leads off the distributor that run from the pickup by setting the reader to AC and watching for a read out cranking the engine - I didn't get anything. Resistance between them when engine was off was about 1.5k.

Through chasing that down, and going to the store to get a new distributor, I learned my motor isn't an 89. Apparently the 89 5.9s have two leads from the distributor points, mine has three...which it looks like showed up in 1990 5.9s. Best I can tell harness is factory.

I'm going to try swapping on a new distributor pickup tomorrow.

Managed to get the booster out of the way today, all of them checked out.

Recap - things that have been tested:
-Grounds (all are good)
-Fusible links (fine)
-ASD relay (has power at pins 30 and 86)
-Coil (replaced, also has power on positive stud with ignition on)
-Fuel pump (I jumped the ASD and can clearly hear the fuel pump running the whole time. I have not checked pressure yet, not sure how or where)
-Spark (no spark)
-ECU (heated it up several times, no change)
-General electrical things (I've gone over all exposed components, all look good)

Any other thoughts on things to check? Running out of time to get the parts and get this thing rolling.

 

Turned out to be the coil pickup, which luckily was replaceable since the engine on my van is apparently newer than 89. Wish I tested that before going to the trouble to pull all the fusible links out...

 

glad you found it