2.3L ('83-'97) 1990 2.3 DIS issue

[Juddys123]

Hello, I’m new to this thread and am currently living in Musella Ga. I work as a heavy duty diesel tech but spend most of my free time turning wrenches on my own stuff. Back in December of last year I hit a deer in my 1990 Ranger shortbed with 2.3 and 5 speed. After installing a new front clip and repairing the body damage I found that the truck had a no spark issue.

I checked everything, I have power to the icm and both coils. Ground to the icm shows 8.5 volts instead of the usual 10-12 and I don’t know if this is problematic. However, my main issue is that I can’t get a good signal from my crank sensor. From what I’ve read the signal should go from 11-12 and then drop to 0 rapidly while the engine turns over.

Strangely I get a constant .25 volts from the crank sensor wire that feeds into the top of the icm and .52 volts at the CID wire. I replaced both the crank sensor and the harmonic balancer and this did not fix my issue. At this point I suspect a continuity issue within the harness but I’ve narrowed it down to either that or the icm. Any help would be appreciated.

 

[scotts90ranger]

Has it ran at all since you hit the deer? If not, have you checked the inertia switch in the passenger side footwell by the transmission tunnel? When I got in a wreck on my '97 it was tripped AND unplugged. I've been in a minor fender bender with no damage to either vehicle and had that trip on my '90

 

[Juddys123]

Has it ran at all since you hit the deer? If not, have you checked the inertia switch in the passenger side footwell by the transmission tunnel? When I got in a wreck on my '97 it was tripped AND unplugged. I've been in a minor fender bender with no damage to either vehicle and had that trip on my '90

the moment I hit the deer the truck cut off but I was able to crank the truck back up and drive off to a side road. I checked the inertia switch previously and I can hear my fuel pump turn on with good pressure at the fuel rail. My understanding was that the inertia switch had no impact on ignition system. I also conducted a 50/50 test to start off with which resulted in no spark and led me to believe I was having ignition issue

 

[scotts90ranger]

Could not work but maybe try swapping the two coil packs as only the passenger side is used during cranking, do you have injector pulse? It's driven out of the crank sensor signal to the DIS module as well...

 

[Juddys123]

Could not work but maybe try swapping the two coil packs as only the passenger side is used during cranking, do you have injector pulse? It's driven out of the crank sensor signal to the DIS module as well...

I’ll try doing a pulse test at the injectors next week but I’m really scratching my head about the cause of the strange voltage readings at the crank sensor

 

[scotts90ranger]

The crank sensor is hall effect on these, the sensor output (I think there's two signals with the two vanes...) should switch on and off depending on if there is metal in the way or not, some hall effect sensors have some "pull up" or "pull down" voltage or ground on the signal to help processing. In the 24 years I've had the '90 the only ignition system issue I've ever had is the one crank sensor that went out, and the other was a self induced deal where I didn't ground the DIS module (the 3 bolts that mount it) after I did the turbo swap, if I was to do it now I would do it different and wouldn't have scrapped the two engines I had...

 

[Juddys123]

The crank sensor is hall effect on these, the sensor output (I think there's two signals with the two vanes...) should switch on and off depending on if there is metal in the way or not, some hall effect sensors have some "pull up" or "pull down" voltage or ground on the signal to help processing. In the 24 years I've had the '90 the only ignition system issue I've ever had is the one crank sensor that went out, and the other was a self induced deal where I didn't ground the DIS module (the 3 bolts that mount it) after I did the turbo swap, if I was to do it now I would do it different and wouldn't have scrapped the two engines I had...

Ok so I have constant 12 volts at both injector wires. I assume this means that the pcm isn’t closing and opening the circuit due to some crank sensor issue?

 

[Shran]

You should have nothing at the injectors unless the engine is cranking or running, that's weird that you're seeing constant voltage there.

I believe you should be seeing AC voltage at the crank sensor, not DC. Hard to test that with a digital multimeter, way easier with a scope or analog meter.

Where is the DIS module located, IIRC it is behind the power steering pump in that area? On other trucks it is next to the radiator, pretty easy to damage it there during a collision or mess up the wiring.

 

[Juddys123]

l

You should have nothing at the injectors unless the engine is cranking or running, that's weird that you're seeing constant voltage there.

I believe you should be seeing AC voltage at the crank sensor, not DC. Hard to test that with a digital multimeter, way easier with a scope or analog meter.

Where is the DIS module located, IIRC it is behind the power steering pump in that area? On other trucks it is next to the radiator, pretty easy to damage it there during a collision or mess up the wiring.

the dis module is bolted and grounded to the intake.

 

[scotts90ranger]

There is a constant power wire to all injectors, I believe the ground is switched, are you checking across the injector connector or from a ground to the wires?

Sometimes with stuff like that there is a test signal sent through so you will see some voltage across without the injector in the circuit, that's where a noid light or test light comes in handier in some instances...