1991 Ranger with 4.0 swap No Start

[trashtruck]

as the engine cranks, the crank sensor should supply voltage to the icm on pins 4 & 5. the crank sensor may supply ac or dc voltage, i can't remember. the icm should then supply voltage from pin 4 to the pcm, pin 16. the pcm would then ground pins 58 & 59 to fire the injectors and send spout signal back to icm on pin 2. this is my understanding.

 

[trashtruck]

it should be noted that the spout signal is not necessary to run but without it engine will be defaulted to 10 deg btdc or limp mode.

 

[mymmeryloss]

Ok i went and got a noid light and its not lighting up when cranking. Gonna start testing wires that you mentioned. Getting closer. I know it's something simple and im sure ive wasted a bunch of money but atleast i have all new electrical components.

Thanks again for the continued help!

 

[trashtruck]

when my 92 refused to start it took me most of a week to find out the wire crimp had failed inside the crank sensor connector so testing individual components is only half of it. you need to check connectors and wiring as well.

 

[mymmeryloss]

when my 92 refused to start it took me most of a week to find out the wire crimp had failed inside the crank sensor connector so testing individual components is only half of it. you need to check connectors and wiring as well.

Thats where im at right now. Cleaning and checking connections and putting some dielectric grease on connections. Wont be able to test a lot of things until i can get a buddy over here to help me out unfortunately.

 

[mymmeryloss]

So ive been throwing around the idea of the cam sensor. Most of the research i have done says there is no cam sensor. The Haynes says there is a cam sensor. That definitely controls the injectors. Any thoughts on this?

 

[larrydd999]

mymmeryloss, I have a Ford wiring diagram for a '92 Explorer that does not show a cam position sensor (CMP), and a 1994 Ford Explorer Vacuum & Electrical Troubleshooting manual that does show a CMP. From this and other references that I've read on this forum I believe the '91-92 engine does not have one. If you do (Ranger engines may be a bit different) then according to the '94 manual it is vital that it be working during startup in order to fire the injectors. If present, it's located at the rear of the engine behind the intake manifold and is hard to see, let alone work on.

 

[trashtruck]

I don't believe a 91/92 had a cam sensor. the distributor was replaced with an oil pump drive gear and timing is determined from the crank sensor alone.

 

[mymmeryloss]

Well the engine sits so close to the firewall that i cant see if there is one or not. So ive started pulling the intake mani to get a better look.

I will return and let you know if there is one or not.

 

[trashtruck]

have you tried spraying starting fluid in the intake to see if the motor will try to catch?

 

[mymmeryloss]

have you tried spraying starting fluid in the intake to see if the motor will try to catch?

Yes it will start with ether. Pretty sure i mentioned that.

 

[trashtruck]

ok, missed that, sorry. so I think your down to this: either the icm isn't getting a signal from the crank sensor or the pcm isn't getting a signal from the icm. try this, with a multi meter either back probe the icm connector or remove it from the icm. turn key to run but not start. black tester probe to ground and red probe to pins 5 then 6. jump the starter solenoid with a screwdriver to crank the engine. if there is voltage on both pins then the crank sensor is working.

 

[mymmeryloss]

Ok well i wanted to let you guys know what i got figured out on the truck.

So after pulling the intake manifold to see behind the engine, i can confirm there is no cam sensor on this engine.

So at that point i had had it and loaded the truck on a trailer and took it to a reputable mechanic. He had the truck for over two weeks and finally concluded that the replacement icm i got was faulty. He changed it and it fired right up and drives like new. Hopefully that fixes it for good! Just in time for summer!

 

[damnford]

them icms' are not cheap.

 

[410Fortune]

$108-133 on rockauto
I'm shocked you can still buy them new!

1991 FORD EXPLORER 4.0L V6 Ignition Control Module (ICM) | RockAuto

4 year old thread
$133 is cheap if it gets your 4.0 swapped ranger that you cannot get to run, running.............