Crank position sensor

91 XR7

Registered User
Regarding the '89-93 crank position sensor.

Okay it has a B+(read ignition) lead, a Ground lead, and two signal output leads.

My question is this, the two output leads, are they spiced together inside the sensor or are they being supplied by separate hall effect sensors (even thou the area is reasonably small) ???

I'm just wondering if one circuit (for the EEC per say) is good, but the one for the DIS is becomes bad/opens once it has a chance to heat soaked?

One can look back to my posts about my '91 being hard to start only when it was hot and has sat for awhile. Almost every sensor has been replaced, except for the O2 sensors and the crank sensor which, even to this day, looks nearly brand new Ford piece.
But the upshift light does go out right then the engine starts to turn over, even when the engine has issues starting.

I've been craving to drive a manual trans car again, but this hot start BS is annoying, and if I can cure it I know my wife will be more willing to allow me to insure the car :)

Thank you in advance
 
To bad the people that looked at this post didn't know. Guess I'm going to wait for this weekend and search for my used one and do some testing.
 
Have you tried changing the DIS? The engine will usually run crappy when it is failing but it does also cause hard starting.
 
Have you tried changing the DIS? The engine will usually run crappy when it is failing but it does also cause hard starting.

Ahh yes, it's been replaced, a good known used one (from my '89 XR7) and a brand new one.
And before one says about the thermo-paste, yes it's on there :)
I've even did a relocation of the DIS module. Still had issues.
 

There is no codes at all, and the odd time it does start but idles around 450-550ish RPMS, I cAn leave it like that for a few minutes with an hint of black smoke out of the tail pipes. And still no codes, nor an CEL!!
At that kind of idle, if I give it a hint of throttle either by turning the butterfly or opening the idle air bypass screw it'll catch and run good. And yes the IAC has been replace, first a used one then a new one.
I have done some of the tests in the second link, and so far so good I may try to spend a day going through it abit better?
Also it's kind of hard to judge exactly when it's going to do it. It can act up after 5 minutes of sitting after being hot, sometimes longer. So it's a slow and painful process. Since once it starts and runs correct you can start and stop it over and over with no I'll effect. It NEEDS that sitting time.

I may try a used crank sensor (have one already) even thou a new aftermarket is only like $65

Thank you to the both of you
 
Seems like we are in the same boat brother. I am going to have to start running through that list from KMT's post.
 
Yah, this car is a pain in the ~~~.. i wish whatever is wrong with it would just completely fail, so then it'll be easier to figure out what it is causing this problem.

But least of Items i've tried

EEC-IV (used for an '91 Auto car)
Cam Sensor (1 used, and a New one, which is on it)
TPS (Used and New again)
IAC (Once again)
ECT (NEW, yah i'm opening the cooling system to install a USED one)
IAT (used)
DIS (used and New)

Resealed from the Heads to the Throttle body
Relocated the DIS module OFF the engine (even the new DIS module)
Tested as much of the wiring i could
Cleaned ALL connections from the 60 pin EEC connector to injector
Added a 4ga Ground from the battery to the engine and engine to the Chassis, and even Chassis back to the battery
OH and cleaned all the ground points for the Engine wiring.

So i may try and do the crank sensor, but do i really want to spend MORE money on this thing, when so far nothing is working.

Also my '89 now has a DIS module issue, but seems only to happen when the car has sat for like 3+ weeks. never has an issue when you start it every week:) HECK even drove it for like 180miles (300kms) and it never missed a beat :) But i do have another DIS module in the trunk JUST in case :p
 
Trouble starting during hot....

Is it like after you drive it for a while then shut it off and it wont start back up right away kind of thing? My friends car does that and he has to let it sit for 20 min. or so....the starter was the culprit!

Just sayin....

Tom
 
Unless the starter itself is causing some kind interference, i dought it could be it. The Car turns over very easily, you turn the key to `Start' and it turns over the same hot as it does cold.

And to add on to the information about this. I can drive the car to work (a whole 28 blocks or around 5-10 minutes, after work, 9.5 hours later, it'll still have issues starting. get home park it for the night for around 12-13hours, and it'll start no problems.
 
Have you tried cleaning the MAF sensor.....

Check your fuel pressure before and after the symptoms happen.....
 
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DieElectric compound between DIS and mounting surface?

Why yes sir.

Have you tried cleaning the MAF sensor.....
Check your fuel pressure before and after the symptoms happen.....

MAF sensor was cleaned, and even swapped out for a known good one.
Fuel Pressure has been checked and is good. even when it was having issues starting it was at a steady 40ish PSI the whole time it was cranking, and even shot up from around 20-25psi (after sitting nearly an hour) to 40ish psi instantly

And before the question(s) about leaky injectors or FPR, nope! both been check multiple times (injectors were also services and checked for flow, ect)

thank you again :)
 
This sounds very similar to a couple of problems I'm having right now.

Did you ever change the crank sensor, and if so what happened?

(I know...really old post but hoping he's still here)


Kevin
 
Crankshaft sensor

This sounds very similar to a couple of problems I'm having right now.

Did you ever change the crank sensor, and if so what happened?

(I know...really old post but hoping he's still here)


Kevin

Did you ever get a answer I think my crank sensor is bad
 
I know this is old and has been revived twice but the OP described my 91 titanium to the T.

Back before I did the 4r70w swap and the car was 100% bone stock I too had some very odd hot starting problems. One day when leaving work it started blowing billows of black smoke out the exhaust.

Turned out to be the ignition switch. There was a weak connection in there causing my ecu voltage to dip below 8v causing the o2s to dump fuel as well as the ecu from the injector offset.

A new ignition switch and 10 years later I hadnt a single problem with it ever again as of yet.
 
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