Bad Crank Sensor?

[phillabaum03]

Hi guys, my car died on me a month ago and I have been trying everything since, I found out im NOT getting pulse to cylinders 3 and 4 but AM to 1 and 2 which is odd, and no mechanics seem to know why. They say anytime they have a problem like this its all or nothing. I've tried 2 other ecus, a new cam sensor, got 12 volts all the way up to the injector clips, wires all seem ok, really the only thing I can think of that I have NOT checked is a crank sensor. But would a bad crank sensor have anything to do with injector pulse, I thought crank sensors only controlled spark. PLease help guys, thanks. Oh and this is on a (95 gst)

 

[shuedaman]

Try swapping the working injectors with the non-working ones, this will prove your injectors are working/not working.

How was the car running before the problem? Did it just not start one day or die while running?

 

[TjPhillips36]

Crank sensors control spark and fuel injector pulse. If it's bad then you will see no spark or fuel injector pulse on any cylinder at least in my experience. Try the MPI Relay...

http://www.dsmtuners.com/forums/problem-diagnosis/263224-mfi-mpi-relay.html

Are you getting spark in every cylinder?

 

[phillabaum03]

Try swapping the working injectors with the non-working ones, this will prove your injectors are working/not working.

How was the car running before the problem? Did it just not start one day or die while running?

I actually put evo injectors in since I was having the probelm and those injectors work. The car ran fine. Just drove 9 hours home from NC the day before with no problems then the next day I made a normal right turn and sputter sputter off. Wasnt even beating on it.

 

[phillabaum03]

Crank sensors control spark and fuel injector pulse. If it's bad then you will see no spark or fuel injector pulse on any cylinder at least in my experience. Try the MPI Relay...

http://www.dsmtuners.com/forums/problem-diagnosis/263224-mfi-mpi-relay.html

Are you getting spark in every cylinder?

i didnt know they controlled both, im gonna borrow one and try it. Might as well. I did borrow a buddies mpi relay and still same thing. The relay just is the "fuse" pretty much right? I do have power to those injectors but its not getting the ground in order to pulse. Only to those 2 cylinders. So odd, but i miss my car!!

 

[Timechg]

Have you checked your power transistor unit (AKA ignition control module). That would cause it not to spark on all cylinders as well.

 

[phillabaum03]

Have you checked your power transistor unit (AKA ignition control module). That would cause it not to spark on all cylinders as well.

i said it DOES spark! re read man

 

[shuedaman]

Are you saying that it works with Evo injectors and not the 1000cc ones you were previously running, or that it died with the Evo injectors installed?

Still learning about ECU's, but if the stock ECU works like megasquirt then it fires the injectors by grounding them out. Have you THOROUGHLY checked the ground wires to those two connectors? Just a thought, as I've had to check wires many times only to find more problems, even with some stock stuff. As stated by TjPhillips36, the crank sensor does control fuel delivery, so that could be your problem. There is a check you can perform per the manual to see if this sensor is working properly, and you can also check the cam sensor.

 

[BoostedTalonTS]

Odd that you will have injector pulses to two out of 4 injectors... Probably not the CAS (that's generally all or nothin).... You also tried replacing the ECU & injectors themselves..........

Sounds to me like the injector resistor pack man... Try it:
x1 plug and x2 10mm bolts & yer done.

 

[phillabaum03]

Odd that you will have injector pulses to two out of 4 injectors... Probably not the CAS (that's generally all or nothin).... You also tried replacing the ECU & injectors themselves..........

Sounds to me like the injector resistor pack man... Try it:
x1 plug and x2 10mm bolts & yer done.

i know man, it is weird, even the mechanics i've talked to say the same. I tried a resistor pack and even that didnt work. This has been the hardest problem with cars i've ever had man. Im gonna try this new crank sensor and i'll try another resistor pack, but besides that idk. all the wires seem to be fine. But when I check the wires right off the ECU they dont even pulse, like the computers bad.. Since my car came stock with an EPROM i cant get ahold of one to try, but I tried 2 NON eprom, but wouldnt they work fine?

 

[BoostedTalonTS]

At that point, have you tried performing a continuity test between the injector clips and at the ECU? -I suspect that there might be either a short between #3 & #4 injector wires or they might even be completely open from the ECU location to the injector clips on at least 2 wires.

Only one way to find out...

Break out the multi-meter and start with the ECU & all injectors completely disconnected and start measuring for continuity (from each end) on each wire. If they all check out, then try testing for continuity between the different wires to see if they aren't shorted together.


Interestingly enough, I have encountered a similar problem on a 2G before... Turns out that it was in a wreck and the body shop ended up replacing the front clip... A 'Buzz saw' (circular grinder) was used to remove the old, damaged front clip... Accidentally, the body shop guy ended up hacking through much of the harness that parallels part of the firewall that was removed. -The idiot never noticed (or never admitted it)...

It then comes into my shop and I get the first stab at it. -The car barely ran, multiple, inconsistent misfires... Scratching my head, I ended up performing a continuity test on each of the injector wires... Most measured continuity! -Unfortunately, most of them ALL measured continuity not only from point to point, but from wire to wire as well... I spend the next few hours finding/repairing multiple shredded/exposed wires in about a 6-7" section of the main wire harness that runs just behind the carpet, along the floor pan, passenger side, from the ECU. -It was quite the learning experience... Although my patch work fixed the issue, I recommended that the body shop own up to damaging the main harness and have it replaced...

Needless to say, the car was picked up by the owner the next day who was none-the-wiser. -I'm just glad that it wasn't an 'on-the-books' job for my shop, as it was the neighboring body shop that F'ed it up and they were looking to have us (ME) bail them out as a 'favor'. -That was the last time I did that body shop any 'favors'.

-Hope this helps

 

[phillabaum03]

At that point, have you tried performing a continuity test between the injector clips and at the ECU? -I suspect that there might be either a short between #3 & #4 injector wires or they might even be completely open from the ECU location to the injector clips on at least 2 wires.

Only one way to find out...

Break out the multi-meter and start with the ECU & all injectors completely disconnected and start measuring for continuity (from each end) on each wire. If they all check out, then try testing for continuity between the different wires to see if they aren't shorted together.


Interestingly enough, I have encountered a similar problem on a 2G before... Turns out that it was in a wreck and the body shop ended up replacing the front clip... A 'Buzz saw' (circular grinder) was used to remove the old, damaged front clip... Accidentally, the body shop guy ended up hacking through much of the harness that parallels part of the firewall that was removed. -The idiot never noticed (or never admitted it)...

It then comes into my shop and I get the first stab at it. -The car barely ran, multiple, inconsistent misfires... Scratching my head, I ended up performing a continuity test on each of the injector wires... Most measured continuity! -Unfortunately, most of them ALL measured continuity not only from point to point, but from wire to wire as well... I spend the next few hours finding/repairing multiple shredded/exposed wires in about a 6-7" section of the main wire harness that runs just behind the carpet, along the floor pan, passenger side, from the ECU. -It was quite the learning experience... Although my patch work fixed the issue, I recommended that the body shop own up to damaging the main harness and have it replaced...

Needless to say, the car was picked up by the owner the next day who was none-the-wiser. -I'm just glad that it wasn't an 'on-the-books' job for my shop, as it was the neighboring body shop that F'ed it up and they were looking to have us (ME) bail them out as a ‘favor’. -That was the last time I did that body shop any ‘favors’.

-Hope this helps

i did check to make sure the wires from the clip to the ecu were getting power and they are. How would I check to make sure for some reason their not grounded to eachother? I had an electrical problems only place glance at it until they were stumped theirselves and said for me to try a wiring harness that it might be alot of work and money for them. I took that as if a place that specialed in that stuff turned work/money down then it must be something. But it seems like a bad ecu but like i've said, i've tried 2 others, but neither were EPROM, does that matter?
Im really getting fed up with it, anyone live in PA? Wanna come get this . I was hoping it was a cam sensor so I did ALL kinds of BS work to get it in and then still nothing, so im gonna try a new resistor box and crank sensor tomorrow. Maybe i'll get lucky. I lose my license the 2nd of july, i just wanna drive this car a little before I do. GRR!!

 

[bobby180360]

Crank sensors control spark and fuel injector pulse. If it's bad then you will see no spark or fuel injector pulse on any cylinder at least in my experience. Try the MPI Relay...

http://www.dsmtuners.com/forums/problem-diagnosis/263224-mfi-mpi-relay.html

Are you getting spark in every cylinder?

In my experience with it, the crack sensor only controls spark. My car's crank sensor went out, it took a while to figure it out, but every time i would try to start my car it would foul out the plugs so it must only cut the spark. IF I'M WRONG could some one sent me a pm explaining, cause I like learning about our cars.

 

[BoostedTalonTS]

i did check to make sure the wires from the clip to the ecu were getting power and they are. How would I check to make sure for some reason their not grounded to eachother? I had an electrical problems only place glance at it until they were stumped theirselves and said for me to try a wiring harness that it might be alot of work and money for them. I took that as if a place that specialed in that stuff turned work/money down then it must be something. But it seems like a bad ecu but like i've said, i've tried 2 others, but neither were EPROM, does that matter?
Im really getting fed up with it, anyone live in PA? Wanna come get this . I was hoping it was a cam sensor so I did ALL kinds of BS work to get it in and then still nothing, so im gonna try a new resistor box and crank sensor tomorrow. Maybe i'll get lucky. I lose my license the 2nd of july, i just wanna drive this car a little before I do. GRR!!

Like I said earlier...

Break out the multi-meter and start with the ECU & all injectors completely disconnected and start measuring for continuity (from each end) on each wire. If they all check out, then try testing for continuity between the different wires to see if they aren't shorted together.

I take it that you do own (and know how to use) a multi-meter, right? DSMers & other car enthusiasts alike: a multi-meter SHOULD be considered a standard issue tool.

 

[bobby180360]

...wouldn't a stock ecu run it, but not really how it should be? And if the wires are grounded out against each other they would have to be bare wire touching each other right? How far did you go into the harness, did you search for some broke wires or are you more of a take some where kind of guy. Electrical problems are not fun and very time consuming you NEED a lot of patience too. good luck let us know

 

[phillabaum03]

I do know how and own a DVOM.

bobby180360<---your like replying and asking ?'s man. Dont reply unless your a little more sure what your talking about. And I do everything myself unless it gets me stumped as well as friends, my instructors at wyo-tech, and mechanics then its out of my league as you say. Still havent found any luck...

 

[phillabaum03]

so I put the crank sensor in, and the car ran. Took it for a victory lap around the neighbor hood, took a right hand turn the the fugger dies like it did the first time. I think I'm wiping these crank sensors out, which could only mean one thing...CRANK FUGGIN WALK

 

[TjPhillips36]

Well you can check the endplay in the crank and see if it is within spec.

 

[phillabaum03]

instead of putting a new crank sensor in, I put a 1g CAS in instead so it bypasses the crank sensor. So now I dont have to worry about it wiping out 1984398 crank sensors, and now I guess just wait until it blows. I'll try not to hold the clutch in on a right turn . After like a month and a half it finally runs! yay