Crank sensor

[creepin_olds]

hey guys,

 

Just a quick question. I have a 90 GP with 3.1 MPFI. Started jerking on me really bad coming down the road and then just turned off. After letting it sit for a little while it would start back up for about 2-3 minutes and then turn back off. Was able to get it to the shop and found out it was not getting any fire to the engine. So my mechanic started to replace the crank sensor, and the damn thing broke. he said the one in it is so old and brittle, it broke off trying to take it out and now he is going to have to drop the oil pan andshit and everything just in order to get the old one out. Does that sound right to you or does it sound like he is trying to just get more more out of me? You know what I mean? Let me know what you guys think. And also what the hell does the crank sensor do? and if it does go out can it make your car not get spark anymore?

[White93z34]

http://www.w-body.com/forum/viewtopic.php?t=33380

[jeremy]

http://www.w-body.com/forum/viewtopic.php?t=33380

 

[5speedz34]

hey Was able to get it to the shop and found out it was not getting any fire to the engine.

 

The crank sensor reads where the engine is during its 4 strokes. It tells the ecm when to send spark to the engine. So yes you need it. The engine will not get "fire" without it.

[creepin_olds]

so if it does go out, then it can fuck u up big times and what do u mean by its four strokes?

[GP1138]

so if it does go out, then it can fuck u up big times and what do u mean by its four strokes?

 

Your engine is a four-stroke engine, Intake, Compression, Power and Exhaust. The camshaft is at different positions as this is happening. The CPS sees this when the crank is turning, and tells the spark plugs when to fire according to where the crankshaft is.

 

Therefore, if you have no CPS or CPS signal, you won't have a running engine.

[5speedz34]

Thanks jon, I couldn't think of a better way to explain it.

[creepin_olds]

Thanks for all the help guys. How much do u think is a fair price to pay to get this fixed? considering that he is going to drop the oil pan and everything?

[creepin_olds]

Does anyone here have any ideas whatsoever?

[5speedz34]

Why have him drop the pan, when you could do it yourself, or tell him how we do it.

 

FWIW: The cradle needs to dropped to get the pan out.

[DaveFromColorado]

the crank possition sensor only reads the crankshaft angle - not which stroke it's on - as it can't tell the difference between TDC on the compression stroke, and TDC on the Exhaust stroke. This is where a Camshaft sensor would come in, because using the two sensors, it'd be able to determine which stroke it's on, and where the crank is - but because of the waste spark ignition system, and the bank firing of the injectors, it doesn't really care what stroke it's on.

 

Either way, if the mechanic broke the sensor in the engine, then it's up to the mechanic to fix it at his expense, as pulling the oil pan was not part of the original estimate, and legally they can't charge ya more then 10% over what the original estimate was.

 

Make 'em fix it, at their cost, not yours. You didn't brake the sensor, the tech did.

 

--Dave.

[joey b]

sounds kinda harsh. When tryin to remove the CPS on my engine it broke and fell into the oil pan. Course the engine was trashed and out of the car already. My CPS had broken and was hanging at an angle inside of the engine block, probably just as yours was.

[Dark Ride]

My mechanic fixed it by dropping the oil pan( that was two years ago, had I known what I know now i would have done it myself)

 

As another alternative, my car did exactly what yours is doing. Running for a little bit then dying, if I left it sit for a little bit it would start then die again. It turned out to be my Coolant Temp sensor of all things, It was shot and kept telling the ECM that it was overheating. It finally gave me a code 14 (i think) after about a week of doing this. Might be worth trying, its much cheaper and easier to replace then Crank sensor. Too bad he already broke it off. I'd Make him fix it, You didn't break it, he did.

 

Mitch

[Lee]

Okay, I'll answer your question. I've had my crankshaft sensor replaced 2 times. In 1998 it costed me $136. It was done in Oshkosh WI; a college city of 68,000 people. In 2001 I had it done at a cost of $100; in a small country town of 1400 people.

 

Cost for dropping the pan not included. Mine never shattered though I've heard they do sometimes.

 

so $100 to $136

 

The sensor alone runs mid $20's or less.

[CSupremeLover]

Ah yes he is telling the truth. I was just trying to dislodge one today. they are PITA's (pain in the a**es). Mine is on the rear block. They get carboned up and are almost impossible to get out. They CAN be removed but....ya gotta be careful. Did he Dx to KNOW that was the problem?

[Toxie]

i had to drop the pan to get mine out, took me most of a day but i got it done and it ran great after that. mine broke off and i could not get it out. it pushed into the block and dropped into the pan. major PITA... if you feel comfortable with it you can do it yourself, it just takes time and lots of cool beverages...