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Bad crank position sensor - turned blown intake manifold
Posted: Wed Oct 12, 2016 6:25 pm
by mobil1
My dad's 2000 Bonne SE is sitting at the end of the driveway with a bad crank position sensor. It had the classic symptoms... sometimes it would crank but not start, randomly the tach would drop to 0 rpm and it has stalled a couple of times while driving. Right now it won't start at all. Cranks strong, just won't turn over.
I'd like to get the car over to my friend's garage. He's got a lift and a wealth of tools that I don't have. Is there anything I can do to get the car started at least once so I can drive it over there?
Re: Bad crank position sensor - any way to get the car start
Posted: Thu Oct 13, 2016 9:34 am
by harofreak00
Nope, you'll have to tow or replace in the driveway. I've done it before on the street, doesn't take too long if you know what you're doing.
Jack up the car, remove the wheel, remove the splash shield, remove the 24mm nut on the HB, use a HB puller to remove the HB, pry off the plastic shield, remove the 2 - 13mm studs on the CPS, remove CPS and reinstall in reverse.
Re: Bad crank position sensor - any way to get the car start
Posted: Mon Oct 17, 2016 11:04 pm
by ron350
Once the car won’t start when cold it is unlikely it will start again.
If you do manage to get it to start you wont get far.
Re: Bad crank position sensor - any way to get the car start
Posted: Sun Oct 23, 2016 11:43 am
by mobil1
OK... swapped out the crank sensor and ICM, and the car still won't start. I haven't tested the fuel pump yet, but I do smell gas after cranking. I did find that there is no spark at all 3 coils. Maybe a bad PCM?
Re: Bad crank position sensor - any way to get the car start
Posted: Mon Oct 24, 2016 9:05 am
by harofreak00
See anything wrong with the wiring harness? How about a bad ground on the block under the coils?
Re: Bad crank position sensor - any way to get the car start
Posted: Mon Oct 24, 2016 6:49 pm
by MKMike
How about a blown fuse?
Our cars have fuses that control some critical things.
For instance underhood fuse#15 is the DIS fuse and fuse #19 is for the PCM Ignition circuit
Re: Bad crank position sensor - any way to get the car start
Posted: Sat Oct 29, 2016 2:09 pm
by mobil1
So I tried starting the car again... and BOOM! Last thing I did after replacing the crank sensor was check all the fuses. Correct my ignorance, but I'm thinking there was a lot of fuel in there and when it finally had spark it just backfired?

Re: Bad crank position sensor - any way to get the car start
Posted: Mon Oct 31, 2016 9:28 am
by harofreak00
That is usually a sign of a bad fuel pressure regulator, but with how much you were cranking on it, yes you probably filled it with fuel. At least it has spark now! Replace the manifold and you should be good.
Re: Bad crank position sensor - any way to get the car start
Posted: Mon Oct 31, 2016 10:37 am
by mobil1
harofreak00 wrote:That is usually a sign of a bad fuel pressure regulator, but with how much you were cranking on it, yes you probably filled it with fuel. At least it has spark now! Replace the manifold and you should be good.
What other possible engine damage could there have been from this?
Re: Bad crank position sensor - any way to get the car start
Posted: Mon Oct 31, 2016 11:11 am
by harofreak00
You got pretty lucky, usually when this happens the engine starts on fire. If you don't have any fire damage, just replace the manifold.
Re: Bad crank position sensor - any way to get the car start
Posted: Sun Nov 06, 2016 7:07 am
by Kevin Amstutz1
Sometimes a bad CPS will take out the ignition module. Ignition modules don't like a bad CPS.
Re: Bad crank position sensor - any way to get the car start
Posted: Sun Nov 06, 2016 10:52 pm
by RJolly87
Which is odd, because the computer fuels based on the CPS.
Glad it didn't catch fire on you. I had something like that on my mom's blazer, only the firing order was wrong on the distributor. It exploded in the exhaust, and blew the muffler apart.
Re: Bad crank position sensor - any way to get the car start
Posted: Sun Nov 13, 2016 4:53 pm
by mobil1
Finally took the time to remove what was left of the old intake manifold. As you can see, it's in multiple pieces. I did my best to vacuum up any of the small pieces of the intake and surrounding dirt/debris.
What else should we do before installing the new intake plenum? Do we need to do a coolant flush and oil change? Are the plugs still good (we just changed them in early summer)? I'm thinking we might do the lower gasket since we already have it taken apart...

Re: Bad crank position sensor - turned blown intake manifold
Posted: Sun Nov 13, 2016 5:11 pm
by 96 SSEi
hi, since your intake blew, change the fuel pressure regulator, and oil change for good measure.
Re: Bad crank position sensor - turned blown intake manifold
Posted: Sun Nov 13, 2016 5:26 pm
by redfury
I'd do the lower intake gasket since you are already that far into it and obviously not in that big of a rush to use the car. Take the time, do the preventative maintenance and have the piece of mind that comes with it. Get some new coolant elbows, a good set of Felpro gaskets, flush out all that old Dexcool ( don't forget the heater core ) and think about doing the valve cover gaskets too since this will be the easiest time to do them.
Hardest part of doing the intake manifold for me was simply cleaning it up and cleaning out as much carbon as I could out of the ports in the heads. Buy a case of carb cleaner and hose her down.
Re: Bad crank position sensor - turned blown intake manifold
Posted: Sun Nov 13, 2016 5:36 pm
by RJolly87
Also, if you do address the LIM gaskets, it may be worth the trouble to address any casting imperfections that the Series 2 is known for (Or even a full on porting).
Re: Bad crank position sensor - turned blown intake manifold
Posted: Tue Nov 15, 2016 3:02 pm
by redzmonte
Lower intake gaskets (Aluminum version not plastic) and Aluminum coolant elbows, along with some fresh injector O rings and a FPR. Got to drain the Coolant a little so might as well drain and refill that cooling system. If valve cover gaskets are leaking, I would do them, front is cake, rear is easer with the intake off.. Might also clean throttle body blade and IAC valve.
And personally I would do a little cleaning while in there, clean the intake manifold when out and clean up the injector holes... I hate working on dirty engines, makes me feel happy when all done and everything is clean as a whistle... Might do a Top engine clean every 30K from now on. looks gunky in there.