Does anyone have a picture of a power stage or ignition amplifier for a 240(1991)and where it is located? I am clueless and would like to know what I am looking for at the bone yard. Also, are they difficult to remove and install and do they go bad often? Stalled in the left lane is a dangerous place to be. Thanks.

If you are not POSITIVE that is the prob check your fuel pressure regulator. Often same sypmtoms. Pull vac hose from manifold leaving the other end attached to the reg and if you can smell or taste gas it is bad.

I pulled the vac hose from the manifold/rail and gasoline flowed pretty heavy from the hose, does that mean that the fuel pressure regulator is bad? Thanks.

Hi!.just replaced mine after 220K....to fix a no warm start problem.....also replaced the crank position sensor at the same time.....problem went away...sloppy troublshooting but had to get on the road.......bought a bosch replacement unit...$70 at eeuroparts or fcp......came with a little tube of thermal transfer grease....as mentioned before, clean the old stuff off the heat sink and apply the new stuff.......j.

Is the crank position sensor a difficult replacement project and where is it located? Maybe I will replace it along with the power stage as you did. Thanks.

Hi!.well, the mystic of Mystic pretty much summed it up,.....but fwiw i just read the faq and went at it.yes, it's a bit of a pita.......did it by myself, but a flashlight holder would have lowered the stress level....damned inconvenient place to work.....perhaps , a somewhat bizarre approach to this, but i got an old piece of carpet and laid it over the engine and got on so that i could reach both hands around the back of the block....careful not to put any weight on the fpr and stuff.....must have been quite the sight....10mm bolt came out easy enough....faq contains many warnings, so went slow but had no probs......mostly working by sense of touch.....did this on a 100f day in CT
in early aug....made that first beer taste real good............j.

Crank position sensor is used on '89 and later 240s.

Located at back of block, below the cutout edge of the firewall.
Location makes changing it a PITA. My regular mechanic swears it's not a problem but has done it dozens of times if not more.
I never replaced one myself.

Get a flashlight.
Stand at passenger side fender (exhaust side).
Look in at rear of block where it disappears under edge of firewall.
See single electrical cable going down onto block, about 1/4 inch diameter.
Cable goes to crank position sensor.
If cable looks messed up then you definitely need a new one.
Cable is shielded like TV coax, if the shielding gets compromised the computer doesn't get a proper signal.

See FAQ section on engine electrical sensors or something like that, I'm pretty sure it's in the FAQ.

I think access might be easier for standard tranny due to size of tranny.
My friend with 5-spd reached it from underside of car but still had a bit of a rough time.

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DAMHIK: Don't Ask Me How I Know - - - Sven: '89 245, IPD sways, electric rad. fan conversion, e-codes, 28+ mpg - auto tranny. 500 mi/week commute. '89 245 #2 (wifemobile). '90 244 (spare, runs).

I was told that they are very susceptible to distortion caused by corrosion between the unit itself and the heat sink. The surfaces should be clean, and then protected with special heat-conducting electrical grease - not sure what it is called.

Thanks for the advice.

On your 91, stand in front of the grille and peer across the top of your battery at the left fender. You'll see a 1" x 2" rectangle of gray plastic. Remove the whole thing, heat sink and all. Clean the plug contacts or wiggle the cable to it while it is running to see if there's a poor connection there.

Look like this:

http://fcpgroton.com/images/3501921.jpg

They're nestled to in the front driver's side corner of the engine compartment.

They do indeed go bad.

-Ryan

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Athens, Ohio -- 1990 245, 128k, M47, E-codes -- 1991 745, 278k (girlfriend-mobile)