1991 2.8 v6 trooper timing

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1991 2.8 v6 trooper timing

Postby swiftrev » Tue Apr 24, 2007 9:33 pm

I had a leak at the rear so I removed the distributor to add an O ring, but I didnt mark rotor position correctly. as I went to set TDC at crankshaft I see the damping pulley has 3 different marks.
which one is the timing mark and how can I find top dead center at compression without taking off the valve cover?

I turned the engine over after I first installed distributor with no luck
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Postby LTC Don » Wed Apr 25, 2007 12:19 am

IIRC, the pulley has three grooves cut into it, but only one has white paint in it.

Not sure about the rest of your situation.
HTH


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Postby Ed Mc. » Wed Apr 25, 2007 12:26 am

Typically there will be one deep, wide groove across the outer diameter of the harmonic balancer and that's the timing mark.

One way to figure out what's what is to pull all the spark plugs except #1 (pssgr's side, front plug). Then, rotate until you feel compression. As you get to TDC, compression will peak then slack off, at that point the timing mark will be pointing to Zero on the timing scale. I marked mine with white paint to help it stand out.

From there, position the distributor such that the rotor is pointing to around the 7-o'clock position as you're facing to the rear of the vehicle. Whatever contact in the cap the rotor's pointing to at this point becomes #1 cylinder.

If the rotor is not in the 7-o'clock position, either remove the distributor and reorient the rotor, or leave as is and wherever the rotor points becomes #1 and you follow around the cap with the other plug wires.

Firing order is 1-2-3-4-5-6, clockwise, around the distributor.

1-3-5 on the pssgr side, 2-4-6 on the driver's side.

Don't forget to unplug the inline connector on the ESC (Electronic Spark Control) wire when you adjust timing, not possible to accurately set the advance without unplugging this wire. This wire is the only one in the center console (check under the front tray of the console first) with an inline connector and is usually white with black stripe.

You'll find if you set advance at around 13 deg BTDC she'll run a bit peppier.

HTH & G'luck.........ed
'90 3.4 Troop LS;
'89 Troop RS (Exhaust Valve Challenged), now gone to a Good Home!
Yes, I am a Trooper-Holic!!!
Keep On Troopin' !
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Postby swiftrev » Fri Apr 27, 2007 9:37 am

I found the timing mark, LOL the white paint is long gone.

ahh, since my distributor was in the same correct place I just rotated the plug wires and It at least started... and ran very rough.

so to reset timing do I unplug the ecm wire before starting it or after, and have I done any damage to it, starting it with rough timing?
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Postby swiftrev » Fri Apr 27, 2007 8:05 pm

hey thanks for the info
I just twisted the distributor till it sounded better.
and the distributor WAS the source of the leak....thought I would have to take off the intake manifold and BREAK something else!
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Postby Ed Mc. » Fri Apr 27, 2007 9:13 pm

Glad you got 'er going again. However, with the Electronic Spark Control, it's real hard to get an accurate timing setting by ear.

You'll probably find that if you unplug the ESC wire and slap a timing lite on #1 cyl you'll be able to properly adjust advance, and it'll run so much better.

Seriously doubt you did any damage, usually if the timing is off she just won't run. One exception is if you were to get it so messed up that it backfired thru the TBI. This can blow out the MAP (Manifold Absolute Pressure) sensor so if you get any strange "check engine" lites or other poor running symptoms it's something to check.

If you had no backfiring, not to worry, just readjust timing and enjoy!
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