What are the specs and procedure for setting the base timing on a '91 3.1 V6 automatic? My Haynes manual says check the sticker. Of course the car doesn't have one. The local Pontiac dealer says use a 'dial back' timing light. On my 2.8 Camaro I used to disconnect the HEI connector and set the timing with the car in drive at 550 rpm. I don't know how many degrees BTDC or what rpm to use on this car.

TIA

 

May I suggest this?
How many miles on the car?
Lots?
Last time timing Chain switched?
I thought so.
Give the car a good tune up.
Then see how it goes with spunk & get up & go.
IF that helped, & ya want more, loosen distributor and just twist it one way or the other, by your hand, and tighten down.
You want the engine to purr, sound smooth.
Go for a short ride around the block, too.
Feel ok?
Tighten down.
BE SURE TO RESTART CAR, right away.
You so not want to much distributor advance. That make the car hard to restart.
DON'T twist more than a 1/2" and then try the short drive Test. You will feel more pep!
I did this with mine, when I swapped engines.
I just had it scooped.
I was off by 1/2 degree of proper 10 degrees (CA smog test checks timing).
I have a new timing chain on this engine, too.
IF you have an old chain and it's stretched, it will not make much difference to go to proper original timing mark. You have stretched the chain, to much for it to be "accurate" for the engine, in the current milage it is, now.

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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA

 

Eh, I disagree. If he's at 18 degrees advance, going back to the stock 10 will definately help. One thing you should check, too, is the balancer. Bring the #1 cyl up to TDC without using the timing mark. (I usually remove the spark-coil-to-distributor-wire, put a long phillips head screwdriver into the #1 plug hole, and turn the crankshaft clockwise with a breaker bar until the screwdriver stops rising.) Then, verify that the timing mark on the balancer lines up with the 0 degree mark of the timing indicator.

Oh and I think you know, but #1 cylinder for 2.8/3.1 V6's is the frontmost passenger one. Just about every other engine that GM's made uses the frontmost driver's side as #1... the 2.8/3.1 is different.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

OK, so is this right:

1. disconnect HEI connector.

2. run engine at 550 rpm in drive

3. set timing to 10 degrees BTDC

???

TIA

 

Try my way first!
I'll tell ya why.
Loosen the bot abck there and just twixt, slightly, one way or the other, but not to far.
IF that don't work,
DEFINETLY FOLLOW WHAT TOM SUGGESTS!
I just got my S-10 Blazer running.
I did the timing by ear, again.
Runs quite strong.
I have to drop the oil pan and swap oil pumps, now.
The oil pressure rises, then slowly goes down (40 down to zero).
I have two spares ones, rebuilding into one pump.
ONLY HOPE I do not have to raise the engine to drop pan & swap pumps!

Just try loosening & twisting ever so slighty.
IF ya don't like it, you've already loosened the distributor, anyway.


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Chat Soon,
KED85
Karl
1985 Firebird 2.8 to 3.4 swap project for Smog Happy LA, CA