97 S-10 question

[krue]

I'm trying to get my dad's 4.3l running right since my brother replaced the intake gaskets. We indexed all the timing marks on the dizzy but it still doesn't idle as smooth as it did before he parked it. We do have one vacuum leak to fix, so I know that isn't helping. Currently with it running and using my timing light where should the mark be in relation to the timing tab be? Right now the mark is about an inch clockwise of the tab when the light fires.

[gchemist]

If it's timed to TDC, the computer is retarding the timing. It's too late now, but as long at motor is not cranked, the distributor can be dropped back in without problems. I marked mine and installed back the same way. Cranked right up.

Fix the vacuum leak or you'll be chasing unnecessary problems. The leak may solve your problem.

[krue]

Ok we fixed the vacuum leak. Sounds better but timing light shows no change.

[Z16]

If it's a 97, that's OBD2, and the timing is controlled by the computer, and a timing light doesn't really help. As long as the distributor is within a couple degrees of where it should be, the computer does the rest. And the computer can change the timing so quickly and frequently that setting the timing with a light can be confusing. Is your check engine light on? The timing is set with either a scan tool, or can be set with the check engine light, if there are no other codes. Just turn the distributor until the light goes out. I've seen Vortecs idle anywhere from 6-18 degrees at idle, depending on what the computer wants

[GMCJOE]

Best bet is to grab you a shop manual and drop the distributor in how the manual says. Beware though, one of them the picture is rotated upside down. I can't remember if it was a Chilton's or Hayes manual when I help my buddy rebuild his 97 blazer 4.3. We initially dropped his in the way the picture and directions showed, didn't want to run but fired up once running like total @$$. I looked at the picture a little closer and noticed the position of the block, flip the book and seen what was wrong. Dropped it in right, started up and ran like a champ.

Basically, I believe you are a couple teeth off on your drop of the distributor, the computer will try to adjust the timing to let it run if it can. Get a manual, look it up. It will save you some time and hassle, and very helpful when trouble shooting additional problems that come up later down the road.