1997 gmc yukon - top of distributor

[GEARJAMMER1986]

Hello fellow forumers, lol. I just bought a 1997 yukon 4x4 . And i bought tune up parts and i went to take the old distributor cap off only to realize, that the top of the distributor (where the cap is), that i can twist it, And when i do, it runs a lil rougher or smoothes out. How do i adjust it to where it needs to be? and, also tighten it? I do not know exactly where it should be for optimum smooth idle. Any help is greatly appreciated.

 

[retorq]

Check to see if the hold down is loose. You would need a scanner of some sort to fix that properly.

 

[BRUTUS_T_HOG]

Sounds like the hold down bolt is missing... is this a round cap or a flat cap? The flat cap distributors are supposed to bolt on in one spot and can't be adjusted without modification.

The round cap distributors are adjusted by disconnecting the tan/black EST wire located under the glovebox or near the distributor on the firewall and using a timing light adjust the timing to 10*BTDC

 

[retorq]

First the Vortecs have the "flat" corrected cap, second, you adjust timing to 0 not 10.

 

[BRUTUS_T_HOG]

First the Vortecs have the "flat" corrected cap, second, you adjust timing to 0 not 10.

You are correct, 0* is the correct timing adjustment for the round cap. Guess I was thinking of Ford.

My GM service information is showing that a 97 Yukon uses a flat cap, which is not normally adjustable. And even when you mod them to be adjusted it doesn't change ignition timing it changes fuel injection timing

 

[retorq]

I think all Vortecs from the factory use the flat cap. When I did the Vortec swap on my Camaro and later my Tahoe I used the distributors from those vehicles with the "std" caps. I never liked the looks of those corrected caps much ...

 

[BRUTUS_T_HOG]

I think all Vortecs from the factory use the flat cap. When I did the Vortec swap on my Camaro and later my Tahoe I used the distributors from those vehicles with the "std" caps. I never liked the looks of those corrected caps much ...

Yeah I hate the flat caps, they short out internally and crossfire. Some i've even seen prevent the engine from starting cause it crossfires so bad

 

[SunlitComet]

Second actually you set the cam offset or CAM_RETARD to zero not the timing on a vortec. timing is controlled within the pcm.

 

[GEARJAMMER1986]

Hi guys! Thanks for all the help, I have one more issue im dealing with. And its starting the yukon. When its cold, And i go to start it, it fires right up. After its warm, Sometimes it takes me three tries to start it and it has long cranking time, then when it starts, it sputters, then picks up to normal idle speed. Ive already replaced air filter, fuel filter, spark plugs and wires, cap and rotor. Any idea what causes this?

 

[willxfs]

Its been several years but my 1998 Tahoe had the same symptoms you describe. It ended up being the fuel pressure regulator leaking. If the fuel injection "spider" assembly hasn't been changed and it's still the old style, now may be a good time to change that out. A new fuel injector assembly will come with a new fuel pressure regulator.