Auxiliary fan - purpose.

[thegawd]

The problem with these distributors is there are vents on the bottom, in the aluminum base. These vents originally have a screen in it that gets clogged and once its clogged it cant breath so condensation builds which creates corrosion on the contacts. Corrosion prevents an electrical connection and electricity will always take the easiest path so it mis fires. These vents are prone to clogging up but I did not have any vents in the oem base (at least I think it is original) I found out there was a manufacturing defect but gm used them anyways. I drilled 2, 1/8" holes where they were supposed to be. This was about 5 years ago or more, the burb got a complete acdelco tune up all around which made it incredibly more fuel efficient. Lately I'm thinking that original base is done and I finally bought a new more improved complete dist. It's not delco and so I might but a new delco cap... I cant remember what brand off the top of my head but there are absolutely no complaints in the reviews.

So as long as the distributor can breath there wont be any problems with the spark taking the correct path and not misfiring. I didnt think I had a problem with my dist because I was getting spark, yup it just wasnt firing in the correct order.

Al

 

[Pinger]

Any tips on re-installing the dizzy after removal for inlet manifold replacement? It seems to be the trickiest aspect of the whole job.

 

[thegawd]

No sorry Not from me as I haven't done it yet. I have only changed the cap, rotor, plugs n wires ect. I'm about to change the entire distributor.

Al

 

[HotWheelsBurban]

I think the biggest issue is getting it back in exactly where it came out,in relation to the drive gear/ camshaft gear meshing correctly. If you're a tooth off it will sorta run but more than that and it won't. Too many horror stories on here about people doing this and what they had to have done to fix it. Other than that, I could probably handle the job (there's a good thread on the engine section on doing this job, from a member called Ginger). But it's a bit more involved than I want to tackle in my driveway....

 

[east302]

Any tips on re-installing the dizzy after removal for inlet manifold replacement? It seems to be the trickiest aspect of the whole job.

It’s not hard to get it lined up. Before removal, mark the distributor relative to the intake and the rotor relative to the distributor housing. Here’s the procedure:

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Use a flathead screwdriver to align the oil pump shaft, you’ll know when it is lined up when dropping the distributor down.

A scanner is used to set the CMP offset, search here for “CMP retard” and you’ll see some options.

 

[df2x4]

One thing about this forum I struggle with is that I spot something on a thread and mean to come back to it and can never find it again! Eg, there is a current thread with a photo of the group of fuel injectors (spider?) as they sit on the manifold - any idea which thread that was? (Don't go searching but if you remember off the top of your head...)

Just a quick tip for stuff like this... Google's search indexing is sometimes far more helpful than the one on this site. For example, if you go to Google and type (without the quotes) "site:gmt400.com spider injectors" then Google will give you every post and image from this site where spider injectors are mentioned.

You may already know this Google trick as it's been around for a long time, but it can be extremely helpful.

 

[98chevy2500SS]

^x2, I always use Google when searching for threads on this forum. I rarely use the site's own search box, because it seems like you have to be ultra specific when finding threads.

 

[thegawd]

Cheers to you both for those helpful tips on searching the site and the dizzy procedure.

Nice!

Al

 

[HotWheelsBurban]

I can see the need for the hole now you mention it.

Mine has the spare indoors and what I thought was a 42USG tank. Just checked my build sheet and no mention of it but on another printed sheet it says 42USG. But that sheet looks like a spec sheet printed from the internet (external dimensions etc).

The hole is for the spare tire lift, like was mentioned. The GMT400 series uses the same rear bumper for pickups (which have the spare tire underneath the bed) and the Tahoe/Yukon/Suburban, which have it inside the cargo area, mounted to the left side behind the wheel well. The factory jack for changing tires etc. is located in the trim on the left side, ahead of the wheel well. The top of the box where the cupholder is for the 3rd seat passengers lifts off, and the jack components are supposed to be in the compartment inside. You've probably figured this out by now, but I was re reading some posts and thought it bore mentioning

 

[thegawd]

On my burb I ran the 4 way trailer connection through this hole, on my burb what else could it be for? I realized what it actually was on my sierra when i finally got it.off my buddy. Hey my buddy rebuilt the spare tire hoist, I was incredibly surprised that the spare tire very easily was removed. Blew my mind as every other time I tried to help someone get the spare tire down that they have never used.... well the cable always got cut. The spare tire and its hoist needs to be maintained or it wont help you at all when you need it.

Al