88 Suburban TBI Smog pump question

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bucket

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My 90 burb has had the smog pump removed by previous owner. He put headers and aftermarket cat on it. I will have to look and see where the vacuum advance is hooked up. it runs great but it does surge a little at idle. Idles fine until its warmed up and then it will idle around 700 rpm for 10 seconds or so and jump up to 950 for about the same time and only does this in park. :shrug:

A '90 wouldn't have a smog pump to begin with, it doesn't have a vacuum advance either. Vacuum advance was only on carbed trucks.
 

Derick C.

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A '90 wouldn't have a smog pump to begin with, it doesn't have a vacuum advance either. Vacuum advance was only on carbed trucks.


It had one.. I have it in a box with the stock exhaust manifolds. :shrug:
 

bucket

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It had one.. I have it in a box with the stock exhaust manifolds. :shrug:

Was it from California maybe? I had a bone-stock '90 and it didn't ever come with one. Or maybe it's because it was 3/4 ton. For some reason I was remembering the '89 and up model years not having one.
 

Derick C.

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Was it from California maybe? I had a bone-stock '90 and it didn't ever come with one. Or maybe it's because it was 3/4 ton. For some reason I was remembering the '89 and up model years not having one.


Possibly but not real sure. :shrug: The guy I got it from took it over when his brother passed away who was the 2nd owner. The only things he knew for sure was what he could find in all the paper work his brother had for it.
 

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Do you still have the stock air cleaner housing with the emissions sticker?
 

skysurfer

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No, even though mine is a Cali truck I don't have an air injection pump because of the 8600 GVWR. I think the 1/2 tons had to have them, seems like back when I was doing smog tests the half-tons always had more emissions equipment than the three-quarter ton rigs.
 

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