Super Crapy Milage.......

[sub006]

Contact Van Gordon and Brown in Claremont, California. They have a Clayton dyno and all the latest GM software. Scott Brown will trace, find and correct any problem(s) affecting your vehicle's efficiency.

In the case of my 383 swap, he erased all the 350 codes and started over, reprogramming every 500 rpm or so on the dyno and on the road. Among other things he found my distributor advance was coming in 1000 rpm too late and the hot air warm-up valve on my air cleaner was stuck half-open.

In terms of drivability, performance and mileage my truck is transformed. These guys are not cheap but they will make your Suburban dance.

[custmguru]

sure makes me feel better about my 11.5MPG to 12.5MPG.

what engine do you have the 350 or the 454?

[JoeyDBabe]

Originally Posted by DDotson

Take it to your GM dealer and have the EGR valve checked. The EGR may not always come up on codes but it will darn sure kill the fuel milage.

Thanks to all of you for the comments and suggestions.

[b][color=orange][font=arial black] What is an EGR Valve?

I am more than willing to buy and switch out some parts in an effort to fix this thing, but taking it to the dealer is an idea I can not entertain. It’s like saying here is a credit card, let me know when it stops working and maybe we will have a solution. Honestly, what can they do for a well out of warranty truck that my mechanic can’t?

[JoeyDBabe]

Originally Posted by sub006

Contact Van Gordon and Brown in Claremont, California. They have a Clayton dyno and all the latest GM software. Scott Brown will trace, find and correct any problem(s) affecting your vehicle's efficiency.

In the case of my 383 swap, he erased all the 350 codes and started over, reprogramming every 500 rpm or so on the dyno and on the road. Among other things he found my distributor advance was coming in 1000 rpm too late and the hot air warm-up valve on my air cleaner was stuck half-open.

In terms of drivability, performance and mileage my truck is transformed. These guys are not cheap but they will make your Suburban dance.

This sounds like a road to a solution. Do you have a number for this guy?

[JoeyDBabe]

Originally Posted by custmguru

sure makes me feel better about my 11.5MPG to 12.5MPG.

what engine do you have the 350 or the 454?

350, dont make any sence, does it?

[sub006]

Hi, Joey!

Scott Brown's business 'phone is (909) 626-5232. Address is 150 Olive, #B in Claremont.

They needed my truck for two days (there is an Enterprise rental offfice about two blocks away).

Good luck and cheaper driving!

[DDotson]

The dealer has the proper equipment to test everything. Most garages do not have the same equipment. A diagnostics will determine if there is something wrong. No I do not work for a dealership in anyway. I work for Hershey as a mechanic. I do most of the work myself on my truck but have found the dealership diagnostic test to prove very useful. Most places only charge 40 - 70 dollars a lot less exspensive than guessing and replacing parts that are in otherwise working order. Not to mention the time and aggravation involved in replacing them. That is how I found out about my EGR, that was slow reacting to acceleration which in turn killed my milage. I went from about 7 mile to the gallon make up to 16.

[DDotson]

Oh sorry EGR is Emision Gas Recirculatory valve.

[joelseeley]

Get One With A Diesel, I Did, Gets 23mpg Cty

[joelseeley]

no its exhaust gas recirculation valve

[sub006]

Diesels are cool, especially with turbos.

Only problem is, Joey is in California where GM light truck diesels are illegal.

[custmguru]

Originally Posted by JoeyDBabe

350, dont make any sence, does it?

it makes even less now. im getting my 11.5 to 12 in a 454.

[Jimbozcrazy]

Sounds like I have the same issue with my 99. I got a 1500 with a 5.7 and the same 4X4 getting 10.2MPG in the city and I'm driving like Mother Theresa. Can I get an egr valve at autozone? I feel like I'm single-handedly supporting some middle eastern oil ministry every time I fill the bottomless 40 gallon tank.

I got no codes, no warning lights, and it runs like a champ, a very thirsty and parched champ!