6 miles to the gallon what is wrong

jdwells80 · 09-04-2005, 09:27 PM

OK where do I start... I bought a 95 vortec 4.3 blazer (vin w) at an auction about 7 months ago. It had 178,000 miles when I first bought it and now it has 184,000 on it. The truck was running bad then and as I started changing things out it seemed to fix little problems but brought the bigger problem to the forefront. The truck gets 6 or 7 miles to the gallon right now and with gas being 3.30 a gallon I can't afford to drive it. It takes almost 45 seconds to get up to speed on the interstate. The engine is burning rich, you can smell gas from the exhaust almost like fresh gas is pouring out and not being burned at all. There is a white smoke coming from the exhaust while I am driving. I changed the spark plugs about a month ago after a compression test and found that cylinders 2,4,6 spark plugs were excessively carbonized for only being in the engine for about 6 months. So far I have done a fuel pressure test and the pressure was at 64 psi, which according to the book is exactly what it should be. I also did a dry compression test on it and don't remember the exact numbers but all cylinders were within 5 psi of each other which tells me my cylinders, pistons, etc are good. I have also changed out the MAP sensor, EGR valve, O2 sensor, passenger side knock sensor, catalytic converter, muffler, spark plugs and wires, distributor cap and rotor, transmission fluid and filter. I change my oil every 2,000 miles and haven't noticed any excessive oil consumption. I have asked other friends of mine that have more experience working on cars and they are all stumped I don't know what to do and I don't want to give the dealer $120 to put it on a diagnostic if someone can help steer me in the right direction.

BlazerLT · 09-05-2005, 01:14 AM

Please use the search feature for:

tune up

CPI injector

Nut Kit

EGR Valve

jdwells80 · 09-05-2005, 02:01 PM

Blazer, I pulled the upper intake plenum off today and checked the fuel injectors, there was washing inside the passenger side of the intake manifold. According to the forum on the fuel injectors that means there is a leak in the injection system, so I am going to buy the new CMFI assembly this payday and change that out. My question is do I also need to change the nut kit or will the CMFI assembly be enough?

BlazerLT · 09-05-2005, 03:05 PM

While you have the upper plenum cover off you might as well replace them as well seeing they fail too.

Also, you do know you need to replace the upper plenum gasket when you remove the top cover right?

You can't just take it off and replace the top with the old gasket.

Read here for some more information.

http://www.s10forum.com/forum/showth...pi+replacement

jdwells80 · 09-05-2005, 03:30 PM

On the link you showed me it said you got the gasket, cpi and nut kit for $310 did you get it from a dealer or auto parts store? I am having trouble finding a nut kit online.

BlazerLT · 09-05-2005, 03:48 PM

the nut kit is a dealer only item.

The injector can be purchased off of ebay for cheap.

jsgold · 09-05-2005, 07:29 PM

Here, call this guy. He is a dealer that sells on Ebay. will sell you the gasket and nutkit with the spider. Cost $305 frt ppd. If the Ebay ad expires, don't worry, he sells them all the time. best deal by far for GM CPI stuff.

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT

BlazerLT · 09-05-2005, 08:06 PM

Quote:

Originally Posted by jsgold

Here, call this guy. He is a dealer that sells on Ebay. will sell you the gasket and nutkit with the spider. Cost $305 frt ppd. If the Ebay ad expires, don't worry, he sells them all the time. best deal by far for GM CPI stuff.

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT

Is that with shipping and everything included?

jsgold · 09-05-2005, 08:28 PM

Yes. I do not know if he charges more for shipping to Canada, but he includes paid shipping for his spider kits shipped in US for sure. When I asked him for a price for the nut kit and gasket, $305 with freight paid (ground) was what he quoted. Note - I bought this set up for my 93 in December, when I thought mine had died. When I found (at the time) it was OK I sold it for what I paid for it. Of course I should have kept it as now mine IS failing, but, I could not keep that much money tied up when I had no idea when I might need it. If I could just get a crystal ball!! Anyway, this guy shipped quickly and will be selling me another here in few days.

BlazerLT · 09-05-2005, 08:35 PM

You should go for it.

Good deal.

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