I've got the 4.3 liter v6 cpi, 214k miles. it ran fine up until the other day i left it sit for about eight hours. i drove about 8 miles and came to a stop, at the light it sputtered and hesitated and almost died. i have since changed the plugs, wires, distributor rotor and cap, and the oil. i am soon to change the fuel filter. i think my oil pump may be shot because my oil pressure is always lower than 40 when the engine is warm, i have heard that maybe my spider is going bad.

all in all, it will be around 400 to fix, i spent 700 on the blazer, and have since put in like 600 (new tires, windshield, and various components).

what should i do? buy the stuff which im not really sure how to put on but have a guide for, or cut my losses and sell the truck for something else?

 

If you pull the air valve thing out of the top of the upper plenum you would be able to see down into the intake and determine if you have some kind of fuel leak. Look for fuel washing and/or a strong fuel odor. Also your fuel pump may be reaching the end of its life if it is the original one. It would be good to hook up a pressure gauge to see what's happening.

Oil pumps generally don't go bad and cause low oil pressure readings. It's usually the bearings being worn. At over 200k miles I wouldn't doubt it that the clearances are a little wide. But that shouldn't be your problem right now.

 

Yeah, I would agree. But, it's totally up to you you either buy a used car and fix crap or buy a new car and pay huge payments.

 

well the fuel pump is pretty loud but idk if that means anything. the truck does have a very strong odor from the exhaust almost as if there is a dead cylinder somewhere. it also was putting out a lot of white smoke the other night. i know that usually means burning oil but the oil level hasnt changed. thank u guys for input and would appreciate more feedback

 

White smoke is burning coolant.
Blue is oil
black is too much gas

Do a little enspection, you havent got that much into it, and its a great truck. Its easy to inspect the various components. You might want to take in mind that parts for these trucks are dirt cheap... Which makes fixing them not take too much. I have tons of new stuff into mine so far, and I dont feel that it is costing me alot.

 

well i have heard it could be the cpi unit, is that the same as the injectors?

ive also heard:
clogged caddy converter
malfunctioning spark plugs
off time

 

Yes the cpi (spider) functions like an injector, but think of it as one large injector with a supply and return line and 6 individual lines supplying fuel to each of the 6 cylinders. The spider itself is reliable and seldom needs replacement. However, the fuel pressure regulator which attaches to the spider will go bad along with the internal supply and return lines which usually fail from rubbing against one another. If you end up going this route, you can expect to pay about $100 dollars for both the FPR and the supply and return lines (GM dubbed "Nut Kit") along with a $15 plenum gasket. Search the forum and you'll find everything you need to know about this topic including how to do the repair (I'm pretty sure their is a detailed write up somewhere on this forum).

IIRC as little as 20lbs of oil pressure when warm is within specification, so no need to worry there. Of course relying on the dash gauge isn't entirely an accurate method. If you wanna be absolutely sure, check with a master gauge.

 

Alright, thanks. I have also heard my choice of spark plugs was bad, although i didn't think it would make a difference. I was recently told to change my autolite plugs for acdelco plugs just because autolite plugs foul out really quickly in gm engines and that could be causing this. i am getting a very strong gas smell and my gas mileage went from about 60 miles to a quarter of a tank to about 20 miles to a quarter. im thinking i have a dead cylinder or two.

 

I ran auto lite in my 93 for 3 years with no problems to speak of. The only plugs you should steer clear of are bosch and champion from what I have heard. Did you set the gap on each plug (.035" iirc).
Try checking you're oil level, if the oil is high on the dipstick and gets higher after driving, this is usually indicative of fuel making its way into the crankcase and can be attributed to a faulty FPR and/or internal supply/return lines. Also give the oil a sniffl test... does it smell like gasoline?

 

it's .045" i just changed them to acdelco, cleaned out my egr valve as best as i could, the oil doesnt smell like gas and the level really hasn't changed. i think the fuel pressure regulator is contributing to what's wrong but not really sure. only one way to find out though. i will take the upper plenum off soon and check it out. i'm not so sure as to what to do anymore.