Vehicle: 93 Chevy Blazer S-10 4x4 Vin: W Vortec 4.3L 262Ci


Issue: Fuel in Exhaust

Symptoms: Rough Idleing, , 8 MPG Milage, Stalls and nearly Dies when Taking off from Dead stop, after warming up requires gas pedal to be down to start, Loses Power and Backfires through exhaust when run on interstate after about 20 miles

Diagnostics and repairs done without a Change in Symptoms:

New Plugs, Wires, Rotory Button, Distributer Cap
New Nut Kit, New Fuel pressure regulator
New Starter
New Transmission Filter and fluid and gasket, New Oil Change

Maintains 60 pounds of fuel pressure w/o Leaking off while key on not running, while idleing and while Running

Garage is going to use a scan tool to read what computer says about voltages ect. I do not have those results yet.
Garage is gonna Check Vacuum pressure, I do not those results yet.

I have this information spread out across different forum threads However Now I have Compiled it and some issues have been resolved while This one Haunts me.

Anyone Have an Idea on what or how the gas could be getting in exhaust?

Would being slightly out of time cause this?
Would a single fouled out spark Plug cause This?
Is There a way to have a gas leak and also maintain 60 pounds of pressure inside plenum? This issue is like beating a dead horse the answer is hiding and wont budge to come out and be found.

I want to Thank swartlkk, ely069, mikeymoe, and a few others who have given sound information which how i came from so many threads to this one issue. Now I hane this over to The professionals for answers LOl you guys are great

 

Have you put a timming light on this? If you replaced the j-connector to the CPI and have done a compression test and all is well then bad timming would explaine everyone of your symptoms. If the light bounces all over the place, then its one or both...bad distributor drive gear or the chain has jumped a cpl of teeth. Easy way to check for both if that's the case.

 

The only thing I can think of is maybe a sticking or broken exhaust valve. That could explain no lose of fuel pressure.

 

My first CPI unit was failing not on the nuts or FPR, but the nozzle itself was continually spraying, fuel pressure was ok, I drove it home from where i bought it and had been sitting 2 years, but would not restart very easy. I had all the same symptoms you have - crappy milage, no power, stinky enhaust dripping fuel out the tip. Used a junkyard injector unit that lasted about a year before somethings leaking really bad again. I never did get a pressure test back then cause I could see a couple spraying - Im talking really spraying good, it was allover the place. It was 3 and 4 that were spraying on me. Might wanna open the top and pop the nozzles back out and watch them when you turn the key on, they shouldnt do anything. Careful squeezing the little tabs that hold them in they will be old and fragile. Squeze them together and pull straight up and out. They will want to point back into the hole, but thats OK, if they are leaking you will know it as soon as you turn the key on.

 

ok, plenum is wet on wet on Passenger side However no fuel is leaking from FPR, nozzels or lines and no fuel sprays from nozzels when key is turned on, after new nut kit now its dry as Powder on drivers side (yea).

So while fuel in exhaust is an issue ( most likely due to dead cylinder)

Here is what mechanic said when i started truck and bubbles ran to the overflow tank immediately, Son You got a blown headgasket or cracked head.

Looking back retrospectively ( White exhaust when sitting idle for a bit, smelled of gas fumes when running or idle)

Because many of you have had these trucks and rebuilt them, what is most likely? gasket or cracked head, and would a bad lower intake gasket have same effect ( letting air in cooling system)? Would any of these create a dead cylinder?

Keep The Good answers Coming You Guys are Great
I am calling the place I got My Engine From ( Junkyard ) and seeing if they will replace it. If not im wondering from you experienced folks what the most ikely results are gonna be.

This is a 1993 Chevy S-10 Blazer 4x4 4.3L 262Ci Vin:W, does it have screwed in or pressed rocker arms?
Is this an issue that is often seen on these trucks?

 

I think it would be worth it to get a block tester and test for exhaust gases in the coolant. That would confirm that there was either a cracked head or a blown head gasket. They're not too expensive and they're easy to use on these trucks. Put the fluid in the tester and suck some air out of the radiator neck. Another test I would do, if you haven't already, is a compression test on all cylinders. If you have two adjacent cylinders with low compression that will point to where the problem is.

You may also want to check the coolant temperature sensor since the truck's computer uses that to compute how much fuel to give the engine. Test the resistance to see if it matches the spec for the given temperature of the coolant.

As any of the more experienced guys on here will tell you, good diagnostics is the most important part of repair.