Truck is still running smooth !! the motor was a Gm crate Motor assembled in Mexico
It has 123,000 miles on it, might be worth looking at the valve/rocker arm torque
Have you done a cylinder leak test on yours?

 

After I replaced the parts, I did a compression check on #6 and it was erractic. I don't remember how much it was off when compared to the other cylinders, but it was lower than the others. I don't really want to spend the money on a leak down tester, If what you did ( it will only cost me my time and a gasket) doesn't work, I am going to just pull the motor. Since I know there is a problem with that cylinder, be it the rings or valves, which means the heads have to be removed to fix it...I'll just replace the motor if it get to that point.

 

Harbor freight has the tester for under $40 Not sure if you have a store in your area but When I did a regular compression test on mine compression was equal to the other cylinders so you are probably right.

 

yes we do have one and I'm aware of the cost of it, but I'm pretty sure my fix will not be as simple as your's ...just my kinda of luck..lol. But...for what I paid for this blazer($100) and with everthing else working as it should, I think a new engine would probably be the best route.

Thanks for the replies..and I may still check the rockers. who know?..just might work,lol.

 

I own a 91 Blazer S10 Tahoe 4.3L and after having the engine rebuilt 30K miles ago at 100K - for other reasons - it began to have weird rough idle issues especially getting off the interstate - it would even surge and the RPM would hit 3K at a stop. Driving back to town, it took a half tank of gas to go 60 miles.

Anyway, all the controls, sensors, and solenoids had been previously replaced at rebuild and were tested when I got back from the trip. All was OK. So, I started looking around at other systems/components and finally discovered that the battery was the culprit. It was cracked at the bottom and had slowly drained out inside the fender wall. Battery holder plate was shot. At one point, it measured 10V and the dummy light in the dash finally came on.

A new battery - problem solved. Since the engine has an over-sized alternator, I decided to get the biggest capacity battery at 850CCA with reserve (rated at 1000 total). This will help since I am converting it into a news gathering vehicle for my job as a freelance news photog. Every photog wants a 4x4 Blazer, right? They just run and run and go anywhere.

Bottom line - I have seen enough vehicles now that fool you into thinking that a sensor went out and everything gets replaced at great expense, when one of the most obvious culprits overlooked is the battery. Scrutinize it at an auto parts store for free before any other troubleshooting. A neighbor sold me a 73 Dodge Club Cab for $100 since he could not get it to run. Since I already had one, I knew its idiosyncrasies. He spent $$$ to replace all electrical and even bunged-up the reluctor in the distributor being so frustrated. After rebuilding the distributor and replacing the battery, it runs fine.

We overlook them because we just don't realize they are doing work even after the simple task of starting the engine.

If you care to read on, I am fond of the Blazer since it was the vehicle I used primarily in my first career position in news in 1989 while shooting at NBC in Las Vegas. So, this Red on Black blazer hand-me-down is being tricked out for news gathering. Blacking out the windows with limo tint, adding a sun visor with flashing caution lights, the back fold down seat is coming out as I got a used matching bucket seat to add to the back transversed style - it will face an editing console built upon a 19" rack with power inverters and micro A/C supply. The rear driver's side door will give access to the rack's back side for electrical connections. A cargo net will divide the cargo area that will have a sliding tray for camera, light kit and tripod. Antennas will go on top but I will probably eliminate the age-old 2-way radio since it is not private and most photogs are using cell phones with discreet numbers to connect to the newsroom anyway. A laptop with 3G wireless will be integrated into the cab to swivel left/right for the reporter/producer to write while travelling. A micro sized doc scanner was picked up at a second hand store and I am planning to install a micro sized fax/laser printer combo. This system would be predicated upon the fact that wireless internet existed in the areas travelled. A GPS unit will reside in the rear-view mirror area (actually looking for an overhead console to mount it in), but who really wants to mount a GPS on top of the dash since it is hard to see being farther away and it vibrates. Guess I will get the one that speaks to me as well. GPS and MapQuest will be a savior for me since it was hard reading maps at 120MPH at night while on high speed chases thru Vegas/CA/AZ back in the 80's. Oh yea, the cell phones were like big huge bricks too. Nowadays, the personal pager has been practically eliminated. The laptop will enable me to check my calendar to accept a job in a block of time for that day and then receive the PDF Purchase Order digitally signed (on my website) that I will receive by email and print out to add to my invoice for Accounts Payable dept. Going paperless is another big theme here - perhaps the AP dept will allow an electronic invoice via email...

Last but not least (but almost), I am looking for a portable ENG/EFP microwave setup to beam back the footage captured in the field. If I need to install a satellite setup, then I will start over with a Suburban!.....Hmm....