Eratic behavior from an 85' 6.2 (more below) requesting help please (Two vids in one)

[nycxjeremyy]

Rockauto is full of chineesium knockoffs and copies of the "real" parts. you have to be careful what you but from them..

this makes me lean more towards you having a failing lift pump. as well as possibly needing to replace the rubber hose that feeds this pump too!

Guess I'll add this to the stuff I'll need to check next weekend on pass

 

[dbrannon79]

that part is cheap enough to get another one to install along with keeping a good spare in the rig in case you need it on the side of the road!

 

[Will L.]

Ok, when that starter finishes burning out - you almost did it there- don’t buy a regular starter- powermaster 9052. Crank times to keep starters alive:
30 seconds on
30 seconds off
30 seconds on
30 seconds off
30 seconds on
30 MINUTES off

Your buddy is possibly right - but misdiagnosed ip (injector pump) is the most common error that had more mechanic shops in court for gm than any other gm item. You HAVE TO DO the clear line test first, along with the fuel pressure at the ip inlet. Get the fuel pressure gauge tapped in after all the rubber lines. Not one inch of old fuel line between the gauge T and the ip.

Pull a sample of fuel (one pint minimum) from the water in fuel drain into a glass container and let it sit undisturbed for 10-12 hours then inspect for contamination.

LP (Lift Pump) GM ditched the mechanical LP on these engines because of a few issues. The main one is when the bladder has a minor tear the engine can still run but the pump is leaking fuel into the crank case. Thousands of engines replaced under warranty. I don’t remember the year it went away but remember my 88 they were gone. I have been told they solved the issue, never was able to verify. It would be nice if so for the db2 ip as it is adequate fuel delivery.
If you remove the pump, also remove the push rod that will slide out automatically. A simple block off plate to seal the oil leak bolts on just like the ones for small block and big block chevy uses. If you choose to continue running the mechanical lift pump, frequently smell your dipstick for diesel. If you smell it don’t run it, replace LP and do oil change immediately.

The best of the $100ish inline pumps like the one Doug posted is the AC Delco EP158. Run it off 10 awg wire with a fuse and relay activated when the ignition is on. Later year trucks run them off an oil pressure sensor. This is often touted as part of the dot regulation that came along in 1990/1991 that when a roll over occurs the fuel supply will cut off. And is touted as why the mechanical LP went away This was achieved by lost oil pressure stopping power to the lift pump - but fails to function because the running engine will continue to draw fuel past the LP as it is purposely designed as “flow on fail” so 100% loss of oil pressure will not stop the flow of fuel anyways. You do the math on which side is more plausible.
There is far better LP and filtering options but cost WAY more. Do the tests then lets find out what ya need.

What type of lubricant / additive have you been adding to the fuel besides the one gelled fuel event?

Oh, and Doug is wrong. That Blazer is no good but I would be willing to help you out and give you $100 haul it away for you! Haha . We do love pics of nice rigs and yours surely seems to meet the requirements!

 

[nycxjeremyy]

Ok, when that starter finishes burning out - you almost did it there- don’t buy a regular starter- powermaster 9052. Crank times to keep starters alive:
30 seconds on
30 seconds off
30 seconds on
30 seconds off
30 seconds on
30 MINUTES off

Your buddy is possibly right - but misdiagnosed ip (injector pump) is the most common error that had more mechanic shops in court for gm than any other gm item. You HAVE TO DO the clear line test first, along with the fuel pressure at the ip inlet. Get the fuel pressure gauge tapped in after all the rubber lines. Not one inch of old fuel line between the gauge T and the ip.

Pull a sample of fuel (one pint minimum) from the water in fuel drain into a glass container and let it sit undisturbed for 10-12 hours then inspect for contamination.

LP (Lift Pump) GM ditched the mechanical LP on these engines because of a few issues. The main one is when the bladder has a minor tear the engine can still run but the pump is leaking fuel into the crank case. Thousands of engines replaced under warranty. I don’t remember the year it went away but remember my 88 they were gone. I have been told they solved the issue, never was able to verify. It would be nice if so for the db2 ip as it is adequate fuel delivery.
If you remove the pump, also remove the push rod that will slide out automatically. A simple block off plate to seal the oil leak bolts on just like the ones for small block and big block chevy uses. If you choose to continue running the mechanical lift pump, frequently smell your dipstick for diesel. If you smell it don’t run it, replace LP and do oil change immediately.

The best of the $100ish inline pumps like the one Doug posted is the AC Delco EP158. Run it off 10 awg wire with a fuse and relay activated when the ignition is on. Later year trucks run them off an oil pressure sensor. This is often touted as part of the dot regulation that came along in 1990/1991 that when a roll over occurs the fuel supply will cut off. And is touted as why the mechanical LP went away This was achieved by lost oil pressure stopping power to the lift pump - but fails to function because the running engine will continue to draw fuel past the LP as it is purposely designed as “flow on fail” so 100% loss of oil pressure will not stop the flow of fuel anyways. You do the math on which side is more plausible.
There is far better LP and filtering options but cost WAY more. Do the tests then lets find out what ya need.

What type of lubricant / additive have you been adding to the fuel besides the one gelled fuel event?

Oh, and Doug is wrong. That Blazer is no good but I would be willing to help you out and give you $100 haul it away for you! Haha . We do love pics of nice rigs and yours surely seems to meet the requirements

quite alot too read, main takeaway from this is to definitely switch over from the mechanical pump to an electronic one (which, knowing my mechanical skills, will be a fun endeavor.....)


Ill definitely do the clear line test before I do anything huge of the sort (though, I already have an IP coming in from a friend who owns the CUCV varient of the 6.2, practically gave it for free) Ill see how it goes next week and I'll post an update when I can

 

[jrsavoie]

Id like to thank you all for your help in this matter, this is really narrowing it down and hopefully next week on weekend pass (military) we can do the clearl line trick and see once and for all if it is indeed air in the system

the DiY shop on base actually has an old head army mechanic (I'm AF) who did tell me to look into replacing the Fuel Pump and Lift Pump as both are certainly old and dated and it could also help perk it up, i may look into that aswell

And for clarification, my Motor is an 85 (mechanical pumps, etc) while the Blazer itself is a 90s one, the motor was swaped out by the previous owner
View attachment 91821

Nice ride.
Did it start life as a gasoline powered machine?

What year is it?

What fuel filter do you have?

Where does the turbo return oil go?

There's adapters / hose barbs that screw into the EP158 ift pumps. I believethey canbe found in the help section at the autoparts stores.

 

[jrsavoie]

Lift pump adapter / hose barbs to EP158

Dorman 800-170 3/8" x 4" Steel Fuel Line Repair

https://www.amazon.com/gp/aw/d/B001EIXQ6C?psc=1&ref=ppx_pop_mob_b_asin_title

 

[nycxjeremyy]

Nice ride.
Did it start life as a gasoline powered machine?

What year is it?

What fuel filter do you have?

Where does the turbo return oil go?

There's adapters / hose barbs that screw into the EP158 ift pumps. I believethey canbe found in the help section at the autoparts stores.

It used to start as easy as one, if that's whats being asked here

1985 6.2, and a WiX one off of O'riellys

 

[jrsavoie]

It used to start as easy as one, if that's whats being asked here

1985 6.2, and a WiX one off of O'riellys

I am curious as to whether it came from the factory a diesel or a gasser?

What year is it?

I was asking what style of fuel filter it has? - looks like you have an aftermarket fuel filter on the passenger side firewall.

 

[MrMarty51]

I am curious as to whether it came from the factory a diesel or a gasser?

What year is it?

I was asking what style of fuel filter it has? - looks like you have an aftermarket fuel filter on the passenger side firewall.

If it was a gasser, at least they changed the brake booster to the hydro boost.
Could have run a vacuum booster from a vacuum pump. Maybe ? If there was such a thing on this old of a truck.

 

[jrsavoie]

If it was a gasser, at least they changed the brake booster to the hydro boost.
Could have run a vacuum booster from a vacuum pump. Maybe ? If there was such a thing on this old of a truck.

I missed that. Not sure on the year. 1988 or 1989 should have had the factory electric lift pump, so it shouldn't be to hard to plumb.

 

[MrMarty51]

I missed that. Not sure on the year. 1988 or 1989 should have had the factory electric lift pump, so it shouldn't be to hard to plumb.

And I think those years probably run the old rectangular FFM on the radiator support.
Wonder if thats still there, like a backup filter.

 

[jrsavoie]

And I think those years probably run the old rectangular FFM on the radiator support.
Wonder if thats still there, like a backup filter.

My 1989 was the brick filter on the back side of the engine

A lot of people cussed the brick filters. I never had an issue with mine. Changed every oil change/ 20,000 miles.

 

[dbrannon79]

I see it looks like you have an aftermarket turbo. would you mind telling us about it?

 

[Will L.]

DEFINITELY do the clear line, the fuel Pressure tests and sample the fuel before installing the new to you db2. If you are contaminated with algae you can contaminate the new one.