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GMTD scan tech

Will L. said:
Tons of people did mess with the rear cooling ports. Tons of problems.
Gm tried as well and did every conceivable combo and return location including reverse flows. It shifts the problem to other parts of the cylinders and or heads.
After spending many millions of dollars they came up with the balanced flow waterpump & system. The current pump is the 4th version. GM is all about the simple fix for cost reasons- if the “rear head cooling kits” worked - they would have done it . I worked for the company that was contracted out to GM in the process when they found the solution. The new pump, dual stat crossover with bypass restrictor fitting to equal out the flow and limit volume returning to the engine while minimizing cavitation in the pump. A full bypass thermostat is better but they already had the dual in manufacture mode so stayed with it. Heavy RVs and emergency generators got the blockoff crossovers.

Just type balanced flow in the search and you can read for weeks to learn it all.
Click to expand...
Thanks Will that’s very interesting. I am curious I’ll check it out.
 
Hey all, I’m chasing a shxx load of DTC on my new Optimizer build. Haven’t started it up yet. Just cranked it over a little to check the starter after that I found the codes. After troubleshooting the codes I’ll have to crank it over a bit ( not trying to start it) and recheck for codes. Can I damage the LP by just cranking the motor over ? I do not have any fuel in it and I have a new fuel lines and tank. The new GM8 turbo I installed came with a little oil to put in before start up. That’s why I thought about it. Thanks.
 
Hey all disregard my last post #22. Of course I will damage the LP turning it over depending on how long I crank. That was a stupid question. I think I was just panicking. I continue sorting out these codes. I’ll probably be back on here 💁 Thanks
 
Thanks jrsavoie, I meant IP instead of LP my bad!! I was worried about cranking it over w/the new IP spinning w/ no fuel in it. So a filled the IP up through in input line while cranking. So the first time I cranked it over to check the starter I stuck the Tech 2 on and pulled a bunch of code up see post #17 and #18. Recorded them, cleared them, because I left the PDM, OPS and GP relay wire connectors off. Then I just did a KO scan and a DTC #17 High resolution circuit, stopped for the day. So I went out there to today hooked up the connectors I left off 💁 oop,s.
Checked all the input sensors for reference voltage, cleared #17 and unhooked LP (no fuel in it) and cranked it over for a few seconds and it hissed and popped probably because I left the plastic cover on the new TC inlet (no air 😎). Rechecked and no DTC,s 👍. Still have until Sept. 30 to return the scanner see post #17. Maybe I should have checked it w/my plug in code reader. Just need to put fuel in the new tank hook up LP and bleed fuel system of air and try to fire her up at last. Already have all the fluids in it. Anybody out there have a good way to bleed the fuel system without a big mess? Am I missing anything on a fist start up
 
Goose57 said:
Thanks jrsavoie, I meant IP instead of LP my bad!! I was worried about cranking it over w/the new IP spinning w/ no fuel in it. So a filled the IP up through in input line while cranking. So the first time I cranked it over to check the starter I stuck the Tech 2 on and pulled a bunch of code up see post #17 and #18. Recorded them, cleared them, because I left the PDM, OPS and GP relay wire connectors off. Then I just did a KO scan and a DTC #17 High resolution circuit, stopped for the day. So I went out there to today hooked up the connectors I left off 💁 oop,s.
Checked all the input sensors for reference voltage, cleared #17 and unhooked LP (no fuel in it) and cranked it over for a few seconds and it hissed and popped probably because I left the plastic cover on the new TC inlet (no air 😎). Rechecked and no DTC,s 👍. Still have until Sept. 30 to return the scanner see post #17. Maybe I should have checked it w/my plug in code reader. Just need to put fuel in the new tank hook up LP and bleed fuel system of air and try to fire her up at last. Already have all the fluids in it. Anybody out there have a good way to bleed the fuel system without a big mess? Am I missing anything on a fist start up
Click to expand...
Jumper the
lift pump, run the IP return line to a container.

Open the drain T - run it to a container. Run until you're out of air.

Close the drain T, crack the bleeder on top of the filter. Hopefully your filter is one with the real life bleeder - some don't have a hole through the bleeder and the fuel will run around the bleeder threads.

Put a hose from the bleeder to a container and bleeder the air off there.

I somehow took the hose off the IP input, I forget how I controlled the fuel, I ran fuel out the supply hose and connected it. Kind of all at the same time. Lots of rags to minimize fuel mess.
My wife ran the underhood toggle switch that runs the lift pump.

With the lift pump running, I rsn the IP return line to a container.

Then jumpers the fuel shut down solenoid or turned the key to run
And left it that way for a good long time before cranking things over.
 
How long does it take to get fuel to the LP w/empty fuel tank and fuel lines? I’m concerned about damaging LP with no fuel runners no to it. What about bleeding air out of the injectors? I’m asking all this because sometimes I can’t access the Tech Library thanks
 
"How long does it take to get fuel to the LP w/empty fuel tank and fuel lines?"

The LP can't pull fuel from an empty fuel tank. Sorry, couldn't resist.

Once there's fuel in the tank, it doesn't take long at all for the LP to do it's job and running the LP dry won't hurt it until it primes. Either key "On" (not start or cranking) or using the 12v Lift Pump Prime connection as jrsavoie outlined in post #26 will work fine.
 
Open your bleeder on the FFM when running the LP (lift pump) and purge air there first before cranking. then after closing the bleeder on the FFM, loosen the injector lines on each injector or those you can get to with the turbo in place. also if using a clear hose on the IP return you will see that the IP has filled. crank with the injector lines loose at the injectors till you see fuel leaking from them. then tighten up the lines and you should be ready to fire off the engine. it will still crank a little bit, stumble and stall once or twice, but should ultimately bust off and run.

Just let your starter cool in between cranking sessions and batteries hot if it takes more cranking to get the IP pushing fuel.
 
Will L. said:
My favorite is open ffm bleeder, let the LP prime until its good.
Remove glow plugs power to glow controller. and crank till ya see mist in the air. Install plugs and fire up.
Click to expand...
After confirming fuel at the FFM, we did the glow plugs removed and disconnecting the glow plug controller for BigT's first start.
Took just two 10-15 second iterations before we got mist.

 
Thanks guys for all the good input. That’s why I like coming on this site. That’s OK Paveltolz you can have fun at this old man’s expense, I am on Medicare you know. I have hoses and bottles at the ends at the FFM bleed and also the drain and the bleed tee. I do have the clear return line on the IP will I see fuel in the return line without cranking? I also have a spin on fuel filter kit before LP. I guess I should fill that up too. Yes Will I like the GP removal method especially since I have the wheel wells off😎. I just have to remember to add more trans. fluid only have about 5 or 6qts. in there, also squirt in the oil syringe that came w/ the turbo. I have the cooling fan off it should heat up quicker ( I will pop it on when it starts to get hot) to do the timing procedure on the Tech 2. I also have the IP solenoid straight up. Speaking of timing procedures, all I can find on all of the 6.5 sites are Tech1 procedures the one I should be using (95’ OBD1) and Tech2 procedures for the 96+ OBD2 trucks. I’m assuming that I can use the Tech2 procedure because it comes w/ the OBD adaptor. I’ll keep you guys posted. Thanks guys.
 
On the glowplugs - are you familiar with how to remove swollen ones?
If you choose to replace them with ew while out-AC Delco 60G ONLY from an authorized dealer. The 60G plugs take a few seconds longer but never swell up.

Old or New- always add antiseize on the threads before installing.
 
Oh crap, I just tested the fuel lines for leaks and the shut off solenoid . Hit the switch on the LP harness and the fuel pressure went up to 10 psi I forgot to energize the shut off solenoid oops! Yes Will I have new ones already installed in the new Optimizer. I do believe they are AC Delco 60G,s. It’s been so freaking long ago when I installed them. Life get in the way. Yea I used anti-seize also on the GP,s. Thanks Guys.
 
Paveltolz said:
After confirming fuel at the FFM, we did the glow plugs removed and disconnecting the glow plug controller for BigT's first start.
Took just two 10-15 second iterations before we got mist.

Click to expand...
Did you guys remove all the GP,s ? The exhaust down pipe will have to be removed (on the passenger side) to get to 2 of them. The starter is on that side also. Were you worried about sparks w/ the diesel mist? I probably will be doing this by myself. I try to fab up a hose or tube system to screw into GP threads to direct the mist away but that’s a lot of pressure. I do like this GP removal procedure to prove all the new injectors are working. No guess work. Thanks .
 
Goose57 said:
Did you guys remove all the GP,s ? The exhaust down pipe will have to be removed (on the passenger side) to get to 2 of them. The starter is on that side also. Were you worried about sparks w/ the diesel mist? I probably will be doing this by myself. I try to fab up a hose or tube system to screw into GP threads to direct the mist away but that’s a lot of pressure. I do like this GP removal procedure to prove all the new injectors are working. No guess work. Thanks .
Click to expand...
All GPs were removed. The exhaust downpipe wasn’t installed until after we confirmed fuel present and the Glow Plugs, specifically #8, were re-installed.
The starter is a non-issue being under the motor and well away.
No worries about diesel mist igniting. Not enough heat and zero compression to create an ignition source and we only spun the motor until the mist was present. The video was a quick repeat for the sake of making a video.
We then installed the glow plugs and the shields on #4 and #6. BigT drew the short straw and got the passenger side.
 
You can do it with 6 removed.
The idea is dropping the compression makes the engine spin faster so they will prime easier.
If all the plugs are new enough that you are reinstalling them- leave the two hard ones.
 
jrsavoie said:
If I remember right, we only removed the 4 easy glow plugs.

We didn't crank much at all. It was a brand new engine and injectors. We reused the IP. Bled everything as I described previously.
Click to expand...
Brand new injectors needs to be tested before installing them.
Last set I bought, 2 out of 8 would pop. Those 8 would just squirt a solid stream.
I sent them to an INDY shop and when I got them back everyone of them would pop at 1950 pound.
 
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