6.2L L94 & 6L80 into my 1992 Blazer

[NTYHOE]

Thanks for the update!

 

[Nak]

Had a few problems. I was missing a couple of breakouts on the harness, not a big deal--easy enough to add. Then I realized my fuel sender was wrong. I switched to a '98 tank to get the 40-250 ohms fuel level sender. Here's the problem: '98 till about 2004 is 40 ohms empty and 250 ohms full. After 2004, 40 ohms is full and 250 ohms is empty. (I need the ECM to have the correct fuel level because of my plans for my instrument panel.) Anyways, after some research I figured out how to calibrate the ECM for a reverse fuel curve with HPTuners. After some tests it looks like it works fine. Hopefully I won't have any issues down the road with the fuel sender curve being reversed. (I want things like fuel mileage and distance to empty to work properly.)

So, I'll finish wiring the fuel sender tomorrow--maybe an hours work--then I'll fill the fuel tank one gallon at a time so I can calibrate the fuel level. After that I've got just a few small things to do; so barring any problems I'll start her in the next day or two.

 

[SunlitComet]

The scanguage 2 has trip computer functions that will get you your readings.

 

[Nak]

The scanguage 2 has trip computer functions that will get you your readings.

I understand that, but I will want my readings on my dash. My main concern is that the reversed fuel sender curve may cause problems with those or other readings. I don't know that it will, but as of yet I haven't been able to verify that it won't. For instance, having the MAF curve reverse anywhere can cause the engine to die as it passes that point in the curve. I just have no idea if a reversed fuel sender curve can cause problems; I'm guessing that only someone who has done it would know for sure. Anyways, soon enough I'll post my results up and anyone trying this down the road will know.

 

[Nak]

Getting close. I filled and calibrated the fuel tank, installed the intake and a few other details. I pressurized the fuel system and no leaks! Yay!

Here are the calibration values for a 1998 fuel tank & sender with a L94 engine. Your numbers may be slightly different, but these should get you pretty darn close:
Empty, 14.2%
1 Gallon, 14.2%
2 Gal, 16.4%
3, 19.2%
4, 22%
5, 23.6%
6, 25.8%
7, 27.4%
8, 29%
9, 31%
10, 32.6%
11, 33.8%
12, 35%
13, 3.2%
14, 37.2%
15, 38.4%
16, 39.6%
17, 40.8%
18, 41.2%
19, 42.8%
20, 43.6%
21, 44.4%
22, 45.4%
23, 46.2%
24, 47%
25, 48.4%
26, 49.2%
27, 50.2%
27.5, 50.6%
28 - 30 gallons, 50.6%

 

[Nak]

Started her up tonight! Some problems though... First, I get a DTC "No comm with TCM" and the transmission won't go into gear. I'm thinking I'll have to have my TCM reflashed at a dealer. Second, I show nothing for oil pressure or temp. Not low or zero, nothing. I'm guessing there's a problem with the harness. Third, One of the trans cooler fittings I had welded up is leaking at the weld. That'll have to come off & get re-welded. Fourth, I have no tail lights at all. No brake lights, turn signals, etc in the rear. I'll have to trace that one down.

Other than that she ran rough for a while but is running fine now. The exhaust sounds excellent, at least at idle with minor revving. Very quiet. Hopefully the valves in the mufflers will open open--like they are supposed to--during hard runs.

I'll get a first run video up soon along with a few more pictures.

 

[SunlitComet]

follow the dtc codes diag procedures to the key and apply changes to them as it interacts with the vehicle wiring and you will locate the issue. why do you think the tcm needs reprogramming tho?

 

[Nak]

follow the dtc codes diag procedures to the key and apply changes to them as it interacts with the vehicle wiring and you will locate the issue. why do you think the tcm needs reprogramming tho?

Already fixed everything but the tranny not going into gear. As far as that goes, It's either an OS compatibility between the TCM and the ECM--most likely I think--or a VIN incompatibility--Less likely I think. Either way, It's going to take a re-flash at the dealer to get the TCM and the ECM talking. Also, the diagnostic procedures completely ignore those issues as they wouldn't exist in a factory vehicle.

 

[SunlitComet]

they have codes. even for the ram and rom's in them.

 

[Nak]

they have codes. even for the ram and rom's in them.

Yes there are codes. It's just that the diagnostic procedures assume compatible OS's and VIN's. So when you get a U0101 code, the diagnostic procedures never mentions OS's or VIN's; the manual assumes those are correct. (And yes, I checked out the procedures in case it was something else.) But when you do an engine swap and change the OS in the ECM and have a random OS in the TCM, they may be incompatible. Not to mention that my harness has components that definitely aren't factory.

The ECM OS was changed to accommodate the brake switch in my 1992. The original OS required a variable voltage from the brake pedal switch for factory cruise control to work. Since that would be exceedingly difficult to retrofit into my 1992, we flashed an OS that used two wires from the brake pedal; one 12v when brake off, one 12v when brake on. That switch was already in place from the factory on my Blazer.

Depending on who you talk to, either the mismatched VIN or the mismatched OS, or something in the tune is responsible for my issue. It's not covered in any manual outside of internal GM engineering documents, so you have to rely on people with experience. A re-flash by the dealer will address all three possibilities, so it's the logical next step. I'll just have to bring my Laptop with me so I can disable VATS with HPTuners after the re-flash. I'll also have to change a few other things too: Fuel Pump control, alternator control, & a couple of misc items. I'll disable DOD/AFM for the first 1,000 miles as well so the engine can break in properly.

If it was just the VIN, EFIlive would be able to fix the problem. But a re-flash by the dealer will be cheaper than buying EFIlive. I could chase this problem for a long time, or fix it with a tow and a $109 flash at the dealer.

 

[SunlitComet]

Maybe I should do this to a hoe some day when I have the cash for another one and the parts for the swap. I bet I could make this work with ease. but no extra toys to play with. btw, why not leave in the existing pcm for the cruise control? no room?

---------- Post added at 11:08 AM ---------- Previous post was at 11:06 AM ----------

also how about a linear range transmitter for the brake issue.

 

[Nak]

Maybe I should do this to a hoe some day when I have the cash for another one and the parts for the swap. I bet I could make this work with ease. but no extra toys to play with. btw, why not leave in the existing pcm for the cruise control? no room?

The L94 is DBW, so a cable cruise would be worthless. BTW, DBW is required for DOD/AFM

also how about a linear range transmitter for the brake issue.

Why? It's much easier to swap out the OS. As far as there being problems with OS compatibility, that's just part of the swap.

The more complex you make the swap, the more complex the problems. I chose to go very complex. Complete factory emissions. DOD/AFM. Factory cruise, TU/TD shifting. Tow mode. BCM. These are all things that aren't required, but things I wanted that added to the complexity of the swap. Plus, it's going slow because I'm restoring as I go along. I'm replacing all of the factory wiring with Ancor marine grade wire. I have to do extra things that aren't normally done, like getting the fuel level to the ECM. I need that for future mods I plan on adding. (Flat panel displays for gauges, Nav and music.)

 

[SunlitComet]

You are not going to put an ipad in it are you?

---------- Post added at 06:04 PM ---------- Previous post was at 06:04 PM ----------

how about a car computer?

 

[Nak]

IT'S ALIVE!!!

Turns out it was the internal shift linkage. Interesting, because the trans was supposed to have come from a running vehicle. Not possible. I'll get videos up, but here are my impressions: The Dynomax VT mufflers sound great at level ground cruise and wide open throttle. Lot's of drone at uphill cruise. The valves need to be sprung stiffer. I really need a tune, because off the line is obviously restricted somehow. Once you're rolling, HOLY CRAP! The factory electric fans were well worth the effort. The Improved Racing engine oil cooler and trans oil cooler thermostats work great and are well worth the effort & cost. The factory truck DBW throttle needs a heavier spring. Mandrel bent dual exhaust sounds incredible at WOT. Setting up the steam vent as the engineers intended is worth it.

 

[SunlitComet]

Congratulations. Perhaps torque management is getting in the way or possibly the converter stall.

 

[Nak]

Thanks! Yeah I thought it was probably torque management. I raised the torque limit in all the gears way up and disabled traction control. HOLY CRAP! It's fast off the line now. 0-60 in 6.0 flat according to Torque, and the tune isn't even close to being optimized right now. I should easily be able to shave .5 off of that down the road. That'll have to wait until she's broken in though.

 

[SunlitComet]

Not broken in yet and you 0-60 it already?
You must use the ways of the force and have patience. Mind what you have learned. Save you it can. You will know when the drivetrain is ready for hard work... when you are calm, at peace, passive.



At that point Smash the throttle.

 

[Nak]

Actually I have the shift points set pretty low for break in. Even at WOT it's shifting at 4000. I'm a big believer in various cylinder pressures--including high ones--during break in. I think the higher pressure helps seat the rings properly. (That's also why I've disabled DOD for the first 1000 miles.) It's worked for me in the past. The 350 that came out at 224K Still had excellent compression and burned no oil.

 

[07Burb]

very cool project! Not many people do the 6.2 so that's really cool!

 

[Nak]

Thanks! Yeah, I stressed the expense a bit, but as soon as I drove it with Torque Limits disabled I decided it was totally worth it! Just light throttle and it leaps forward like my old Corvette.