I have a PCM out of a 2005 Denali that has been flashed for VATS your are welcome to try, I shouldnt need it in the immediate future.

Mark

 

Thanks Marky522, I'll PM you about it!

Here's another clue:
So, I did the 30 minute relearn procedure for the truck (crank engine, 10minutes on ign, off for 5 seconds, repeat 3 times) and on the 4th try, the engine sputters and starts for about 8 or 9 seconds and then shuts down.

I can make the engine do this again. It's done it twice already with this 30 minute relearn procedure.

What does this mean?

 

You are talking about the Security relearn? If you have the VATS disabled it shouldn't have any effect. The only reason I can think it running longer is maybe fuel is being injected each time you turn on the key, so it runs a little bit once you try to start it.

I am reaching here, but its something you can try at least. Pull the plug off the oil level sensor and put a jumper wire in the plug. With it in there, try to start the engine and see if you get a different result.

 

99-2door,
Please tell me what you think is going on when I pull the plug off the oil level sensor and put a jumper into the plug?

I tried it just now and my engine sputtered, caught, fired up and ran. I kept giving it gas for about 15 seconds and it kept running. I let off of the gas pedal and it idled for about 1 second and then died.

It was the most amazing thing I have heard in my garage in the past 3 years.

On your previous post, yes, I mean the security relearn procedure. I know that fuel is being injected when I turn on the key, but then the engine would run a little bit every time I do the 10 minute part of the engine crank cycle. It does it only on the 4th try. This may not be an issue anymore if the oil level sensor is the problem.

By the way, on this engine, I did change the oil pan and oil level sensor from the 2007 silverado to ones from an F-body. I also added a mechanical oil thermostat valve and remote oil cooler (Lingenfelter). I don't think the oil thermostat and remote oil cooler play a part in my problems at this point.

 

oil level sensor won't do this. 50+ vortec 5.3/6.0 harnesses I've modified I remove oil level plug on every one of them.

the 3 ignition cycle for theft relearn is so the PCM will relearn the password that the BCM sends it via class two data. If this is a swap, which I assume, you probably don't have a BCM, any results from the key cycling will be purely coincidence

maybe pcm is programmed for flex fuel injectors and it has standard injectors in the motor..this would cause a very small pulse width??? would cause VERY LEAN condition, might barely run???

whats the 8 digit part# on your fuel injectors. Is the connector for the injectors square or more rectangle (with rounded corners)

 

Busta,
I guess my joy was short lived. I can't start the engine again.

Yes, this is a swap and I don't have the BCM. I don't want to install a BCM if I don't have to. I've heard others with their swaps working without the BCM.

I have flex fuel injectors installed (They're the ones with the rectangular connectors and rounded ends. They're brand new.) But, one thing I've noticed is that my engine VIN and my PCM VIN are different. I can't believe I've just noticed this.

This is the VIN that was on the engine tag when it was shipped to me: 1GCEK19Z77Z184883

This is the VIN that is on the PCM (I've never messed with it. I just found it on HPTuners.):
1GCEK19Z67Z207165

Part Number for my injectors are: GM #12580426.

Maybe the pcm is programmed for normal injectors while my setup has the flexfuel ones? How do I find out? I have HPTuners.

 

You could post your .hpt...

or look in Engine > Fuel Control > General > [Flow Rate vs. KPA]

whats the value in the far left cell?

You can right click on the table, and go down to Units, and change between lb/hr and g/sec. Stock NON Flex Fuel injectors will be 24.49 lb

Flex Fuel injectors would show about 35.4 lb in the first cell on the left.

The injector part# you gave SHOULD be correct for flex injectors. they should look like this:

 

Busta,
My injectors do look like that. I've been trying to crank the engine a few times today after the miraculous start and no dice.
I checked the spark out to the plugs using my timing light and I wasn't getting the timing light to light this time. So, I'm assuming that I have fouled plugs at the moment. I'm going to pull them out tonight and soak them in SeaFoam to get the muck off of them and plug them back in tomorrow.

I do have 35.41 in that cell when I looked in HPTuners. I guess that means that my PCM is probably from a flexfuel vehicle. I haven't tried to mess with any of the other tables at all, so I am hoping that all of the other values would be consistent with a stock engine from the factory. (I hope.)

 

that reminds me..on two occasions I have come across these engines that completely fouled out the plugs. One was a buddy of mine's 1950 dodge with a 5.3L in it..it was last winter..he'd go out start it 2-3 minutes at a time..rev the crap out of it and shut it off...one day he went out there and tried to start it and it just cranked and cranked..I checked a few things, then pulled plugs...wet...changed them and never had a problem again.

2nd was a guy in Canada I did a program for him. he to some how fouled all the plugs...changed plugs, fired right up..

 

The 20 kPA reading is a problem for sure. It should be around 100 or so with key on. Has this been fixed? More than likely this is a wire pinned to the wrong spot on the PCM. I'd go back and check these. What intake/MAP are you running?

I'm not up on the DBW stuff, but 18% TPS at key on doesn't sound right to me. I'd look into that, but like I said I don't work with DBW stuff so I could be wrong there. Just seems odd to me is all.

 

Jrmotorworks, I am running a completely stock Gen III L59 engine from a 2007 silverado. So, I guess it's the truck version of the intake. I went out to the truck and pulled the MAP sensor.

On the MAP CONNECTOR, I tested the wires with a multimeter. I do get the 5V (Gray wire) and ground (from ORG/BLK wire). The signal (Green wire) can't be measured without the MAP installed.

I traced the 3 wires going to the PCM and they look like they are in the right place on the PCM.
5V Gray wire - to C1.48 (Blue PCM connector, pin 48)
GND ORG/BLK wire - to C1.54 (Blue PCM connector, pin 54)
Signal Green wire - to C2.32 (Green PCM connector, pin 32)

So maybe my MAP sensor is bad? I will go to the parts place and pick one up. The sensor has some number: 09359409. There's also a 5355 number on it. The GM dealer should know exactly what I'm looking for.

Update in a couple of hours. (I really feel like I'm getting somewhere. Thanks guys!)

 

So, it hasn't been a couple of hours yet, but I am getting excited that you guys helped me find at least another issue on my problem.

Let me know if this is correct. When trying to test the actual MAP sensor, I just need to ohm out the contacts.

I checked the resistance between signal wire and ground. I get 218 ohms.
I applied vacuum to the port and checked resistance again. I get 218 ohms.

At least to me, I would think that the resistance should change with different amounts of vacuum on the MAP sensor. So it's broken?

Update later.

 

Ok guys. An extremely big thank you to everyone that has helped me diagnose this problem. I really couldn't have done it without all of you. This project has been a 3 year long labor of love and I've spent about a year debugging and redoing stuff and trying to figure out why this engine would not work for me.

The MAP sensor was stuck and not giving proper reading during cranking. The fuel injectors were fooled into thinking that they needed less fuel spray to run because of the MAP reading. Therefore, I never had enough fuel to crank the engine over and start. And the sensor had failed, but had failed within the normal range of values that the sensor works in. Therefore, it never threw a code to my PCM.

Now let me tell you what I am building. It's an expedition vehicle that I hope to take with me on all of my travels in North and South America. And possibly when I take that once in a lifetime trip to Africa, I'll bring this truck.

Here's what it is:
1987 Toyota Land Cruiser
5.3L Gen III Vortec Flexfuel engine
H55F 5-speed manual transmission
3.73 Gearing
Galvanized and powdercoated frame, fender, small pieces
New bolts on over 1/2 of the truck
Custom power steering cooler
Custom remote oil cooler
Custom Fog lights
Custom Rock lights
Alarm system with full lighting control, door locks (and eventually remote start)
Upgraded waterproof fuseblocks and relays
Upgraded electrical wiring all the way around the vehicle
TV
Wi-Fi long range antenna
GPS Navigation
Sleeping quarters (with extra storage and lighting in the sleeping area)
33" tires
Bull Bar
Roof rack
That's all I can remember for now! I hope to get it printed in the Toyota Trails magazine along with printing a manual for others to do this 5.3L swap.

Once again, thanks so much for all the help everyone!!!

Here's a little teaser of the project right before I started:

 

Before I started. Who would rip apart a perfectly good vehicle??

 

So I guess it started and runs now?

 

Yes, the engine starts.

Notes:
I am running a manual transmission and I don't need the C1.75 wire to start the vehicle. It is the IGN0 signal that is supposed to have power during ACCY/IGN/CRANK.

I also removed the 4 wires that go to the PRNDL unit and tells the PCM whether the vehicle is in park, D2, D4, etc. I just set the PRNDL equipped box to NONE in HPTUNERS VCMEDITOR.

FastKat, you have been especially helpful throughout this. My truck had literally sat in my garage for almost a year because of the frustration of not being able to start the engine.

Thank you so much for your help! I will definitely be looking to share everything that I've learned here on the board.

Also, it seems as though there is a need for people to be able to use different accelerator pedals with diffferent TACs and throttle bodies. I'm looking at building a device that can adapt to the different pedals out there. So that we are not stuck using certain pedals just because GM doesn't want to standardize the pedal signals on all of their vehicles.