(DIESEL) swapping my 95 S-vin for an F-vin

[DieselDetroit]

Hey boys,

So this is a diesel specific question, hopefully some members can chime. For those of you who know your diesels, here it goes!

Vehicle:
95 ECSB Silverado
6 lug 'light duty' diesel, 6.5 turbo
3/4 ton 4x4 with an S-vin motor
4L80E

I am wanting to convert to an F-vin engine. I have my vacuum pump removed and I have a mechanical waste gate, as opposed to the vacuum powered one

I have an intake manifold from an F-vin truck as well as the PCM. I am currently getting a code when in Drive or Reverse (no codes in park or neutral) since I obviously ripped out my whole vacuum system, which is to be expected

My question are:

1. With the new PCM, I am still getting the codes in drive or park. I was told I have to re-flash for my current application? Does this make sense? The PCM is out of a 3/4 heavy duty diesel (F-vin) with a 4L80E.

2. Do I need to unplug my three vacuum solenoids and the BAR sensor or leave them plugged in with the new PCM? Does it look for them or not? My guess is yes, since the F-vins didn't have them. I have heard mixed opinions, the most popular is leaving the BAR sensor plugged in, and of the three vacuum solenoids, the one closest to the firewall leaving it plugged in.


Again, this is a super specific question. If any members need more info, please feel free to ask!

Thanks




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[great white]

What year is the new PCM from?

What are the codes its giving your?

I'm more of an obdii guy, but there are several calibration options for just the 5 odd years of obdii. If you put the wrong year PCM in the wrong year truck it won't run as the calibration files are different.

Obdi has a removable "chip" that holds the calibration. This is all you need to change vice the entire PCM. Obdii has an on board flashable chip so you have to either program it in situ (which I do with Tunercats II) or you have to change out the entire PCM.

I would suggest you get a hold of someone like bill heath at heath diesel and buy a new calibration (ie: chip) that will both deal with the intake manifold swap and wake the truck up a bit. Its just a drop in chip like OEM.

He can set it up so you can remove all the vacuum lines and baro sensors except for the boost sensor. You'll end up with what is essentially an L65 engine except it will be a bit "perkier" than a regular L65.

I do my own work, but my L65 is doing about (crank estimate) 300 hp/500 lbft.

The rear wheel dyno numbers are in my Sig line.

That reflects a bit more work than just recalibration, but a good "tune" can get you right around 180-200 rwhp.

 

[DieselDetroit]

Both PCMs are OBD1

I didn't check the codes with the new PCM, but I assumed they were still the same EGR codes since the MIL turned on in drive/reverse, the same as the previous PCM.

I should have checked the codes tho,


Another thing I heard was keeping my PCM and just switching the internal EPROMs?

I will pull the codes again tonight or tomorrow to be sure, but I am confident they are EGR related since park/neutral was good, it behaved as if the PCMs didn't get swapped

 

[great white]

Both PCMs are OBD1

I didn't check the codes with the new PCM, but I assumed they were still the same EGR codes since the MIL turned on in drive/reverse, the same as the previous PCM.

I should have checked the codes tho,


Another thing I heard was keeping my PCM and just switching the internal EPROMs?

I will pull the codes again tonight or tomorrow to be sure, but I am confident they are EGR related since park/neutral was good, it behaved as if the PCMs didn't get swapped

I was editing while you were typing. Most of your questions are answered above.

 

[DieselDetroit]

What year is the new PCM from?

What are the codes its giving your?

I'm more of an obdii guy, but there are several calibration options for just the 5 odd years of obdii. If you put the wrong year PCM in the wrong year truck it won't run as the calibration files are different.

Obdi has a removable "chip" that holds the calibration. This is all you need to change vice the entire PCM. Obdii has an on board flashable chip so you have to either program it in situ (which I do with Tunercats II) or you have to change out the entire PCM.

I would suggest you get a hold of someone like bill heath at heath diesel and buy a new calibration (ie: chip) that will both deal with the intake manifold swap and wake the truck up a bit. Its just a drop in chip like OEM.

He can set it up so you can remove all the vacuum lines and baro sensors except for the boost sensor. You'll end up with what is essentially an L65 engine except it will be a bit "perkier" than a regular L65.

I do my own work, but my L65 is doing about (crank estimate) 300 hp/500 lbft.

The rear wheel dyno numbers are in my Sig line.

Quick question, I don't need to put the entire PCM from the other F-vin in my vehicle, just the blue chip? That way I can continue to use my PCM?

Not only do I want the MIL to go away, but I'd like to have it as factory as possible. I will definitely consider Heath as a backup plan, as I have had great experience with them, but I'd prefer to work with the items I have already purchased as I am extremely poor right now.

Above you said 'except the boost sensor', I have replaced my waste gate solenoid with a mechanical one, so this statement does not apply?

Thanks for all your tips! I am not a huge fan of modifying factory specs as I am more of a maintenance guy at this moment, but things might change! My engine is tired and I'd like to keep her running with stock numbers.


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[great white]

Quick question, I don't need to put the entire PCM from the other F-vin in my vehicle, just the blue chip? That way I can continue to use my PCM?

Not only do I want the MIL to go away, but I'd like to have it as factory as possible. I will definitely consider Heath as a backup plan, as I have had great experience with them, but I'd prefer to work with the items I have already purchased as I am extremely poor right now.

Above you said 'except the boost sensor', I have replaced my waste gate solenoid with a mechanical one, so this statement does not apply?

Thanks for all your tips! I am not a huge fan of modifying factory specs as I am more of a maintenance guy at this moment, but things might change! My engine is tired and I'd like to keep her running with stock numbers.


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Yup, just the chip needs to be swapped.

The PCM calibration needs to know what the manifold pressure is to properly schedule the fuel. Hense, you need to boost sensor that is on the intake manifold. Looks just like a map sensor, except it is a 2 bar boost sensor.

Your barometric sensor is the same, but it is a 1 bar sensor.

Technically, they're both map sensors, just different ranges.

215,000 is no spring chicken. But its not next to death either(if in good shape). 300,000-350,000 is time to start getting nervous and saving for a new engine on a 6.5

When were the injectors last changed?

When was the harmonic damper last checked?

Both can wipe out a 6.5 in pretty short order if they go south...

 

[DieselDetroit]

Yup, just the chip needs to be swapped.

The PCM calibration needs to know what the manifold pressure is to properly schedule the fuel. Hense, you need to boost sensor that is on the intake manifold. Looks just like a map sensor, except it is a 2 bar boost sensor.

Your barometric sensor is the same, but it is a 1 bar sensor.

Technically, they're both map sensors, just different ranges.

215,000 is no spring chicken. But its not next to death either(if in good shape). 300,000-350,000 is time to start getting nervous and saving for a new engine on a 6.5

When were the injectors last changed?

When was the harmonic damper last checked?

Both can wipe out a 6.5 in pretty short order if they go south...

Ok so I'll swap THe EPROM chip, unplug the three vacuum sensors and the one Baro sensor, but leave the boost sensor on the IM plugged in.

I haven't swapped intake manifolds yet. This is still on the to-do list.

Any comments on the PCM relearn? Not required if I'm only swapping proms?

To answer your questions

1. (injectors) not sure..... It has been a while for sure

2. (Damper) I have checked underneath, she looks good, doesn't wobble when I drive. My eye is pretty untrained so I'm not sure exactly what to look for......

One question tho, what information is stored on the EPROM chip? I'm assuming it knows it's an L65, but what else?


Thanks fellas!


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[great white]

Ok so I'll swap THe EPROM chip, unplug the three vacuum sensors and the one Baro sensor, but leave the boost sensor on the IM plugged in.

I haven't swapped intake manifolds yet. This is still on the to-do list.

Any comments on the PCM relearn? Not required if I'm only swapping proms?

To answer your questions

1. (injectors) not sure..... It has been a while for sure

2. (Damper) I have checked underneath, she looks good, doesn't wobble when I drive. My eye is pretty untrained so I'm not sure exactly what to look for......

One question tho, what information is stored on the EPROM chip? I'm assuming it knows it's an L65, but what else?


Thanks fellas!


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Relearn is for vats equipped trucks. If memory serves, that wasn't an option in 95. Now if you're talking tdco relean: yup, should be done. Cold restart process is also a good idea, it allows the PCM to do a module query before kicking it over. Basically, on for 1 minute, off for one minute, then on, run through a glow cycle and then start. Not required, but a good idea.

The chip holds the calibration data.

Basically, all the look up tables and switches. Fuel, boost, transmission shifting, timing, hot modes, cold modes, etc. Switches are things like 4x4, standard/auto, L56/L65, etc.

 

[Scrufdog]

go to radio shack and pick up some 50 ohm 10 watt resistors. install them across the hot wire and signal wire (3 pin connector), or the hot and ground (2 pin connector). This emulates a control coil being installed. Leave the baro installed, it wont effect anything much. I've used this fooler trick on many vehicles, both obd1 and 2, including my 97 Vin F when i installed a manual boost control. Also used this trick once when converting a Dakota from automatic to manual transmission.

A few bucks may solve your problems. When I did this to my 97 it worked great for a few months on the stock pcm. I left it in there with the Heath Diesel pcm and still no problems.

Pull your codes too

 

[DieselDetroit]

Relearn is for vats equipped trucks. If memory serves, that wasn't an option in 95. Now if you're talking tdco relean: yup, should be done. Cold restart process is also a good idea, it allows the PCM to do a module query before kicking it over. Basically, on for 1 minute, off for one minute, then on, run through a glow cycle and then start. Not required, but a good idea.

The chip holds the calibration data.

Basically, all the look up tables and switches. Fuel, boost, transmission shifting, timing, hot modes, cold modes, etc. Switches are things like 4x4, standard/auto, L56/L65, etc.

Not sure what vats is but I guess I don't care if it isn't equipped

1) how do you do TDCO relearn?

2) cold restart relearn - do you do this each time before starting the vehicle?

Also, based on what you have told me, what would the downfall be if I kept my PCM from a non F-vin vehicle? Incorrect fuel and boost?

Thanks so much for the info. I love this forum

go to radio shack and pick up some 50 ohm 10 watt resistors. install them across the hot wire and signal wire (3 pin connector), or the hot and ground (2 pin connector). This emulates a control coil being installed. Leave the baro installed, it wont effect anything much. I've used this fooler trick on many vehicles, both obd1 and 2, including my 97 Vin F when i installed a manual boost control. Also used this trick once when converting a Dakota from automatic to manual transmission.

A few bucks may solve your problems. When I did this to my 97 it worked great for a few months on the stock pcm. I left it in there with the Heath Diesel pcm and still no problems.

Pull your codes too

I will pull my codes. Also, the method above, is that for manual boost? I do not have manual boost, I do have a mechanical waste gate solenoid controller but that's it, it is just a replacement to the vacuum system


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