S to F

[Sawtelle 1]

I have a chance to pickup a 95 vin f manifold , plenum, and computer. But the 95 is a standard and mine is vin s and auto. Would I need a different chip or is this not going to work?

 

[chi2]

Why would you want to put a chip from a truck with a manual transmission into an automatic? You can swap the intakes without installing the chip from the F truck. Your truck will throw a code or two b/c your EGR is gone.

In my 94 (in sig) I switched my S intake (upper and lower) to an F intake, while keeping my stock programming, and the truck runs fine. I do have codes for the EGR, but that is b/c I no longer have one.. ):h

If you are worried about seeing the codes, you can buy a stock F chip (for an automatic). IIRC, they are not that expensive.

I have a chance to pickup a 95 vin f manifold , plenum, and computer. But the 95 is a standard and mine is vin s and auto. Would I need a different chip or is this not going to work?

 

[Sawtelle 1]

I was thinking with the F computor I could do away with all EGR parts solonoids, vacume lines, etc

 

[gmctd]

If "F" PCM is for manual trans, which does not have the 4L80E routines in rom, neither the eprom or PCM will work in your system with the automatic - some '94 "S" automatics were the 4L60E, so you need to make sure your version is 4L80E or the auto "F" upgrade won't work, as the 2500\3500 had the 4L80E - '94 was the last year for the 4L60E's behind the 1500 Diesel engine, both 2wd and 4wd - if you stick an "F" eprom in the "S" PCM, that eliminates the "S" emissions

 

[Sawtelle 1]

It is a 4l80e. I wasnt sure if the difference was in the chip or the computor. So will be getting the manifold and plenum. Thanks for the info.

 

[Turbine Doc]

on OBD-Is you rechip, OBD-IIs you reflash/replace puter

 

[Bullseye240]

You can simply bolt your EGR on top of your F-plenum and not throw any codes. Also be sure to use the F-code intake gaskets with the built in block off plates. I used them on mine with an F plenum and S lower manifold and have no codes and the truck runs fine.

 

[Turbine Doc]

works on OBD-I, not on OBD-II

II's monitor vac applied via baro sensor, so to convert S to F on those you need to keep sensors active, but you can blank off EGR ports with blank off shim between EGR valve & upper plenum, and let EGR valve "cycle", F gaskets are short term fix, some have blown thru over time when used with S intakes, better to use steel freeze plug in center tower of S lower, or shim the valve as described above.

 

[GM Guy]

Where is this junker truck and is the manual tranny still in it?

 

[Sawtelle 1]

The truck took a hard right and tried to play bigfoot on several lava rocks. The transfercase was ripped off, bellhousing broken. and front diff is in the oilpan.
So mine being OBD-1 the chip change would take care of codes and then I can clean up the engine compartment,

 

[Turbine Doc]

Just plugging EGR vac line on OBD-I should keep from coding, and stop flow if EGR valve seat is still good, if seat is bad you still have hot gas possibly flowing, so you will need some blocking mechanism(freeze plug-F gasket set with blocking plate, or shim under EGR valve) best is F intake complete, often forgotten though is "mystery gasket" that goes between upper & lower S intake (1 time use, replace if upper is removed, or if rots & bad EGR gas flows continually) chip to F chip will get more fuel and permanent eliminate any code potential

 

[gmctd]

You might take a second look at the engine in that carcass for posteriority's sake - could be a good block spare for when the ole cookie crumbles - also wiring harnesses, inst panel, etc