Chevy & GMC Vans

Hello all,
I know from my days at As.com that someone (well not someone, but somebody) swapped a CSFI 4.3 for a similar V8. Who was it ?? I want some info, opinion on it.


TIA,
Dave

You're probably thinking of Bill aka LOCKDOC. He swapped a V8 in a 93 that had the CPI injection system. I was going to do it also in my 95 with a motor from a 95, almost direct swap, only a few wires to swap around.

I'm interested also, as I'm looking to do a similar swap. I've been reading alot at the differtent S-10 sites, full size chevy, third gen and others. What I've read so far is that even though the CSFI system is not the greatest it can get a motor over 300 HP. One even claiming 400HP I have my doubts about that, but I also would like to believe it just because that would fit into my plans nicely. From what I've read the Vortec V6 to Vortec V8 swap is one of the easiest. It's just a matter of adding the wires for the injectors, and changing out the V6 injector connector to a V8 connector. Besides the obvious things like motor mounts, probably a better radiator, trim the shroud, reprogram the VCM, and change the exhaust. From what I read all the sensors and connectors match up, same with the accessories, throttle valve(V6 same as V8), and air ducting. From what I've read you can use any year engine('96-'01), use your V6 wiring harrness with the modifications, and your V6 VCM reprogramed. I was reading this at a S-10 site, but it probably holds true for our vehicles as well, if not I would appreciate being set straight. Thanks.

Well, that's what I was hoping for. Guess I'll have to figure out which year to get the donor from and get the wiring schematics for both.

Here's a couple of good links on the subject.
http://forums.s-series.org/viewtopic.php?t=34039
http://forums.s-series.org/viewtopic.php?t=19845

I did the leg work on that a while back with alex for my 98. From what I gathered talking to him he was pretty sure if a same year 5.7 is used that came from a truck with the same tranny (4L60-E) and you got the ECM or even just the prom chip from it, it should just be a matter of running 2 more injector wires and extending 2 others so they will reach the front of the intake as long as the ecm is compatible. I'm not to sure on retainment of the dash functions and such tho. Otherwise it's just the mounts and the regular stuff.

The year of the V8 doesn't really matter(as long as it's part of the Gen I Vortec Family '96-'01). It's the PCM that you have to worry about. Usually it's best to keep the one thats in the truck(as long as we are talking vortec to vortec) especially on '98 and up becuase of the Pass-Lock anti-theft sysyem. The VCM or PCM uses a EEPROM so there is no chip to replace. If you used a donor computer from the V8 instead of the original you would be best off if the truck is a '96-'97 other wise you would have to send the computer out to get reflashed anyways because of the pass-lock system. So you might as well have the original flashed reguardless of the year especially if any perforance mods where done(cam, heads, porting, or the like) that way it can be programed for that at the same time. That way everything will function as one without compatability issuses as far as gauges or anything else.

bypassing the Passlock system isn't all too hard. Especially if you have access to the key that came with the truck. If not a quick trip to the dealership with the vin and salvage title should net the key or resistance value to just build a permanent bypass. IIRC it's literally just soldering the resistor between the 2 wires in the steering column or directly to the ECM if need be.

Good info. Thanks.

potskie wrote:bypassing the Passlock system isn't all too hard. Especially if you have access to the key that came with the truck. If not a quick trip to the dealership with the vin and salvage title should net the key or resistance value to just build a permanent bypass. IIRC it's literally just soldering the resistor between the 2 wires in the steering column or directly to the ECM if need be.

Yes the PassLock can be bypassed like this, but what you are referring to is Passkey...there is 3 wires in a PassLock system, you just have to use the correct 2.

PassLock - the security is in the lock. Blank, simple key.
PassKey II - the security is in the key. Visible resisted pellet key, # 1 thru 15.
PassKey III - the security is in the key. Transponder in the key head, approx 3 trillion possible transponder values.

I'm glad I have a '97 with none of the above!

v8famvan wrote:

potskie wrote:bypassing the Passlock system isn't all too hard. Especially if you have access to the key that came with the truck. If not a quick trip to the dealership with the vin and salvage title should net the key or resistance value to just build a permanent bypass. IIRC it's literally just soldering the resistor between the 2 wires in the steering column or directly to the ECM if need be.

Yes the PassLock can be bypassed like this, but what you are referring to is Passkey...there is 3 wires in a PassLock system, you just have to use the correct 2.

PassLock - the security is in the lock. Blank, simple key.
PassKey II - the security is in the key. Visible resisted pellet key, # 1 thru 15.
PassKey III - the security is in the key. Transponder in the key head, approx 3 trillion possible transponder values.

Hey James, glad to see you're stil hangin around!!!

Here ya guys go. Bill did have some pics on the wiring changes he made too.
viewtopic.php?f=8&t=188

BLAZER wrote:Here ya guys go. Bill did have some pics on the wiring changes he made too.
viewtopic.php?f=8&t=188

That's a good thread, but it's not what the original post was about "Vortec 4.3 to Vortec V8". That post is about a 4.3 CPI(not CSFI) to V8 TBI. It's not the same thing.

v8famvan wrote:

potskie wrote:bypassing the Passlock system isn't all too hard. Especially if you have access to the key that came with the truck. If not a quick trip to the dealership with the vin and salvage title should net the key or resistance value to just build a permanent bypass. IIRC it's literally just soldering the resistor between the 2 wires in the steering column or directly to the ECM if need be.

Yes the PassLock can be bypassed like this, but what you are referring to is Passkey...there is 3 wires in a PassLock system, you just have to use the correct 2.

PassLock - the security is in the lock. Blank, simple key.
PassKey II - the security is in the key. Visible resisted pellet key, # 1 thru 15.
PassKey III - the security is in the key. Transponder in the key head, approx 3 trillion possible transponder values.

Either way as long as it isn't passkey III you can just buy the $25.00 bypass that you need so you can use remote starters.
See em all the time for GM VATs, Passkey, Passlock I, Passlock II.

With things being like that with the VAT the best thing to do is get the truck running with the swapped PCM from the V8 and get the truck running as good as possible then datalog the truck running in a few different scenerios. Then send off the vehicles original V6 PCM with the datalog info and have it reprogramed for a V8 and more performance with no down time on the truck then just reswap the PCM's. The reason I say this is I think the key to get more power out of the Vortec after performance mods is to have the PCM reprogramed. I'm sure you would get your moneys worth from having a Pro tune it, but I am reading about DIY programing there is just tons of material to know. You can download a demo copy of Jet's DST here http://www.jetchip.com/downloads/DST_Tuner_Setup.zip
It's pretty cool.