Hello all, I am new to this site and I have noticed there are very well knowledgable computer tuners. My application is a little different from the usual discussion. I have an 86' S10 truck, with a crate 3.4L V6 60* motor and a 400 cfm (4.3) GM TBI unit on it. Now I need to make an ECM for it.

A fellow on another forum has given me this info to make a custom tuned ECM. Remember, my app is a 3.4L V6 60* with a 2 bbl TBI. It has a stock "2.8 TBI S10" coil and dizzy.

The ECM I am going to use is a 16197427. It is brand new and is set for a 94' Chev Cargo Van with a 350 TBI. I was told to get the V6 MEMCAL from 94-95 Chevy Astro Van with a 4.3 CPI as it also has the same ecm serv.#.

Then I was told I need to buy a ALDU1&CABL1 combo, a BURN2 Chip Programmer, a G1 Memory Adapter, and a Ostrich2.0 to tune in "Real Time". Then I need to download TunerPro for the windows system.

SO: With all of those tools, a V6 4.3 CPI MEMCAL, and a 16197427 ECM from a 350 TBI, is it possible to build a Tuned ECM for my 3.4V6 TBI system??

Thanks!

 

You may need the specific knock module and knock sensor for the 3.4L.

 

The motor right now has everything the old 86' 2.8 TBI did. Same knock sensor, same knock module, same dizzy setup, same style coil (but now a MSD), same TBI setup (but larger than the original), same MAP sensor, same everything!

It does run on the old 2.8 TBI ECM right now, but I read that the 16197427 is the best for TBI setups. I just need to know if the '427 ecm for a 350TBI and a 4.3 CPI MEMACL/PROM that was in a '427 ECM can can be modified to my 3.4 TBI.

BTW it is a standard 5 speed. I know the '427 is for a E-tranny, but can it be programmed to run a manual??

 

Yes it will work and will be a good upgrade from your old ECM.

The 7427 is a Motorola PCM6. The most common ones are 8625, 6395, and 7427.

Your existing knock module is not needed and will need to be removed. The 7427 has the knock module built into the MEMCAL. The knock sensor/sensors will need to be wired directly into the PCM (check wiring diagrams for details). Your existing knock sensor won't work with the 7427.

Since the knock module is built into the MEMCAL that determines which TBI MEMCAL to use. What you really need is a 2.8 MEMCAL for a 7427, but I don't think that exists. I know that it doesn't up to 1993 and after 1996 GM went to OBDII so one won't exist there. I don't know what ECM or PCM was used in 94 and 95 for the 2.8, if it was still offered.

If you use a 4.3 MEMCAL you will need TWO 93-95 4.3 knock sensors. The 4.3's have one sensor on the side and one sensor at the rear. Each have a different threaded section. You can use either of these that will work where ever you want to mount it, electrically they are the same. The CPI and TBI MEMCAL's may be different in some other ways as well. It would be simpler just to get a common TBI 4.3 MEMCAL and avoid any potential problems there.

If you use a 350 or 305 V8 MEMCAL you will need one 93-95 350 or 305 knock sensor.

Either of these will run the engine with the proper tune. Personally I would pick a TBI one with the closest cylinder bore size to your 3.4L.

With the right options set, the 7427 will work with a manual transmission.

 

No 2.8 had the '7427 unfortunately. Apparently no V8 MEMCAL can be turned into a V6??

I can only find a '7427 V6 MEMCAL in a 94-95 4.3 CPI setup. My motor block has provisions for 2 knock sensors. You say the ECM can be set for a stick tranny.

So the '7427 ECM, with a 94-95 '7427 4.3 CPI MEMCAL, and the two knock sensors, and with lots of tuning, I can make this setup work with my 3.4L V6 TBI??

 

The problem with the V8 memcal is that, although the PCM will still fire the injectors properly for TBI, the timing will be way off as the cylinder count is set to '8'.

If you have prom buring equipment, then pretty much any one will work. You can just simply set the cylinder count, and install the appropriate KS type for the V8 memcal, and go. The only potential issue may be with the filtering, as the 4.3L and 5.0/5.7L are all essentially SBCs, while you have a 60 deg V6. Also, you can only use 1 sensor.

As far as tuning, just the burn1 and g1 adapter will be necessary. Theres not as much need for real time burning if your willing to reburn the chip each time. I even tune my current vortec SFI PCM this way, by just popping the flash chip into a pocket programmer.

Additionally, I dont think the tuning will be excessively hard. Its mainly a matter of setting the proper cyl. volume, setting the right options, and dialing in the VE and SA tables for your engine.

 

Have we confused you yet? Hopefully this will help clear it up some.

V8 MEMCAL's can be used with a V6. It's the tune/bin that gets changed to V6.

Your not limited to MEMCAL's from 7427's, the MEMCAL's from 8625 and 6395 PCM's will work in your 7427.

What I'm recommending is a TBI 305 V8 MEMCAL and knock sensor with a TBI 4.3 tune/bin, converted to manual transmission.

I agree with dimented24x7, the tuning shouldn't be too hard.

 

Thanks for the help so far guys! Its really helping me out as I am just starting out on this stuff.

I am a little confused, but not too bad

Sounds like all I need to do is get the right Tuning tools (looking into moates.net and TunerPro), so I can turn the 350 TBI MEMCAL into a V6 one?, set the proper displacement, and build fuel and timing maps?

Also I need 2 knock sensors, and no Knock sensor module right??

This computer stuff seems so complicated!!

 

With the 350 MEMCAL you need just one knock sensor and no external knock module.

 

OK, I think I'm getting on track here. I think I'll use the 350 TBI ECM and the 350 TBI MEMCAL, and turn it into a V6. I can program the unit to run a manual tranny right?? And what mods do I need to do to run my current speed sensor (runs with mechanical speedo)??

I am looking at getting the Moates APU1 and G1 Adapter.

Thanks for the help so far guys!! Much appreciated!!

 

I don't know about the speed sensor issue. Does your tuck use a DRAC?

 

yes it should have one attached to the ecm

 

If it's got a DRAC then I don't think there will be any problem since it's a manual. Just pin the current ECM VSS signal into F13 and leave F12 empty.

F12 = DRAC Signal for auto transmission control.
F13 = DRAC Signal for engine control.

 

If the DRAC is flat looking box bolted to the ecm, then no I DONT have that. My speed sensor is a fiber-optic light that plugs in the back of the dash and the wires go directly into the ECM.

So what should I do??

 

Theres been a similar discussion going on here:
http://www.fullsizechevy.com/forum/g...n-control.html

Just pin the current ECM VSS signal into F13 and leave F12 empty.