Hmmm, got to thinking, would this work (re: 350tbi>454tbi swap)

[fortcollinsram]

The 454 I picked up is out of a 1992 CK3500 4x4...I got the ecm and wiring harness with it...the wiring harness fo rthe 454 is *slightly* different than what is currently in my 350tbi blazer...The main differences are in the connectors to the sensors on the TB...Now could I put the 454 in the blazer with the current wiring harness and just swpa connectors that are diffent and then just swap the chips in the ecm instead of swapping the entire ecm? I am concerned that if the 454 ecm has a few extra sensors than are contained on my 350tbi harness, it might go on the blink...So what systems and sensors are mandatory for a TBI system? so far I have the following:

-MAP sensor
-Knock Sensor
-ESC
-EGR system
-TPS sensor
-IAC sensor
-Temp. sensor
-oil press. sensor


What else...I would really like to keep me existing wiring harness in the truck b/c I am an electrical moron and I really don't want to do the extra work... Thanks for the help gang...

Chris

 

[gtkustoms]

Chris
If you "feel" /forums/images/graemlins/confused.giflike it can't be done then maybe we could work out a trade for my d60f and your BB /forums/images/graemlins/rotfl.gif

Travis

 

[fortcollinsram]

nice try Travis...I GONNA make the BBC work...I just gotta figure out what method will lead to the least down-time for the truck and the least work for me and still work out alright in the end...About the D60, are you willing to separate it from the 14bff? Also where are the axles? Thanks Man...Chris

 

[gtkustoms]

Chris
yeah i will seperate them
they are in SD but i am going up there next week so let me know if you want it i can bring it to your door step /forums/images/graemlins/grin.gif

Travis

 

[Chris Demartini]

<font color="blue">What extra sensors does the 454 have? Get good diagrams (not those crappy helms/chiltons ones) and ECM pinouts for each, then sit down and figure it out.

 

[fortcollinsram]

The BBC has an extra temp sensor in the passenger side head (it is an aux. temp activate switch). There is also a little box deal on the right side of the intake in front of the map sensor...I have no clue what the hell it is...It has a vacuum tube from the TB and a little cover that says "air filter" on it...Where can I find a decent diagram of the ECM pinouts? Helms, Inc. doesn't even have any manuals available for my 1987 K5 but they did have the 3000+ page service manual available for the 1992 CK3500 for $120...What about that www.alldatadiy.com ? Has anybody used that resource? Thanks again....

chris

 

[Chris Demartini]

<font color="blue">I never tried the alldatadiy, (I have access to the full version) but it looks like it might have what you need. I have seen some good diagrams on here, I just dont know where they came from

 

[Kyle89K5]

Easiest way to check I think would be to pull the ecm down from your truck now and see what the number is on it. If it doesn't match the number on the one from the 454, then no. The one you have is prb. something like 1227747. It doesn't take 2 minutes to pull the computer down and look. If'n it were me, I would not try and reuse my 350 harness and ECM, but that is for two reasons. 1. I've spent the last 4 months going over every wire and sensor on my truck, I know where they are, I could route another harness pretty easylike. 2. I spent the last 4 months going over every wire and sesor on my truck do what turned out to be an improperlly spec'd cam from the machine shop. That little booboo caused the truck to run rich and in turn, lean out the oil. Now I've got a spun main bearing in a motor with less than 500 miles on it.

My advice, just use the stuff that you KNOW works.

HTH

 

[fortcollinsram]

I know fo r a fact that the number's are different as they are differnet computers... the 454 ecm is an 1228747 ans the 350 is a 1227747, like you said...This is b/c they have different PROM's. I think I am going to get a diagram and figure out the ecm pin-out on the 454's ecm...Then I will look at the pin-out configuration (if I can find the damn thing) for the 350'ecm...If they match, which they should according the the gang on www.454ss.com , I will swap the connectors in my current harness that need changed and I will use the entire 454 ecm...

Chris

 

[jmd]

If you have the same ECM, use the 454 PROM, use the 454 harness, and if the 5.7L throttle body doesn't mate up to the harness, use the 7.4L throttle body. I'm sure the dash wiring will be simple; probably plug &amp; play w/ the harness to dash connections.

 

[fortcollinsram]

Okay, I found a few diagrams, and the Pin-Out for the 350 ecm is THE SAME as the Pin-Out for the 454 ECM /forums/images/graemlins/thumb.gif...Therefore, the the 350 harness will work on the 454 once I get the connectors for the 454 TB onto the 350 harness...Oh and what the hell is the EVRV valve...it stands for Electronic Vacuume Regulator valve and is is some how connected with the EGR but how? And where the hell is it on a TBI 350...

Chris

 

[jmd]

Understood. But if the 454 harness mates right up to your dash, you'll have an easier time just throwing that harness into your truck... assuming they didn't integrate the front end harnesses (lighting, ECM) together. Is the 454 harness you have just for the ECM? If so, why splice two into one, when you already have one that will work perfectly?

 

[jmd]

The EVRV valve may do the same job as an EGR solenoid on earlier passenger cars. My TPI and my computer Q-jet cars have an EGR sol. ... Is it fed vac. and then has a line going to the EGR valve? If so, that's it.