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pancake · 04-02-2009, 10:42 AM

Hi everyone and thanks for all the great information. I am getting ready to convert my 4x4 rig to TBI and this thread is helping a lot. I have a few questions for you guys. I hope this is ok, I don't want to hijack the thread.

A little about the rig the TBI is going in:
78 blazer with a 350c.i. engine. I pulled the engine from a junk yard with no heads and rebuilt it. The rebuild is pretty much stock except a mid R/V cam and headers. I think the block was fuel injected before, therer is no cut out for a mechanical fuel pump. The heads I put on the block are not off a TBI truck and I know I will have to re-work the two inner intake holes to align with the heads. The tranny is a manual (SM 465) and a NP 205 T/C. This is a trail rig and will only see the road driving from the camp site to the trail head and will be on the trailer the rest of the time. I am thinking of putting a TH400 in this summer with a doubler.

I will be buying a used TBI setup. Should I get a pre 92 or will anyone work? I think Iwill buy a new aftermarket wiring harness from painless or Howell. Do I need to order anything specific for the harness?

Now for the TBI conversion questions:
1) The nuteral safty switch is re-wired so I can start the truck in gear if I need to. Do I just ground the N/S switch? Is it wire B-10? What do I do with the wire if I decide to go to the TH400?

2) After reading about the VSS I will be putting one on the conversion. The VSS conects top the tranny or t-case? Where can I get a cheap one? If I put a TH400 in will I need to change the VSS? The TH400 will have a manual valve body.

3) Where do I put the knock sensor?

4) Where I put the collant temp sensor?

5) I do not have A/C but would like to use the wire from the ECM to bost idel when I need to use the winch. Any sugestions how I would do this? Put in a toggel switch?

6) Which ECM should I look for? Serial #? and will I have to get it re-programed....new PROM?

7) I have a plastic fuel cell in the rig now. I might go to a stock fuel tank with the pump in it in the future. What external pump should I get to ust the fuel cell? Do you have a part number? Do I need a fuel regulator or is this built into the TBI? I do need a return line right?

7) I have also read about a charcoal canister? Do i need one?

Sorry for all the questions but I would like to do this right and you guys seem to know you are talking about. This is the best site I have found for TBI conversion information.

Thank you in advance for the help!!

04-02-2009, 10:42 AM	#136
pancake Registered User Join Date: Apr 2009 Location: Arvada, Colorado Posts: 84	Re: Tbi swap build thread Hi everyone and thanks for all the great information. I am getting ready to convert my 4x4 rig to TBI and this thread is helping a lot. I have a few questions for you guys. I hope this is ok, I don't want to hijack the thread. A little about the rig the TBI is going in: 78 blazer with a 350c.i. engine. I pulled the engine from a junk yard with no heads and rebuilt it. The rebuild is pretty much stock except a mid R/V cam and headers. I think the block was fuel injected before, therer is no cut out for a mechanical fuel pump. The heads I put on the block are not off a TBI truck and I know I will have to re-work the two inner intake holes to align with the heads. The tranny is a manual (SM 465) and a NP 205 T/C. This is a trail rig and will only see the road driving from the camp site to the trail head and will be on the trailer the rest of the time. I am thinking of putting a TH400 in this summer with a doubler. I will be buying a used TBI setup. Should I get a pre 92 or will anyone work? I think Iwill buy a new aftermarket wiring harness from painless or Howell. Do I need to order anything specific for the harness? Now for the TBI conversion questions: 1) The nuteral safty switch is re-wired so I can start the truck in gear if I need to. Do I just ground the N/S switch? Is it wire B-10? What do I do with the wire if I decide to go to the TH400? 2) After reading about the VSS I will be putting one on the conversion. The VSS conects top the tranny or t-case? Where can I get a cheap one? If I put a TH400 in will I need to change the VSS? The TH400 will have a manual valve body. 3) Where do I put the knock sensor? 4) Where I put the collant temp sensor? 5) I do not have A/C but would like to use the wire from the ECM to bost idel when I need to use the winch. Any sugestions how I would do this? Put in a toggel switch? 6) Which ECM should I look for? Serial #? and will I have to get it re-programed....new PROM? 7) I have a plastic fuel cell in the rig now. I might go to a stock fuel tank with the pump in it in the future. What external pump should I get to ust the fuel cell? Do you have a part number? Do I need a fuel regulator or is this built into the TBI? I do need a return line right? 7) I have also read about a charcoal canister? Do i need one? Sorry for all the questions but I would like to do this right and you guys seem to know you are talking about. This is the best site I have found for TBI conversion information. Thank you in advance for the help!! Last edited by pancake; 04-02-2009 at 10:46 AM.