Dabomb's 1985 Jimmy - Rust Repair/Floor Replacement/Upgrades: TPI Swap

[dabomb6608]

Amen to that. So ready for the warmer weather to start rolling in. Looking at the extended forecast it is looking like late next week and next weekend will be a lot warmer. High 40's low 50'S. Of course it decides to get warm during spring break when I'm going to be out of the country for a week. I leave next Saturday.

 

[dabomb6608]

Progress has been slim to none. Got back from being out of country this past Saturday. Was a fantastic get-away. Unfortunately everything decided to go downhill it seems like once I returned...My daily driver (96' Ford Taurus) decided to start acting up this week. Missing really bad/brakes acting funny.

So Tuesday night I decided to look at the brakes. Bled the front driver side since that one wasn't even functioning. It helped get rid of the slushy brakes. Took it out for a test drive to see how well they work....worked fantastic until both rear hard lines decided to bust. Guess I was being a little to hard on the severely rusted lines to hold. Thankfully I was a few miles from home on back roads.

Wouldn't you know it, you can't order pre-bent lines for them! So been driving the Trans Am all week. Which I hate doing because the transmission is on its last breath. Not to mention it needs further tuning in a bad way. But can't do that till after the exhaust leak is fixed which is waiting to be fixed once the engine gets pulled for the new transmission...supposed to warm up this weekend so the motorcycle will be getting pulled out for duty.

In other news....my TPI harness has arrived along with a new TBI sending unit. Now I need to order a new tank and sit down with this harness and get it prep'd for stand alone usage. Once the Taurus is fixed I will be turning my attention to the truck hopefully!

 

[dabomb6608]

Its go time for the TPI Project! I've got the Taurus back in daily driver mode so it is time to enjoy the warmer weather and get out in the garage and get to business!

I've got the TPI harness laying on the tailgate ready for me to start prepping it for stand alone use. Have the correct fuel pump on the way to replace the new stock TBI pump that came in my new sending unit. Plan on using the existing tank (for now) and then eventually if it becomes a serious problem I will upgrade to the correct tank. It isn't a huge deal taking these tanks out of the truck. Especially compared to my Trans Am...

Plan of attack is getting the wiring started tonight. Work on that through the week and once it is ready for transplant into the truck I will begin that process. I hope to have only a handful of extra connections that will need to be made to the truck system. Just like any stand alone harness would come. I will also be converting the MAF (86'-89') harness that I have to MAP style for use with the same kind of EBL ECM I have in my Trans Am. That way any tuning I need done can be accomplished easily.

Once wiring is out of the way I will work on the fuel system. Pull the tank, get new sending unit installed, upgrade hoses to high pressure rated hose, run the extra return line, and figure out how I will get it all connected at the rail.

Then comes the "easier" stuff like installing the intake/fuel rails/injectors, acquiring and installing the various sensors I don't already have with my spare TPI setup, and final finishing work to make it all come together.

That should keep me busy for the next coming weeks. It begins at 6 o'clock tonight!

 

[jekquistk5]

Its go time for the TPI Project! I've got the Taurus back in daily driver mode so it is time to enjoy the warmer weather and get out in the garage and get to business!

I've got the TPI harness laying on the tailgate ready for me to start prepping it for stand alone use. Have the correct fuel pump on the way to replace the new stock TBI pump that came in my new sending unit. Plan on using the existing tank (for now) and then eventually if it becomes a serious problem I will upgrade to the correct tank. It isn't a huge deal taking these tanks out of the truck. Especially compared to my Trans Am...

Plan of attack is getting the wiring started tonight. Work on that through the week and once it is ready for transplant into the truck I will begin that process. I hope to have only a handful of extra connections that will need to be made to the truck system. Just like any stand alone harness would come. I will also be converting the MAF (86'-89') harness that I have to MAP style for use with the same kind of EBL ECM I have in my Trans Am. That way any tuning I need done can be accomplished easily.

Once wiring is out of the way I will work on the fuel system. Pull the tank, get new sending unit installed, upgrade hoses to high pressure rated hose, run the extra return line, and figure out how I will get it all connected at the rail.

Then comes the "easier" stuff like installing the intake/fuel rails/injectors, acquiring and installing the various sensors I don't already have with my spare TPI setup, and final finishing work to make it all come together.

That should keep me busy for the next coming weeks. It begins at 6 o'clock tonight!

Good luck

 

[dabomb6608]

Wiring...one of my least favorite things to do. So why not dive right in head first!





Started taking apart the stock harness I bought. Removing unnecessary wires as I went along. Things like the cold start/EGR/A.I.R./Charcoal Canister to name a few. Ended up with a small pile of junk wiring hanging out.



That pretty much summed up the removal of any wires I wouldn't be using. Next up, is prepping the ECM connectors for conversion to MAP/EBL Flash use. Need to remove 3 wires and repin 4 wires to different locations. I am assuming that the 3 wires that I remove might have already been removed from when I removed the above wires. If not I will follow them to the other end and permanently remove them so they aren't just folded up into the harness.

With the conversion to MAP I will be able to get rid of a few relays hopefully as well. Along with any remaining MAF wires that aren't used. Two of the wires from the MAF are reused for MAP ground and signal. The remaining wires will be removed.

Once all of that is finished I can move on to the under dash connector. Referred to as the C207 connector in Camaro/Firebirds. It has several wires that won't be used. But has some that will be. Like the check engine light, fuel pump power, ECM ground (one of them), ECM power (again one of them), Gear Select Switch, VSS feed, and TCC Brake Switch. All of those will need to be removed from the connector and then wired into their corresponding locations.

I am unsure of what to do for the Gear Select Switch. My Trans Am is a manual so I didn't need to worry about this when I installed TPI on it. Where (if there even is one) can I find a wire that is closed when the truck is in Park/Neutral and open in all other gears? Is there one somewhere on the column?

For the VSS feed, I think there is one of those heads on the back of my speedometer that has the optic thing for cruise control??? I am "hoping" I can use that....

So that's the plan for tonight. Hope to make more progress. I am ordering a few things to help finish the wiring up. Like new wire loom, heated O2 sensor kit, and a MAP sensor connector.

 

[82355]

I really want to do this to my Blazer.

Martin

 

[dabomb6608]

Another night and more progress on the harness. I got everything but the MAP connector finished for the conversion to the EBL Flash ECM. I cleaned up more of the harness as well. Removing all the MAF relays and their wires. That cleaned up the harness quite nicely.





Once that was done my scrap pile grew even more.



With the conversion done and the main harness finished up it was time to grab my intake to do a rough routing of my wires. I wanted to relocate the TPS/IAC/CTS connectors to run up the harness along the passenger side fuel injector harness. To try and clean up the final outcome. I got them routed and started zip tieing here and there to get it to stay together. Turned out pretty good. I have new wire loom on the way.



Tonight I plan on taking the needed wires out of the C207 connector and labeling them for when I install the harness in the truck. Then I will begin taking the old ESC harness out of the truck and planning where I want to run the harness through the firewall and where to mount the ECM. I think I can get by with using the old hole for the ESC harness if I enlarge it some. Possibly even mount the ECM in the same spot as the old one. If that doesn't take long then I need to look at my speedometer to see if I have a optic on the back so I can run my VSS wire. My fuel pump will be there waiting on me after work. So I can start on that as well.

 

[dabomb6608]

I really want to do this to my Blazer.

Martin

Of all the people to say they want to change from stock on their Blazer...Martin I am disappointed!

But really though, I don't think it is a "terrible" swap. Of course, I should wait till it is running to be able to say that!

 

[dabomb6608]

Moving forward with this swap tonight. Got a decent amount of work done I think.

Started out getting the C207 (under dash) connector wires that I will need to hook up out of the connector and labeled. They are the following. VSS Input, TCC Brake Switch, Gear Selector (Park/Neutral causes ground), Check Engine Light, +12v, - GND, Fuel Pump power wire.

With those awaiting to be hooked up once the harness is installed I moved to doing some actual work on the truck.

I began with removing the ESC harness and computer. Man is that thing simple. Had like 4 connectors tops. Relatively easy to remove. I already had my glove box removed. Just needed to remove one of the HVAC pieces to get to the hole in the firewall. Got it all out and decided that would be the perfect location to feed my harness through. It is just off center of the tunnel towards the passenger side. Should leave me with plenty of main harness to locate the ECM inside the cab. Hope to be able to reuse the old ECM holder with a little modification.

Next up was looking into my Brake Switch, Gear Selector Switch, & VSS options.

Removed the gauge cluster and was happy to see that the speedometer had the optical VSS on the back of it with the buffer in the harness. So I should be able to splice into the signal wire and use that as the VSS signal. Moving on to the brake switch I should be able to use the cruise control brake switch as my place to splice into. It supplies power to the TCC.

I then looked at my gear selector switch, commonly called the neutral safety switch, and it has the style with only the reverse lights connector and the neutral safety connector going to the starter...BUT here is the catch. I only saw one connector on it. What looked like the reverse lights. There was a spot for another connector that had 2 male spades. My guess is it is where the neutral safety connector would go...so that got me thinking...how in the world has my truck started all these years without a neutral safety plugged in??? And where are the wires and connector that should go there?

Either way I plan on replacing it with the updated version that also has a spot for the gear selector switch to plug into. All it does is supply ground in park and neutral. The opposite of what the neutral safety switch does for the starter.

That leaves only a 12v connection, ground connection, and the check engine light to figure out. No problem, 12v and ground are no brainers. For the check engine light I will turn to a cool thing my dad had on his Blazer that he installed TPI on back in the early 2000's. He had a multi color LED mounted just above the HVAC controls on the dash. If the engine was running and didn't have an error code it was green. If it was running and had an error code it was yellow. I seem to remember it turning red if there was a serious problem...or maybe thats if the engine was off...I was a youngster the last time that thing actually ran. Its long gone now.

I also got the new TPI fuel pump installed into the new sending unit. And since this harness is for a small cap distributor and I have a spare large cap distributor I needed to convert it to that. Most people go the other way so there are adapter kits to go large to small. Not so going small to big. So I decided to cut the distributor connection from the original harness I took out of the truck tonight and with two minor modifications it fit into the large cap distributors plug. Gotta love when things work easy like that.

 

[82355]

Of all the people to say they want to change from stock on their Blazer...Martin I am disappointed!

But really though, I don't think it is a "terrible" swap. Of course, I should wait till it is running to be able to say that!

It's a shame they never made the TPI 350 an option in our trucks. It was much more of a truck engine than a car engine.

Martin

 

[dabomb6608]

It's a shame they never made the TPI 350 an option in our trucks. It was much more of a truck engine than a car engine.

Martin

I agree, of all the vehicles to need that extra low end torque the trucks would've been #1 on the list. It even would have raised their CAFE MPG numbers.

 

[dabomb6608]

Putting this here mainly as a reminder to check my idea. But I am going to test the two open spade terminals on the gear select/neutral safety switch on my column to see if it is normally open circuit until in park or neutral. If it is then I might be able to make that work as my park/neutral switch instead of replacing it.

 

[jekquistk5]

Putting this here mainly as a reminder to check my idea. But I am going to test the two open spade terminals on the gear select/neutral safety switch on my column to see if it is normally open circuit until in park or neutral. If it is then I might be able to make that work as my park/neutral switch instead of replacing it.

On tbi its open to closed ground.

 

[dabomb6608]

On tbi its open to closed ground.

I think we are on the same page.

If for whatever reason my truck doesn't have the neutral safety switch plugged in the spot that it should go on that part then that means it should be closed in park/neutral and open in all other gears. From factory it would have the 12v going to the starter from the ignition. Allowing it to only start while in park/neutral. But since nothing is connected then I should be able to connect one side to ground and the other side to the ECM and it supply ground while in park/neutral.

Still completely baffled at the fact that nothing but the reverse lights are plugged in on that, but my truck has started just fine for all these years? Maybe it was bypassed? Can't say I have ever intentionally tried to start my truck while in gear. Maybe it actually can because of a bypass? Looks like I have some investigating to do to find the purple wire going to the starter under the dash.

In other news, tonight I will be getting a intake gasket set to start tearing the motor down to put the TPI lower intake on and the fuel rail/injectors. Hope to get that installed tomorrow. I am going ahead and doing that so I can begin figuring out a fuel line route from the rail down to the hard lines along the frame. Then I will place a fuel filter that's rated for high pressure but has hose barbs in a spot I found about half way up the hard lines from the tank that has rubber hose separating the front hard lines from the rear hard lines. Of course all rubber hose will be Fuel Injection hose. Then the fuel tank to hard lines will need to be planned. I also need to run the 3rd line for a fuel tank vent. I might just run a line up next to the rear axle vent and put a filter on the end of it. I'm not running a Vapor Canister anyways so no real need to run it all the way to the engine compartment except for possible water intrusion. Just need to run it high.

 

[jekquistk5]

Let me rephrase that. For the ECM to know if its in park/neutral it is grounded. For elevated idle during drive it is open. The neutral safety switch is completely different. I'll dig through my FSM see what I can find.

 

[jekquistk5]

Also found this

 

[dabomb6608]

Let me rephrase that. For the ECM to know if its in park/neutral it is grounded. For elevated idle during drive it is open. The neutral safety switch is completely different. I'll dig through my FSM see what I can find.

I'm pretty sure I know what you are saying Jess.

Here's what I am saying that I am pretty sure is the same but I might not be wording everything correctly.

I have on my steering column the equivalent of this minus the single terminal to the right.




What I technically should have for this swap is what is shown in the pictures with the extra terminal. It was found stock on the TBI trucks. Maybe others as well. I know it wasn't found on mine stock.

Because the one I have doesn't have the extra terminal needed for the swap (supplies the ground for ecm when in park or neutral) I needed to swap it out for the correct one with the extra terminal.

Here is where I think the confusion might be in communicating this...

The one on my truck doesn't have anything plugged into the spot where the "Start" wires should be. The purple going to the starter solenoid and the "presumably" purple coming from the ignition.

How, why, when this happened I don't know. I know I didn't do it so who knows.

So, my theory is that those 2 empty terminals form a closed circuit when the shifter is in park or neutral. If I am wrong then I have to get the correct part for my column with the extra terminal as shown in the pictures above. If I am right, then I connect one of the empty terminals to ground and the other terminal to my ECM Park/Neutral Wire. Which is Orange/Black just as shown in the second picture for the terminal on the right.

 

[dabomb6608]

Also found this

Yep, we are indeed saying the same thing. Was typing as you posted that. Picture that picture without anything for the purple wires or the extra ground wire to the relay.

 

[jekquistk5]

Yep, we are indeed saying the same thing. Was typing as you posted that. Picture that picture without anything for the purple wires or the extra ground wire to the relay.

Yes that switch just allows 12v to pass to the solenoid while in the N/P position. Only is active when the key is put to start.

 

[dabomb6608]

Yes that switch just allows 12v to pass to the solenoid while in the N/P position. Only is active when the key is put to start.

Correct, the 12v is only applied through the switch when key is turned to crank. In my version, it would have continuous ground on one side. And supply ground to the other side only when in park/neutral. Just as the ECM needs.