Impending Vortec Swap (1 Viewer)

[lazy]

My date finally showed up to the dance....

 

[DieselDriver]

Nice! Can't wait to see what you come up with in mounting them in the factory gauge cluster.

 

[jkdowty]

I bet you could cut up the factory Gage's and fit them in there behind the clear plastic lense... Making cleaning dust off a breeze... Or a piece of brushed 1/8" aluminum would look slick too...
What's the part number on that set of Gages? I'm probably going to use the factory 80 Gages, and factory 80 senders but by the time I get to that point I might have the money to get those beauties...

 

[lazy]

Here is my first stab at mating the 2 systems. This is obviously to just get the motor running and gauges, which I'll do once this thing is running.

Any suggestions before I fry something?

 

[lazy]

I planned to get some thin ga cold rolled steel (16?) out of the scrap pile at a near by metal place. That way I can weld brackets on and what not. Use some cardboard to make a template and then plasma cutter time.

VHx 1060 is what I got. Unfortunately Dakota digital wouldnt make me an oil and Trans temp gauge. So ordered some custom autometers which I think will fit in the gauge cluster, but I will probably mount somewhere else just to keep the sweet look of the Dakota digitals similar....

 

[jkdowty]

I planned to get some thin ga cold rolled steel (16?) out of the scrap pile at a near by metal place. That way I can weld brackets on and what not. Use some cardboard to make a template and then plasma cutter time.

VHx 1060 is what I got. Unfortunately Dakota digital wouldnt make me an oil and Trans temp gauge. So ordered some custom autometers which I think will fit in the gauge cluster, but I will probably mount somewhere else just to keep the sweet look of the Dakota digitals similar....

A pillar mount? That would look sweet!

 

[bloc]

Here is my first stab at mating the 2 systems. This is obviously to just get the motor running and gauges, which I'll do once this thing is running.

Any suggestions before I fry something?

Just realized I was wrong.. you'll need more than the E7 connector.

One clarification.. the "fuel pump relay" isn't actually to switch the pump on/off.. it's to switch voltage. Toyota uses a system where it's lower voltage by default (routing the circuit through a resistor) then the fuel pump relay bypasses the resistor when the ECU calls for it on the E7 pin 13.

The 'circuit opening relay' acts more like a traditional fuel pump relay.. actually switching fuel pump voltage on or off. it is controlled by the "FC" circuit from the toyota ECU, Connector E4 pin 14 Red/White. And not that it applies to you, but this is only in 95+. 93-94 uses the AFM and a circuit energized with STA+ from the ignition switch.

Either way, you no longer have connector E4 so you'll either need to enable the fuel pump voltage relay by tying IH1 pin 17 Red/White into your fuel pump control circuit, OR bypass the resistor in the relay/resistor wiring. On a 95+ it'll be on the passenger side of the engine bay. It's a small aluminum box with cooling fins on it, under one of your hood struts. Four wires.. (pins 1,2,3,5) If you connect pins 5&3 (Red/green & red/black) it'll bypass the voltage step-down. Obviously this may stress the pump more than stock.. though I'm not sure how that applies to the GM fuel pressure control system.

On your chart you show E7 pin 12 controlling the fuel pump.. keep in mind this doesn't get +12v without being switched on by the EFI Main relay (along with +12v for most of the other engine-harness sensors).. E7 Pin 3 Red MRLY needs to get +12v. The relay itself is located in the underhood fuse block, I'm assuming you kept it. On toyota this is controlled by the ECU.. if GM has equivalent output, if not use the ignition switch I guess.

Another note.. on a 95+ MRLY control goes through the dash harness. For anyone taking notes about a 93-94 swap it is controlled through the engine harness to the same location, so you'll have to find another way to make that circuit complete. Not hard with the GM ecu potentially ending up next to the fuse block.. but an important distinction between the two chassis.

 

[lazy]

Wiring Diagrams for GM engine here.

Still sorting through this fuel relay thing, but I think I can run through relays on the GM side to get it figured out....

I depinned everything and no cutting outside of the common wires that tie things together at junctions, so I can piece it back together if needed.

 

[rockrod]

PM me with your email if you want a copy of the pinout i made up. Ditch the whole two step fuel pump relay thing. The vortec motor needs a constant high pressure supply. Toyota used this to help control fuel pump noise so that the pump speed is slow when fuel demand is light but when you punch it the pump pressure is increased by sending more power to the pump to keep the motor supplied. A turbo supra pump is more than enough pressure and volume for the vortec and is super quiet on full 12v power.

 

[half k cruiser]

Pardon my ignorance, so the factory gauges won't work with the vortec swap ? Those Dakota's look cool, expensive and cool !

 

[DieselDriver]

When you striped the GM harness down to run stand alone, did you add relays for the GM ECM to run the fuel pump and electric fans?

 

[lazy]

Pardon my ignorance, so the factory gauges won't work with the vortec swap ? Those Dakota's look cool, expensive and cool !

Factory gauges work. This is just kind of a splurge. I know they are expensive, but you can't compare the price of the gauges as the difference in running stock. You'll still need a speedo correction, you'll still need something for the tach etc if running stock gauges.

When you striped the GM harness down to run stand alone, did you add relays for the GM ECM to run the fuel pump and electric fans?

I'm planning to run the GM fuel pump relay found in the massive fuse box.

 

[lazy]

k....Just to clarify, I havent removed any relays from anything, just wires which go to relays. and that is for toyota engine harness only, I have not yet touched the body harness.

electric fans are being run by a stand alone system, dcc pwm controller.

Sorry, I'm a bit slow. But, I think I have this figured out. You don't want to use the GM relay because you have to move the wiring to the fuel pump over to the GM relay. But, E4 pin 14 (R-W wire) goes to IH1 pin 17. So, I should be able to connect GM GReen pin 9 to to the IH2 pin 17 (or the output to the circuit opening relay). This is what @bloc said. I'll bypass the step down by connection wires 3 and 5 in the fuel pump relay, as I have the supra pump. I'll probably need to ground E7 pin 12.....

onto the starter....

 

[bloc]

Don't ground E7 pin 12. That is the negative side of the circuit that EFI Main relay switches.. it'd just pop your EFI Main fuse as soon as you gave +12v to E7 Pin 3, which is what the ECU uses to turn on the EFI Main relay.

Otherwise, I think you typed IH2 in the previous post when you meant IH1. Otherwise yes, you could easily use the Circuit Opening Relay (Ih1 pin 17 red/white) to act as your fuel pump relay and insert the resistor bypass you mentioned. Unless the supra pump pulls a whole lot more current than the LC one everything is rated for the correct draw and basically functions that way already.

 

[lazy]

Ok, round 3....IH1 17 (R-W) to ground, E7 12 yellow to GM dkgreen. That should make it just a simple relay, correct? I've taken out the EFI wire, but can figure out how to put it back in if the above won't work.

 

[lazy]

Had a wiring helper today .

 

[bloc]

IH1 17 R/W to ground should work. That will enable the circuit opening relay any time the ignition is on.


First you need to know what the DK green in the GM harness does. Does it switch ground or +12v?

Second, without something giving +12v to the E7 Pin 3 wire to switch the toyota EFI Main relay on, you won't get +12v on E7 pin 12 yellow.

Third, how did you "take out" the EFI wire? The switching wire (red, pin 3) goes from E7 connector, through the dash harness, along the driver's side inner fender, into the underhood fuse block. Unless you were cutting wires out of the dash and body harness that wire should still be there.

That said, the circuit that that relay switches (yellow/red, eventually becomes Yellow only at IH1 connector pin 22, yes it's redundant) DOES go through the engine harness. It jumps from the fuse block to the 4-pin connector under the power steering reservoir (EB1).. so if you ditched the toyota harness, you are correct and don't have that relay-protected circuit going to the area of the stock toyota ECU any more.

One possible solution is to splice ignition +12v (E7 pin 1 Black/blue is a potential candidate) to the red E7 Pin 3 wire. This will trip the EFI Main relay any time the ignition is on. Then that will switch +12v to the yellow-red wire right behind the stock battery location.. which is where it seems a lot of vortec swappers stick their GM ECU.

That said.. this may be adding relays into the system that aren't needed. I'd suggest checking out @rockrods recent thread on GM wiring. It is more specific to 94 LCs and as I noted in there there are some differences.. but it's at least another perspective on how to handle the relay switching. Vortec Swap - Pin Out Sheets

 

[lazy]

First off, thanks to @bloc for helping out so much and showing so much patience with my ignorance....It's been 13 years since I took circuits in college, and I know just enough to be dangerous.

So....after staring at the EWD for a couple hours tonight, here is what I have learned. If one desires to keep the 2 step relay (or whatever it is called), you will need to retain the toyota ECM. Which is what I think @bloc said 2 days ago when I began this mess. Again, it takes me some time for things to set in. I assume the toyota computer grounds E7 pin 13 W-R when it is calling for more fuel (not sure what the logic is built on? rpm? STFT?), sending the full 12V to the fuel pump and bypassing the resistor.

Unfortunately, GM just uses a single relay instead of the 2 step thing above. So, if one desires to keep the keep it, you'll need the toyota computer and the logic it is built on. Which also means you'll need any inputs for whatever builds the logic to ground the "fuel pump relay." At least as I understand it. Not certain on the last part, but you'll need the toyota pcm.

@bloc is correct above (again), as I did remove the Y-R wire, which seems to give 12V to whatever needs it in the engine harness (HO2S, MAF, etc) and does come into IH1 and turns to yellow (and also is E7 pin 12 Y) and then goes to the circuit opening relay as the 12V supply at the switch (not sure on the terminology...). This comes from under hood fuse block, to EB1 (by the distributor, single wire, 3 terminal connector). I've deleted all that stuff.

For me, right now, I plan to do the following:

• Ground pins
  • IH1 17 R-W
  • E7 pin 13 W-R
• Connect GM wire from the "Green" block, pin Pin 9, dk green/white to E7 pin 12 Y

per lt1swap....Pin 9 - Dk Green/White - Fuel Pump Relay Control - This wire the PCM supplies 12v+ to control a relay for fuel pump. PCM will turn on the fuel pump for 2 seconds at initial key on. When the engine cranks or starts, the fuel pump will then continue to run, untill the engine stops, or you shut off the key.

I should then be able to ditch the toyota ECM. I'll also have fewer wires running around. And system built how GM designed theirs. GM seems to keep a constant 12 V and the dk green/white wire switches the relay. What I propose above is using the 12V of the wire to run the fuel pump....above will have a switched relay control, and the GM PCM controls the dk green/white wire voltage as well (0 or 12V).

I think this should work?

 

[bloc]

IH1 17 to GND will let ignition switch control Circuit opening relay. Correct, but, potentially redundant and not the best way to go. ECU loses control of fuel pump relay.
E7 13 to GND will lock the "2-step" fuel pump relay into full-voltage mode. Correct. Personally, I'd rather bypass this relay and eliminate one point of failure, but what you propose ultimately would work.

GM ECM DkGn to E7 pin 12 isn't a good idea. The GM ECM is supplying +12v when it wants to turn on the fuel pump (via relay).. but the yellow wire is ultimately what provides the +12v for the whole fuel pump. Normally this is a big wire, controlled by the EFI Main relay, and can carry more than enough current (along with most of the sensors, like you mentioned). Your configuration would have the GM ECM supplying fuel pump current.. no bueno.

Since the toyota ECU switches the COR on by controlling GND, and the GM ecu switches the fuel pump relay on by controlling +12v, you have a little bit of trickery to do. Simple as installing another relay controlled by GM ECM to switch GND like the toyota ecu does.. but again, more complexity. I'm curious what other people with later model cruisers are doing with vortec swaps.

And for the record the Circuit opening relay is different on 93-94 trucks vs 95+.. so I don't think what rockrod did will work for you. Even then I'm not sure how it worked out.. seems like there's a wire missing that would control the COR and the GM ECM ultimately providing current for the pump.

 

[1973Guppie]

Had a wiring helper today . View attachment 1308106

this is perfect! now I know what to do with all the random stickers I get, stick em to the 2 year old....