72 k5 tbi swap

[ta2ed]

im currently in the process of installing a tbi off of a 93 c1500 on my 72 k5, have been reading on here and a few other sites and the wealth of knowledge on here is amazing. But I do still have a few questions. I'm using 7427 ECM. With harness from donor truck.
1 am I able to do without the Drac & wire Vss straight to ecm?
2 I am using cable drive speedo, what Vss from jtr would work for my application?
3 just outside of firewall there is a grey box with what looks like a circuit board inside of it, what the hell does that go to? I can find it in any schematics.
i would post a pic but not quite sure how to do it from phone.
thanks
Frank

[dave w]

1 am I able to do without the Drac & wire Vss straight to ecm?
YES.


2 I am using cable drive speedo, what Vss from jtr would work for my application?
2000 Pulses Per Mile



3 just outside of firewall there is a grey box with what looks like a circuit board inside of it, what the hell does that go to?
I can't help with this one.

dave w

[ta2ed]

Thanks Dave, I know a pic is worth a thousand words, but damn if I can figure out how to get 1 on here lol. I'm gonna try to copy & paste 1 to see if it will work. http://www.gearhead-efi.com/Fuel-Injection/webkit-fake-url://3d61de1c-6610-4d69-a507-26fc088399e9/imagejpeg

[ta2ed]

Well don't reckon that worked lol http://www.gearhead-efi.com/Fuel-Injection/newreply.php?do=postreply&t=3890

[1BadAction]

Looks like something aftermarket, which is probably why you don't see it in schematics. Do you know what circuit it is in?

[ta2ed]

Not right off, but it was in the factory wire harness. This pic was taken after all the wire loom had been stripped off and I had taped what was left with masking tape to try and keep everything together

[dave w]

Well don't reckon that worked lol http://www.gearhead-efi.com/Fuel-Injection/newreply.php?do=postreply&t=3890

It's a factory part. I've seen that part before, maybe a speed buffer, just can't remember at the moment.

dave w

[Fast355]

It's a factory part. I've seen that part before, maybe a speed buffer, just can't remember at the moment.

dave w

Looks like a Hot Fuel module to me. If it is JUNK the thing. They have a tendency to burn up and could catch fire if you don't catch it in time.

[jim_in_dorris]

Hmmm, It looks somewhat like the intermittent wiper motor control circuit I just installed in my wipers.

[bonnieclyde100]

Well don't reckon that worked lol http://www.gearhead-efi.com/Fuel-Injection/newreply.php?do=postreply&t=3890

that has to do with the brake switch and it sends differant voltages to differant areas like to cruise the ecm and abs computer. i just got rid of it because i didnt need it.

[ta2ed]

that has to do with the brake switch and it sends differant voltages to differant areas like to cruise the ecm and abs computer. i just got rid of it because i didnt need it.

bonnieclyde, You hit it on the head,it is purple wire going to e13,its gettin gone TODAY!
Thank you all.

[ta2ed]

Dave,
Is this the vss i need?

Speed Sensor, # 2PRS (http://www.gearhead-efi.com/Fuel-Injection/Pages/SpeedSensors_Speedometer.html)
The two-pulse square wave unit for all passenger car TBI installations, all computer controlled carbureted engines, and 1985–1989 TPI engines. 7/8–18 thread, .104" square drive.

[dave w]

Dave,
Is this the vss i need?

Speed Sensor, # 2PRS (http://www.gearhead-efi.com/Fuel-Injection/Pages/SpeedSensors_Speedometer.html)
The two-pulse square wave unit for all passenger car TBI installations, all computer controlled carbureted engines, and 1985–1989 TPI engines. 7/8–18 thread, .104" square drive.

That is the one.:thumbsup: http://www.jagsthatrun.com/SpeedSensors_Order.html

dave w

[ta2ed]

Thanks Dave! I have 1 other question.....imagine that! I will be running electric cooling fans, am I able to use the ECM to turn them on and off or do I need to use a seperate temp switch and relay?

[dave w]

Thanks Dave! I have 1 other question.....imagine that! I will be running electric cooling fans, am I able to use the ECM to turn them on and off or do I need to use a seperate temp switch and relay?

The quick answer is yes, once the .bin has been modified with code changes, the '7427 will operate fans. The stock chip will not have the fan code. There is also some wiring that has to be added to the computer connectors.

dave w

[ta2ed]

Thanks Dave. Oh & by the way I recived my chip yesterday 1 day AHEAD of schedule. I appreciate the prompt attention. I look forward to doing more business with you in the future & will point anyone I can with the same type of needs in your direction. Thanks again.

[dave w]

Thanks Dave. Oh & by the way I recived my chip yesterday 1 day AHEAD of schedule. I appreciate the prompt attention. I look forward to doing more business with you in the future & will point anyone I can with the same type of needs in your direction. Thanks again.

Thank you for the business, it's very much appreciated!

Now that you are using the Moates.net G1 adapter, and 27SF512 Flash Chip (with ZIF Socket), you are only $85 away from being able to burn your own chips with a Moates.net Burn 2. https://www.moates.net/burn2-chip-programmer-p-197.html?cPath=64

dave w

[ta2ed]

Ok, I have ecm mounted under the dash and all of my wires ran with the exception of the aldl connector. I need to know what wires go where on the actual connector from the ECM. Diagram anyone??

[dave w]

There are only three wires needed on the '7747 ALDL connector, Pins - A, B, and E.

Pin A - Chassis Ground
Pin B - Goes to ECM Pin A9 - Diagnostic Enable
Pin E - Goes to ECM Pin A8 - Serial Data

dave w

[ta2ed]

Is the aldl for 7427 ecm wired the same way?

[dave w]

Is the aldl for 7427 ecm wired the same way?

The '7427 is different.

Pin A - Pin A1 / Chassis Ground
Pin B - Pin A14 - Diagnostic Test
Pin M - Pin F9 - Serial Data

dave w

[ta2ed]

Ok, I got everything wired n fired, cel is on & it's running rough. I plugged the solus pro in and it's not communicating. Any ideas?

[brian617]

Ok, I got everything wired n fired, cel is on & it's running rough. I plugged the solus pro in and it's not communicating. Any ideas?

With the 7427 PCM make sure you are entering in a 94-95 c/k automatic truck in the Solus Pro.

[ta2ed]

Ok, I was using 94 but manual trans, could that be it?

[brian617]

Yep, has to be automatic transmission (PCM), manual trucks use older ECM.

[ta2ed]

SWEET!!! thanks Brian. I'll try it again tomorrow or next day

[ta2ed]

Ok, 1st I want to thank you Brian. 94 w/auto worked!! I scanned the ol girl and got a dtc 54. Seems to run ok (@ idle) but I cleared the codes and it came right back. According to the solus it's a fuel pump relay issue, but like I said it starts right up and idles fine, even takes acceleration

[brian617]

Glad I could help. I don't see that DTC listed here http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-0D post #5. Can you give me the actual code description the Solus lists? I have access to ShopKey, but it would be Monday before I could look it up.

[ta2ed]

You helped a bunch, I appreciate the hell outta it! I figured out my dtc I didn't hook the fuel pump signal wire in on my relay. B2 is signal wire, monitors voltage to the pump. I will hook it up after work today and all should (theoritically) be good lol