Originally Posted by rfmaster (Post 5971504)

@BigrobDog

OK - thanks for posting photographs - these help quiet a bit.

In Photo # 1
Your 1990 burban donor came equipped with CS-130 Alternator. This alternator has internal regulator. OE external '72 regulator that you have in Photo #2 will not be used. To adapt CS 130 to the '72 wiring is actually straight forward, but it will require a bit of DIY soldering. Are you up for it????

CS130 alternator is rated for 105AMPS maximum output and will deliver around 30 to 35Amps at idle. Which is plenty.

Look at the back of alternator. There, you should see BAT terminal and big fat red wire should be running between alternator BAT terminal and terminal block that is part of EFI harness - mounted on the passenger side firewall. I thinks there is one, but it is taped-up and not clearly visible. That wire should have been a part of '90 burban harness. From the firewall mounted terminal block there also should be a big red wire running to starter main terminal - its also should be a very thick red wire - 8AWG. Please take a close look and capture a photo of it in case if it is not connected. A fuel pump relay should be in close proximity to that firewall mounted terminal block.

Back to CS-130 alternator. There is a multi pin plug with several wires protruding from it.. Most often it is just a brown 16 AWG wire tied to 'L' terminal. This is a alternator light bulb wire. You can NOT connect this wire directly to the instrument alternator light. This connection can only be made if there is a series 150 to 300 OHM 1Watt resistor ( between alternator plug and instrument cluster alternator light). This is done by disconnecting external regulator plug from OE external regulator module and connecting brown wire from CS-130 'L' circuit with a series resistor to terminal 4 of the OE regulator plug - also brown wire. At least GM was consistent with their wire color schemes over decades! . Schematic below does not show this resistor, but it must be there.

http://63nova.nextmill.net/cs-130/CSAltConversion.jpg

Sometime, there is a larger gauge red wire tied to S terminal - this is a voltage sense line. This wire should be tied to a BAT terminal block on the firewall.

Photo #3
This is a tough one - this portion of the harness was connected to 90 burban main feed through block. The wires protruding maybe useless - anti lock computer, windshield wiper motor, temperature sensor, etc. It is best to remove split loom and peel off electrical tape and determine where these wires went.

VSS - this is a long discussion in itself. Do you have 700R4 from donor or you still have THM-350/400???

P/N switch - some DIY is involved but can be easily implemented. Search this thread for schematic.

//RF

Originally Posted by BigrobDog (Post 5973269)

your showing a 4 prong plug i only have 2 prong plug brown / and orange.. so brown to 4 plug and and orange to back of + alternator. is this right , nothing at all will be hook to external 72 regulator.is power wire to dash were the light goes , or is that voltage out put.

Originally Posted by jasons (Post 5980360)

I wired B8 for the AC signal into the dark green lead to the compressor. Now with the compressor pluged in there is continuity between B8 and B1 which is a 12v battery wire hooked to a junction block and also between B8 and B3 the black/red wire to the distributor plug. Is this normal?
It makes me think the AC would always be engaged.
The compressor that is on the engine now is locked up and will be replaced, could this be the cause?

Originally Posted by rfmaster (Post 3580360)

I hate to say but this is not entirely correct. 87 to 89 Full-size trucks used a programmable DRAC module that is incorporated into the instrument panel. Starting '89 all Chevy trucks with rear wheel anti-lock brakes used electronic speedometers. Vehicle speed is monitored by a sensor (AC VSS) mounted on the output shaft of the transmission, where a speedometer cable would normally be installed (exception being 4x4). The signal generated by that sensor (40 pulses per driveshaft revolution) goes to the DRAC (blue and yellow wires) which further divides and conditions the signal for the electronic speedometer, ECM, cruise control and anti-lock brakes. Because of numerous gear ratios and tires there are different DRAC modules. Back in those days switching to taller tires caused a lot of grief as anti lock computer would flake out (same went for cruise control).

In 4x4 applications the VSS is mounted in a transfer case. This VSS (supplies 40 pulse AC signal per shaft revolution) can not be used without DRAC module since DRAC ultimately supplies 2000 ppm signal to ECM.

There are several issues that should be considered before installing donor drive line into '65.

First 700R4 have been known to have weak 3-4 band as well as many other weaknesses identified elsewhere on this board. All of them can be easily corrected by a competent trany shop while you have drive line out. It does not cost too much as long as hard parts are not damaged. The choice is yours.

Second. To get a functioning speedometer in your 65 you'll have to perform a minor retrofit. 700R4 that you have was configured for 4x4 duty with special output shaft adapter to transfer case (NP208???) which does not provide for conventional mechanical speedometer mounting flange! The only other place to get mechanical speedometer drive is from transfer case and that will depend on a transfer case. You'll have to figure out which transfer case you have - search 4x4 forums for speedometer retrofit thereafter. In the end you may find that having mechanical speedometer in your 65 may not be possible.

Third. To get ECM working right you'll have to extract DRAC module from your instrument cluster - this module typically has a three letter coded label attached to it. You'll have to research cluster wiring for '89 to determine which wires from DRAC were used to power it up and to supply ECM with 2000ppm signal.

Fourth. From photo's it appears that you have lots cut wires in your harness. Make a list of color and wire gauge of these cut wires. This way we can figure out what was cut and how to fix it.

Fifth. Clean up - it is a lot easier to work on engine that does not have oil leaks! Sorry, to point out obvious stuff.

Post your questions and findings - this very interesting since this is a very first 4x4 TBI retrofit!

//RF

Originally Posted by rfmaster (Post 4441706)

Well - not that simple. While it is true ECM needs IGN and BAT (+12volt), you also need to connect IGN +12 for injectors, P/N switch, brake switch, TC control for 350C or 700R4 trany and VSS to make the best out of ECM.

//RF

Originally Posted by BigrobDog (Post 5973199)

i think it is on the back of the transfer case on the out put of yoke.but i dont think u can add a mechanical cable .

Originally Posted by BigrobDog (Post 5982475)

what wire are my brake switch on the tbi to ecm so i can tie in to thoes , or is the a post are page on that all ready

Originally Posted by jasons (Post 5990027)

I just tried it for the first time. It fired right up:metal:, but idles at 1,800 RPM:waah:

The timing is set at 0* the tan/black wire unplugged, but I was checking this at the fast rpm's.

I cleaned up the throttle body and put a rebuild kit in it while averything was apart. Other than not getting something right when putting it together I'm at a loss for what would cause this.

Any ideas where to look?

Originally Posted by rfmaster (Post 5990162)

You must perform IAC reset. Search thread - procedure has been posted. Also make sure that IAC has been screwed into TB firmly with a paper gasket. Also check position of your throttle blades - they should be almost touching walls. Minimum idle screw should keep the blades from coming in contact with the walls. Do not touch it at his time until you go through IAC reset couple of times.

Setting base timing at 1800 RPM is ok for starters, but it is better to do this while engine is idling around 650 RPM.

As always check for gross vacuum leaks around intake - PCV, CCP, brake booster line, etc.

Originally Posted by rfmaster (Post 5991556)

OK - yes, you'll need to get IAC replaced.

When you go through the IAC reset the plunger should extend fully and close off air bypass passage. You should hear a clicking noise while ALDL pins A & B are tied together and IAC is plugged into the harness. SES light should be on as well. Your assumption about how IAC operates are correct.

Lets address IAC operation first before moving any further. I assume that EGR valve is installed, but vacuum hose is disconnected???

The other items to be aware of - make sure that all harness ground connections are tied to their respective grounds. There are two main ones - in front by the thermostat housing and one in the back of the passenger cylinder head. Loose grounds will drive ECM nuts!!!

//RF

Originally Posted by jasons (Post 5991590)

The IAC did click when A&B pins were jumpered, I'm just not sure the plunger extended completely, the new IAC valve will be here in a couple hours.

The EGR valve is installed and the vacuum hose is connected. Should it be disconnected for this?

I will double check grounds at the ecm plug.

Originally Posted by rfmaster (Post 5942252)

Ok Guys.


Zooming into high temperature coolant area.
http://i226.photobucket.com/albums/d...psf74f3188.png

Cross over occurs right around 76 to 80C region.

AC Delco G1852 (found on Internet) data stops at 100C (212F) - I do not have this sensor at this time, but would like to re-run it to see how it behaves between 100 and 135C.

Next step is to validate SW5051 with the actual gauge.

Suggestions???? Questions???

//RF

Originally Posted by jasons (Post 6003521)

Do you have the data for the SW5051 sensor broke down as to Ohms at a specific temperature? I have the data for the G1852 from the web, which is probably the same you found, but can't find it for the SW5051. I used the 5051 sender in my Blazer and the gauge pegs before the electric fan comes on at 185*. I think adding a resistor in line would work, but need to know what the difference between the two senders is to figure out how much resistance to add.

Originally Posted by Jonboy (Post 6004741)

Just a quick fuel question, for a swap into an older vehicle. I am getting ready to help a friend do a TBI swap into a '74 Blazer, but it does not have a return line. What is the best way to do one? Should I use rubber line going back to the tank, (and does the return need to be FI rated?), or does it need to be hard line. I am planning on using an inline fuel pump and using the original feed line. Also, where are you guys putting the fuel filter when doing an inline pump?

Originally Posted by Jonboy (Post 6004946)

Wow. I would have thought that the feed line would have been 3/8 already. Guess that's what I get for trying to engineer a TBI swap from 250 miles away. Thanks for the heads up.

Originally Posted by jasons (Post 6004707)

Thanks RF. I was thinking around 30 Ohm would be needed. I'll get a resistor to add and post the results.

Originally Posted by jasons (Post 6005829)

I added a 22 Ohm resistor. The guage is now about 2/3 of the way up the normal range.

Originally Posted by k1blazer (Post 6013488)

I apologize for coming in late in the thread. I have a 72 K5. What did you guys do to tackle the return fuel line to the tank?
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Originally Posted by k1blazer (Post 6028769)

Guys! This is a very long thread and I've read through it. Thanks for all of the information! I have a question though. I probably just overlooked this in the thread but which intake manifold would I use on a '72 small block. The two center holes are at different angles on the later manifold.
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