Re: Tbi swap build thread
 

Thanks; I was planning on upgrading my 90 crew cab R3500 to a 4L80E and was figuring to use the 7427 PCM...I'll keep looking for the parts.

And thanks, RF, for supplying the pinouts. What kind of tool do you need to move the pins around? I've done my share of Molex; anything similar?

Travis

Re: Tbi swap build thread
 

I did a bit of research into 7427 PCM which is by no means complete. From what I was able to find 7427 PCM was used with different power train combination's. For light and medium duty $0D EPROM mask id was used for 1500 and LD 2500 running the 4L60E transmission (and manual). For heavy duty applications with 454 with 4L80Es $0E or $31 EPROM masks were used in 7427. Interesting enough 6395 and 8625 PCMs were superseded by 7427 in LD applications.

For example in 95 GMC 3500 van 350 TBI with 4L80e 7427 PCM was loaded BNKM EPROM. There is little difference between in engine variables between $0D, $0E, and $31, however 4L60E and 4L80E trany code is different (one of the valves logic is flipped) and there is a harness difference between PCM and trany.

For JY picking - 6395 or the 7427 running the $0D mask were used with 4L60E. The HD trucks and vans (3500) used the same PCM's but ran the 4L80E and either the $0E mask in '94 or the $31 mask in '95. IMHO if you modify the trany wiring harness from 4L60E to match 4L80E (extra sensor and different logic) with appropriate .bin and mask, it should work great. More research....


Port fuel modification (i.e. TPI, etc) involves modifying injector driver circuits. I have not looked into it, but Fast355 runs 305/TPI/4L60E with 7427 in a full size van!! Check out his Youtube videos.

//RF

Re: Tbi swap build thread
 

Hokay, this is gettin' more interesting...I really enjoy modifying stuff, so we'll have some fun...

I haven't put my hands on a 4L60E and a 4L80E to compare; do they use the same connectors? If so, I'm guessing that'll make finding a donor harness much easier. I've got to customize the harness anyway since it's going into a square body. No problem; I've done similarly many times. Patience and tape will get it done.

Sounds like I need to find some 94 95 electrical diagrams.

Which valve's logic is inverted?

Travis

Re: Tbi swap build thread
 

68 TT: the answer is YES, you can burn the EBL optimized program to a PROM that you can use in a stock ECM. Bob's answer suggests that it still may not be optimal, but he burns a PROM and has it in a stock ECM as a back-up for his on EBL, so it should work to at least get you home.

Here's his response:

Mark,

Yes, what you suppose is viable. With a stockish engine a stock ECM with a stock calibration will be able to run the engine. And get the vehicle from point A to point B.

If the engine combination is far from stock then a stock ECM with the major calibration parameters from the EBL will also get the vehicle on it's way. The major calibration areas are the VE table, the SA table, and the injector base pulse constant (BPC).

I do this myself. Although I've never needed it. I carry a stock ECM with a modified calibration in it in the trunk. Figure that push comes to shove I can continue to drive the vehicle with it. Won't get the best performance or mileage, but that doesn't matter.

One item on your side is the construction of the EBL board. The parts are industrial temperature rated, and the board is conformal coated. The same as the OEM GM ECMs. It is built for reliability and longevity.

Regards,

BobR.
Dynamic EFI

Good luck again!

Mark

Re: Tbi swap build thread
 

Travis: see here (yes, it is Dynamic EFI's site, so I'm shameless:lol:).

Re: Tbi swap build thread
 

RF - thanks for confirming what I thought would be a pain in the a** and reinforcing my decision to go the Flash EBL route (not that I really needed much reinforcement:rolleyes:). Good luck with taming your KS to ignore those Delta 40's (must sound good!).

Re: Tbi swap build thread
 

Travis

I have not had the chance to dive into 4L60E and 4L80E differences. One possibility is to get FSM for 94-95 LD and HD and do side by compare. Another is to get ATSG transmission repair manual. Alldata is another potential source for this information.

However, there are, as always good folks that love to tinker, modify, etc
4L60E was used in 4gen
http://www.ls2.com/boggs/a4/automati...schematics.htm

ATRA actually provides a very nice summary connectors are different!
http://www.atraonline.com/manuals/ge.../tetdv-c3e.htm


4L80E
http://www.atraonline.com/manuals/ge.../tetdv-c3i.htm
http://forum.efilive.com/showthread.php?t=4305

note that there are differences between early 91-92 4L80E and later

//RF

Re: Tbi swap build thread
 

This is a good thread

http://www.performancetrucks.net/for...d.php?t=413157

now you see what you did !!!

Re: Tbi swap build thread
 

Outstanding! This is the kind of info I've been looking for. Looks eminently doable. Now I gotta start scrounging some harness pieces to play with.

I recently bought a '91 GMC 3/4 parts truck with a rat & 80E but haven't gone to pick it up yet (250 miles away) so haven't started playing yet. It's supposed to run but knock; have to wait and see what I can tell when I get it here. I bought it thinking I'd knock it in the head for parts to upgrade my crewcab, but I might fix it and drive it and start looking for parts to do the crew...

This is going to be fun.

I'm the new guy here, so I'm just asking...should this be a new thread? It's kinda drifted pretty far from where CJRacing started...I think his original intent was to provide a start-to-finish primer on a stock TBI conversion. I'm really, really enjoying getting into the transmissions and more advanced implementations, but don't want it to get confusing to the guy who just wants to put the TBI from an 88 sub on his 84 pu...there are lots of folks who would benefit from that (me being one of 'em...)

But like I said, I'm just asking...

Travis

Re: Tbi swap build thread
 

There were also 4.3 V-6 applications with the 4L80E which seems kind of odd but they did it. It is what my 4L80E came out of. 16147060 PCM from 1992.

Re: Tbi swap build thread
 

Quick question:

Is it ok to mount the O2 sensor on the header pipe coming off of a cylinder, any cylinder, or should it be mounted at the collector?

The truck has dual exaust.

I mounted the intake and TBI adapter plate this weekend and should have the truck started again next weekend.

Thanks, Pancake.:metal:

Re: Tbi swap build thread
 

You want it to sample as many cylinders as you can so it gets a good average so putting it in the collector is best. Make sure you are using a heated sensor with headers. They lose too much heat to work well with a standard O2 sensor.

Re: Tbi swap build thread
 

Awesome thread.Couple of questions.I have a Summit harness that has a fused fuel pump wire already.Do I need to tie this into the Comp?Also is B1 a switched 12V or constant?I would like to dumb the system down.What is the minimum needed to run the TBI.I am sure I will have more once I get to doing the wiring.
I guess I should tell you about the project.It is a CJ/Buggy thing.All the drivetrain is from a '88 1ton crewcab truck.FI454/SM465/205.I have the stock engine harness.And the Summit Racing universal wiring harness.I want the advantages of FI on the trail but want to keep it simple at the same time.Thanks Brady.

Re: Tbi swap build thread
 

I'm not familiar with the Summit harness, but assume it replicates the factory harness...B1 is hot all the time. Factory did it through fuseable link instead of a fuse for increased reliability.

Don't know about the Summit harness's fuel pump provision; is there a fuel pump relay? You want the ECM to control the fuel pump so that it only runs if the engine is running or cranking.

The factory bypassed the fuel pump relay with an oil pressure switch on some applications so that the fuel pump would run whenever there is oil pressure.

Why do you not use the factory harness? Incidentally, I'd be a buyer for that factory harness if you don't use it...the harness in my 90 454 crew cab has been burned and is a constant source of grief...haven't had much luck finding a big block harness in any of the yards around here...

For a basic system, you'll need unswitched 12V, switched 12V, and ground. You'll also need a cranking wire (connected to the starter solenoid) Don't believe you need the park/neutral signal since yours is a manual transmission. You'll also want to provide a "check engine" light. That should just about do it, assuming the harness connects all of your sensors etc. Does the Summit harness include the ALDL connector? You're going to want that for sure.

Travis

Re: Tbi swap build thread
 

I did a little research on the Summit site and found this link for a pdf of installation instructions for the Painless harness for TPI; TBI is very similar and should answer your questions:

http://static.summitracing.com/globa...0102_60103.pdf


Travis

Re: Tbi swap build thread
 

I will use as much of the stock engine harness as needed.I got the Summit harness for the rest.IE.tail lights,headlights,gauges.It is a basic kit.Not really for TBI.

Re: Tbi swap build thread
 

Great thread guys! Maybe too great b/c I have accumulated all the parts and pieces need for a tbi swap of my own. I have done my homework and I think I have a decent grasp of what I need and what to do with it. But I do have a couple of questions and I know you guys have the answers. I think my harness came out of a 1990 van don't know if it was a 5.0 or 5.7 or what ecm #. The ecm I have is a 1227747 AMUR from a 1988 c15 w/5.7. My harness matches the pin out cjracing15's in post #8, except for two wires are swithced. D2 is purple and goes to the MAP sensor and A11 is black and goes to the coolant temp sensor. My harness matches rfmaster's diagram in post #108. Should I swap the wires? My other question is VSS related. Would a universal cruise control speed sensor work? Sorry for the length and thanks for the thread it rocks!

Re: Tbi swap build thread
 

No problem on the length. Your ECM with AMUR BBC calibration was used in 1988 C/K 1500 with a 350 TBI/700r4 combo. Generally speaking wire colors used in GM EFI harness remained more or less the same. What's really important what those wires connect, ie sensor <-> ECM.

ECM D2 is a sensor ground - I have seen various colors used for this circuit, but truck based harnesses tend to use black with red stripe.

ECM A11 is another sensor ground and can be either black or purple. This sensor ground does not connect to the temperature sensor itself, but it uses a thermostat stud for a ground connection.

//RF

Re: Tbi swap build thread
 

I'm putting a 1950 truck on a s-10 frame with 89 5.7 an 700r combo -- my question is -- my transmission has 3 wires coming out of it --tan/blk, purple, and blue -- what do these hook to? Also, I have a factory big 5 wire relay for fuel pump -- would it be ok to run all my pink wires through it (i.e. injectors and computer)?

Re: Tbi swap build thread
 

Thanks rf, good info. I found an explanation for the slightly different pin outs. Inside a C3 ECM D1 and D2 are solder connected and A11 and A12 are solder connected, so when the ground wires attached to the block all these pins are connected. I found a pic at

http://www.justih.org/Binder-Bench/s...7668#post27668

I also thought of a couple more questions. All of my senors came w/ my harness and I am not sure if it was a 5.0 or a 5.7. How can I tell if they will work the 5.7 ecm 1227747 AMUR? I am going to order some 3/8" aluminum tubing from summit for my return line. What is the best way to connect it to the rubber line and keep it from slipping?

250cows I am no expert so you might want to get verification from some of these other guys, but on my schematic: tan/blk-A7(TCC or shift light), purple-brake/stop light switch, and blue-c7(High Gear) Good luck with your project. It sounds cool!

Re: Tbi swap build thread
 

ECM D1 is a ground (blk-wht) ckt-450
ECM D2 is a sensor return ( blk) ckt-452 which is the same as ground.
ECM A11 is a sensor return (purpl) ckt-445
ECM A12 is a ground (blk-wht)
Binder board is another good resource for TBI conversions. I'll have to pop cover on one of my ECMs to take a look.

Most of the sensors used for TBI engines are the same except for knock sensor which might be different depending on the engine displacement and cam shaft type. There are variations on TPS style, and IAC is different between BBC and SBC. All sensors have GM or Delco part (basic) numbers:

Manifold Absolute Pressure (MAP) 16137039 (should have green or black connector insert)
Throttle Position Sensor (TPS) 12116257 (depends on the TB shaft style!)
Coolant Temperature Sensor (CTS) 25036979
Engine Spark Control Module (ESC) 16128261
Idle Air Control Valve (IAC) TB dependent - see above
Engine Spark Control Module (ESC) 16128261 (use earlier CCC version with non roller engines or if you have a very loud exhaust system)
etc

To keep rubber hose from slipping from 3/8" tubing I use beading tool from SkyGeek. Alternatively, Earls sells ID specific beading tool. Use search I think I posted part number earlier in this thread.

700R4 typically has three wires:
LT-Blue - 4th gear indication switch (pulls to ground when in 4th gear)
PPL - Brake switch (NC) to TCC solenoid
Tan-blk - ECM A7 TCC solenoid enable (typically pulls to ground to enable TCC)

//RF

Re: Tbi swap build thread
 

I am running a set of old rusty long tube headers. I have a set of shorty block huggers. Does anyone know if they will fit on my 69' k5? I dont want to have any trouble with the stock O2 sensor not reading right. If the block huggers wont fit does anyone know of any other small block manifolds that will fit? My original ones were cracked badly and hauled off for scrap years ago.

Re: Tbi swap build thread
 

Most wrecking yards that work with trucks carry new replacement exhaust manifolds. Not too expensive but a new pair of headers is less expensive.

I had one crack on my 90 Z71 and decided to buy the Summit truck headers instead of putting on another manifold. The Summit brand headers ended up being Flo-Tech headers with the logo emblem still in place. I think they were right about $80 and fit great.

Re: Tbi swap build thread
 

The are couple of issues that tend to pop-up when people switch from cast iron exhaust manifolds to headers in closed loop control car/trucks. The number one is being the fact that a single wire O2 sensor will run cooler if placed near outlet of the conventional long tube header. O2 sensor must be heated to about 600F for normal operation. Anything less and output voltage drops. A simple fix is to run 3 or 4 wire heated O2 sensor. Another problem that plagues headers are loosening header bolts and or a leaky exhaust flange gasket - causing exhaust leaks that O2 sensor is more than happy to pick-up! In both cases O2 feeds erroneous O2 levels back to ECM effecting commanded fuel delivery to intake.

Please do not get me wrong - I love the performance that headers offer over cast iron exhaust manifolds, but I had to replace 4 pairs of exhaust gaskets, flat surfaced header flanges (cheap dynomax headers), and went through couple set of exhaust bolts and thread locking compounds to keep things tight and in place.

//RF

Re: Tbi swap build thread
 

The swap also leaned out my air / fuel ratio and I had to richen it up some to make it happy again. It was actually down on power after the swap until I added the fuel it needed.