TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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Ok well I read through the whole thing and myquestion is as follows.
I have an 88 GM Z71.
The plan is a Single turbo 383 TPI setup running 10 lbs.
How do i re pin my 747 to the 749 ? I read the chart on the first page but they are both for the 746.
And am I correct in understanding that you CAN use the 730 instead of the 749 and just use the 749 code with the 730 ?
Any help would be great.
found this might help
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Splice the right bank injector wires to 4 injector plugs. All the grounds go together to one wire, all the positives go together to the other wire. Now, splice the left bank in place to the left 4 injector plugs. If using TPI plugs, the green plugs go on right side, the red plugs go on left side.
Remove the ESC module. Cut the connector off, and splice wires C and E together. Tape up, and hide someplace neat.
Connect MAT, TPS, CTS, and IAC. Extend wires if needed.
Step 10: Repin
Now, repin ECM connector using following table:
Alright I got all of this done (quicker than I thought) and the only thing I have a question about is the last 3 items 1) Correct me if I'm wrong I just cut the grn/wht wire at the fan relay and and run it to GE8 2) I'm not very good at wiring and I don't understand the last 2 items, if someone could treat me like a 2yr old and tell me what to do that would be great Anesthes you are the man you have saved me and I think alot of people time and money, THANK YOU!!
From memory and reading the table, BD6 and BD7 is the grounds the ECM uses to fire the two injectors, so you need to tie them into the body some where. D1 is already grounded, so you could splice it there. (although in theory you could run the risk of running too much amperage for the gauge of wire). Just splice them to a black wire, and screw it into the body/frame under the dash.
Ohhhh, Ok so I just need to put a pin into BD6 and one into BD7 and ground them somewhere. And if I do nothing to GE8 will it work like it did on my TBI setup, or do I have to run a wire from the relay to GE8 and change something on my PROM, because I don't have the stuff to do PROM work right now. Thanks
Ohhhh, Ok so I just need to put a pin into BD6 and one into BD7 and ground them somewhere. And if I do nothing to GE8 will it work like it did on my TBI setup, or do I have to run a wire from the relay to GE8 and change something on my PROM, because I don't have the stuff to do PROM work right now. Thanks
E8 runs the fan. Just run that to the green wire on the fan relay.. the fan is controlled by the ECM on the '730, not the switch in the cylinder head.
D6, and D7 need to go to a ground or your injectors will not work, and you will get a 'no start' condition.
ok....so I hate to sound like complete retard but I have an 87 Z with a 305 tpi thats MAF setup right now....and MAFs are expensive and mine is bad of course, so I was contemplating going to a later model 91 or 92 SD swap, I have a spare 91 tbi car complete with harness and '730 ECM....is the stock harness on the 91 the '746 everyone keeps referring to? Would I just refer to the above instructions and charts? Also my car has a cable type speedo, would I still need to follow the instructions about the VSS buffer box? I realize the major difference is a magnetic pickup coil going through an analog to digital converter as opposed to an optical hall effect that just outputs a digital signal. I'm a student out at wyotech and I've been through EMS so I am familiar with what all the sensors do and how they work, just not familiar with the GM numbers on ECMs and harnesses...sorry if this is a repeat question.
The L03 in my '91 RS just blew up a few weeks ago, I've been building a 355 TPI motor to replace it
engine is done, and I just repinned the TBI harness for my NVSRAM'ed '7730 this morning thanks to the information in this thread. The swap went perfect, the only wires I had left over were the crank signal and the 2 extra injector wires
should be pulling the L03 and dropping in the new motor this weekend
Yes, They need to be changed, As far as I know you can't make the old TBI ones work. There are 2 different Throttle cables depending on the year your TPI unit came off ( unless your using a aftermarket Throttle Body, they usually come with brackets for both styles ) The TV cable is the same for all years, I believe. I just bought a throttle cable from TPI Parts and it was pretty cheap, and a factory original, They also have the TV cables. Good Luck
My main question right now, is it looks like my throttle and TV cables are too short
I heard no mention of this in this thread, do they need to be changed or is there a way to make them work?
Throttle cable looks easy to change, TV cable is going to be a PITA
Sorry. I was more getting into the specifics of the wiring when I first wrote this post years ago. You, along with whatever new induction you get (hsr, tpi, singleplane, etc) you would need the correct throttle cable and TV cable if you have an automatic.
When I did my swap, I used a singleplane manifold which puts the throttle body in the same location as a TBI car, so the stock cable would be fine.
Good to see this thread is still getting hits years later.
Yeah I just ordered the cables from tpiparts.net, thanks for the link dwolfe88
Got the new engine started today, sounds good, but needs a lot of tuning. The wiring diagrams were spot on though
Still runs super rough, very rich, won't idle. I have my regulator set at 48psi with 24lb LT1 injectors. I was still trying to set the fuel pressure so I haven't connected the vacuum line to the regulator yet, I'll connect that and see how much it lowers my pressure at idle, I'll lower it more on the regulator if I have to then start tuning the PROM
Good to see this thread is still getting hits years later.
-- Joe
This is an awesome thread. In fact, I'm planning this swap on my 1988 C1500. I'll let you know how it goes. I have to give you a big for putting this together.
This is probably the best thread I've ever found on TGO. Thanks Joe for creating this and answering questions about it for the past however many years! And Ruiner, No problem glad I could be of some sort of assistance.
Maybe I'm going about it backwards, but I have a TPI motor, moved a few pins on the harness and am running a 7747. It's still not on the road yet, but should be in a month or so. I also had to add a MAP. http://www.youtube.com/watch?v=-fNfa0DvL8I
i have questions cuz i did a swap on my 88 camaro it was the 305 TBI and put in the 350 5.7 TPI took everything out of an iroc from ecm, wireharness, fuel pump etc and now cant get it to start?? can any1 help it cranks over but dont start
for putting this together. 
