350 tbi harness rework

[Shawn1989]

N00b.
Introduction: my name is shawn prince..... I am putting a chevy 350 inside of a mazda miata to drift with. I know its not a 4x4 but still, 330-400 horsepower in a 2300lb car, yeah, will e tons of fun.
At first the engine was carb'd.... I have never dealt with carbs or distributors before so everything went haywire.... Cause the engine on fire, almost caught the house on fire, and burnt the shit outta my arm.


Chevy 350 miata drift car fire - YouTube


Yeah, thats me. So i said the hell with this, grabbed something im a little more familiar with.... Fuel injection!!! Got it for a steal. 125 for tbi setup off of a 1993 gmc sierra 2wd.... came with everything; harness, sensors, dizzy, computer, you name it.
Now i installed everything and am ready to rework the harness. I have been doing TONS of research and came across pinouts of everything.
My question is:
tearing into this wiring.... i am lost..... to an extent....


the tbi engine needs this to run if i am not mistaken:
pcm
dizzy
coil
oil pressure sensor
coolant temp sensor
knock sensor
throttle position sensor
idle air control valve
02 sensor
map sensor


and i want to keep the mil/cel light and the data link connector so i can reflash it.


thats just to run...... im ditchin the egr, vss, maybe knock sensor, but safer to keep.


now...... can someone please verify if i am correct to removing these pins and wires from the pcm and the engine still functioning like it should?














now, here is what i believe it is ok to remove:
b5, b10, b12
e1, e2, e4, e5, e8, e9, e10, e12, e13
f1, f6, f7, f10, f12, f13


I am running a t5 manual transmission, that is why i wanna ditch most of the crap, save some weight and it will be cleaner.


Will this confuse the pcm to the point where it will not run or run really shitty?


im running the fuel pump on a different circuit.... do you think it will have an effect on the pcm or is it all regulated through the throttle body and injectors?

[conwaymuddy]

I may be wrong as im just starting my first swap, but i think the lack of a VSS may mess with the idle. Just curious but aside from the cost why not go with an ls series motor? Lighter for such a small car.

[Shawn1989]

Out of budget lol

[EagleMark]

I'm guessing this is a 16168625 PCM $E6 mask?

Your going to want the VSS and knock is to easy to wire and a good safety. No need for the oil pressure switch. No need for separate fuel pump circuit as the PCM handles this with a relay, could run a toggle switch to disable this circuit if need be for drifting regulations?

Can't flash this PCM through ALDL port, still need the port for data! This PCM has a memcal with chip that needs to be flashed/burned.

Glad you and your home survived the fire! That video was viral here awhile back and a good example of how gas fires can quickly get out of control, you panic and do all the wrong things! Thanks for owning up and sharing! We've all had some bad things happen but rarly get it on video.

You know an EFI fuel pump, system would have been a bigger fire right? Got your fire extighusier yet?

[Shawn1989]

16196395 is the pcm number with BJLH as code.

care to explain about vss? Dont plan on street driving very much....
all i plan on running is a 4-in-1 gauge (rpm, volts, oil press, temp)

Nothing about a fuel cut but i wanted to run it through a seperate circuit/toggle for my own safety and of course anti-theft.

Oh yeah, nothing matches the pinout on this aldl, its setup weird.
the chip is a delco 8070 BJLH
the numbers i see on it are 4895, 3301 and to the right of that is 1263289

lol ye, i have tought skin so people can say im a dumbass so on so fourth, but frankly, its just the intenet lol and i have 2 in the garage and 1 in the kitchen :)

will then engine run correctly if i remove all the wires and useless junk that i listed above?

[EagleMark]

Fuel pump relay is a separate circuit. The PCM just turns on the relay and there is also a fuel pump On signal back to B12 IIRC. Can just put a toggle in the F6 wire.

This PCM uses VSS obviously for the E trans, which you don't have so that is fine. But in programming it has 2 fuel and 2 spark tables. One for idle and one for off idle, VSS is used to tell the difference. I have tuned one once without VSS just to prove it can be done! Way to hard and would never do it again for the cost and effectiveness of a VSS which also improves idle quality when returning to idle.

IIRC there are only 2 wires needed in ALDL port, a ground pinA and data pin M

[Shawn1989]

So i can take my fuel pump power wire, tie it into the relay, ground it amd toss in toggle then everything is holden with it?

And since my t5 speed sensor is electronic (1996 camaro v6) (2pin) in theory it should work correct?

If there is only 2 wires, how do you jump it with 'b' being the test signal? And what wire goes to what pin on the pcm?

[Shawn1989]

also stupid question....... is the knock sensor the same thing as the electronic spark control unit? [esc]? research says yes and more research says no.

hmmmm, a different vss pigtail has already been spliced in and it plugs right into my sensor. score lol but i traced the wires back and they lead to a bigger 23 pin connector which i have no clue what that is for...... guessing interior harness/cluster?

i followed the dark blue and brown wires from the pcm nd they lead to the black connector as well. SO. my guess is i rip out all 4 and splice 2 with 2 then it will function properly right?

[EagleMark]

So i can take my fuel pump power wire, tie it into the relay, ground it amd toss in toggle then everything is holden with it?

Holdens are in Austrialia!

But golden... yes!

And since my t5 speed sensor is electronic (1996 camaro v6) (2pin) in theory it should work correct?

Probably? There is a flag to set for VSS not from DRAC. Accuracy is not important without E trans.

If there is only 2 wires, how do you jump it with 'b' being the test signal? And what wire goes to what pin on the pcm?

No jumping to read codes on 8192 Baud system.

[EagleMark]

also stupid question....... is the knock sensor the same thing as the electronic spark control unit? [esc]? research says yes and more research says no.

Older systems have an external ESC module used with knock sensor. Yours has ESC/Knock module in Memcal.

[Shawn1989]

Do you know what the gray container holding a chip with 3 purple wires coming out is?
ill post a few pics of my whole setup.

[Shawn1989]

1st 2 connectors are pcm, the other ones and gray box, i have no idea about


Pcm

[dave w]

I think the grey box is Vehicle Speed Sensor (VSS) converter, or Digital Ratio Analog Converter (DRAC) that converts 40 pulses per driveshaft revolution to either 2000 pulses per mile (2K) or maybe 4000 pulses per mile (4K) used by the digital speedometer, anti-lock brake module, or possibly even the radio.

dave w

[EagleMark]

Not a DRAC or VSSB, the gray box is a Fuel Module. It comes on HD vehicles and when engine is turned off it will run fuel pump for 20 seconds to cool TBI. Not needed...

The other three plugs were connected to vehicle harness, not sure about the big one, it looks like it plugged into dashboard or at least a harness to dashboard and possibly the DRAC/VSSB because of the twisted pair of wires is from VSS. The two small ones are for power... noted by Orange wires which are 12 volt power always, Pink would be Key On Power.

You know it takes many hours to redo a stock harness for stand alone use... have to get power, fuses, relays etc... all lined up. It takes hours of looking at wiring diagrams and laying things out one wire at a time. You need to tackle them one by one...

[Shawn1989]

Electrical, im used to....While tbi im not lol

i appreciate all of the help though, makes it ALOT easier being able to understand what i am looking at and have confidence reworking my first harness.

i work for a cab company building the cabs and making them function properly, so harnesses are nothing new. i build the cab from scratch in an 8 hour shift.

Also did all the electrical on the miata since it was nothing but a bare tub when i got it.... Im just not familiar with tbi, thats all.

The miata.
not the prettiest but it works. Lol.




what i come to every single day.... Finding a short in someones fuckup.


Then i make it look clean:


the final result:


so yeah, when i get all the info i need, ill feel confident with it because of my background....
not to sound cocky or anything. :)