V8 swap questions - CPI to TBI in a 95

[Gordon]

Ok so my van is a 1995 Safari with the crappy CPI 4.3L V6 and a 4L60E transmission.

My donor vehicle is a 1988 Chevy 1/2 ton with a TBI 350 and 700R4 transmission.

My main question is can i install the 88's motor and trans, use the 88's ECU and change the wiring according to Lockdocs writeup to switch to tbi?

I don't want to use the 4l60e unless i have to... which means i have to buy a new ECU.

I'm not sure if the wiring harness in the 88 truck is the same as the harness in my 95 van??

Second question is would the trucks gauge cluster bolt into the van allowing me cable drive speedo use?

Thanks, Gordon

[rlsllc]

viewtopic.php?f=8&t=188&start=0

[Gordon]

Ok so I got my 88 truck home... runs perfect and lots of power.

I'm going to use the TBI 350 engine, my 4L60E trans thats in the van now and i'm picking up a 95' ECU from a truck.

Should be almost 100% plug and play minus the wiring change for the TBI instead of CPI.

This truck even has the braided fuel lines

Anything else I need to know about this goofy 95 year?

Gordon

[Gordon]

Not sure how many people have done this swap but i'm having a BIG issue.

Got everything in and hooked up "exactly" the way Lockdoc did BUT if i hook injector 2 into A9 on the ECU it sprays sooo much fuel it stalls the engine.

The engine is a 5.7L from a 88 Suburban with a 2wd 700r4 trans.
Wiring is original to the 95 4.3L CPI engine.
ECU is from a 95 1/2 ton truck with 5.7L and 4L60E trans.

Someone please help me

Gordon

[Mr_Roboto]

Hey it looks like by the diagram I have that it should be in A9. I would probably get a meter and see if A)you have the right wire all the way through B)you have the right pin in the connector and C)Is the non-ECU wire connected to hot when the key is on? If it's on ground it would probably reverse the logic and you'd end up with something that would be on when it is supposed to be off.

[Gordon]

A- I have tried running a wire directly from the injector (green wire) to pin A9 with the same result.

B- Pretty sure I have it in A9 but i don't have a pinout or a plug diagram to verify. I have it in the "top" plug (short wire) on the clip side 9 pins down.

C - The white wire and red wire are tied together to a keyed 12v source in the harness and voltage has been verified with key on and running.

I even tried reversing the plugs on the injectors to make sure it wasn't 1 bad injector but it does the same thing.


The only thing the writeup doesn't mention is whether to use the stock 95 O2 sensor (4 wire) or the engines original O2 sensor (1 wire), right now its using the stock 4 wire.

I have even tried running the stock ecu with the 95 chip in it just to make sure it wasn't the driver circuits.

[Mr_Roboto]

Don't know if they changed it on the later vans, but the early connectors have the pin number/letter by them. Look inside the ECU connector. There should be a # there too. Is the problem "following" the injector when you reverse or no? It could be something with the injector its self or the fuel system otherwise if it is always the same injector.

ED:if it's always the same injector pop it out and check the lower O-ring. probably not in the right place.

[Gordon]

Figured it out... i have the connectors confused so i was plugging it into C9 instead of A9... ](*,)

[lockdoc]

I don't remember if I mentioned this but you need to use the SINGLE knock sensor that came with the 5.7. DO NOT use the knock sensors from the 4.3. Tape up the second knock sensor wire. The 4 wire O2 is correct.

[Gordon]

Yup only 1 knock sensor is hooked up, it's the OEM from the truck.

The 4.3 still has all of its sensors in it.


Lockdoc... YOU DA MAN

[Gordon]

Forgot to ask... how the heck do i set the base timing on this thing now?

Same as v6.. disconnect brown/grey single wire and adjust to ?? °btdc (i think it was 10° but im not sure)

Gordon

[lockdoc]

Set to 0*.

[Smiliesafari]

Gordon, I may have missed it, but did you change the fuel pump?

[Smiliesafari]

Gordon, I may have missed it, but did you change the fuel pump?

[Gordon]

Yup dropped the tank and installed a tbi pump.

Finally got all the wiring wrapped up last night and everything is working great.

Just need to set the timing now... it seems to be lacking power.

Anyone know if you can use the aldl port to tune the engine and trans?