I'm in the middle of repinning for my 7730 conversion, and I've a question on the MAP sensor wiring. Please see the following thread.

https://www.thirdgen.org/messgboard/...ML/001516.html

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408cid 1985 Corvette
http://www.mojosgarage.com

 

Just use that diagram that Brent supplied to you, best thing to do is get a plug that goes to the map sensor(as if you could do it any other way). Then find out which pins go where by using Mike Davis's site, he has already did most of the work by typing all of the pin changes out.

Brendan

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1987 IROC-Z L98,SuperRam,EB 6085's,LPE 219/219 Roller, Crane 1.6RR, EB TPI Base, 58mm TB, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, MSD 6AL, MSD Blaster 3, Aluminum DS, 94 Disk Rear, Adjustable Valve, Precision 3.73 Gears, Sub-Frame Connectors, Hotchkis Lower Control Arms, KYB Shocks/Struts, Suspension Techniques Lowering Springs, Polyurethan Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm,

To see the ROC, Check out the webpage Here

 

I'm toward the end of the pin changes now. The injector wires need to be spliced together and moved still, the 870 had 2 wires per bank. There are a couple of other stragglers, but most of what's left requires a little more than simply changing the pins. I'm on my way out now to buy some wiretaps. I stopped last night when I started getting too tired and making mistakes.

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408cid 1985 Corvette
http://www.mojosgarage.com

 

I wish i could give you some pointers but i did the easy swap(165 to 730).
Let us know how it turns out.

 

I'm down to the VSS, Map sensor (I'll be hijacking the signal wire from the MAF, and splicing into the TPS for the MAP +5 volts reference and ground.), and the knock sensor change. I'm waiting on some info on the VSS wires to make sure I'm getting the correct signal to the correct place. Should be finished this week!

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408cid 1985 Corvette
http://www.mojosgarage.com

 

Careful,
you just can't mix and match power and grounds on the 730. the way they share power is very specific, and if you get it wrong will take lots of time to sort thru. Do the 5v and ground sensor stuff exactly as the book shows. EXACTLY
I had one that another guy did that took me days to figure out, was a real PITA.
Had a 747 car that just never was quiet right that was also the same thing

 

The problem is getting new wiring through the firewall on the Vette without pulling the engine. Bowtye8 suggested grabbing the TPS power, that's what he did on his '85. I could get the ground from the old MAF connector and repin it to the MAP ground in the harness, but the 5 volt lead goes through the burnoff module, and I don't even want to mess with that.

 

Mojo I am doing the same thing as you and am just waiting to burn my chip. I just wanted to ask about the 5 volt reference Voltage!

I Fed a new wire from Pin BA5 on the ECM and ran it straight through to the MAP sensor connection C.

I think this amy be wrong or is it okay? Does the ECM produce it's own 5v reference voltage on this pin to the MAP? Or do I have to connect it to the TPS 5 Volt reference?

 

According to my diagrams, BA4 is +5v ref for the MAP, BA5 is +5v ref for the TPS. Since you're running a new wire for the MAP, I'd run it to BA4 and leave BA5 for the TPS. I have to tap the TPS +5v because it's next to impossible to get another wire through the firewall on my Vette.

 

I just ran my wire where the speedo cable enters into the interior. I know it is not a neet thing to do but was much faster and easier than trying to feed it through the firewall.

 

Yep I made a mistake BA4 is the MAP refernce +5 voltage.

 

There is also a way to use the current knock sensor. Email me if interested in this. Also the buffered VSS data from the cluster and you don't have to change the prom.

Jason

 

What do you have to change in the prom for the vss?

 

Wow--old topic

When I repinned my 870 for the 730, I kept the stock VSS from my 85 Vette and used the stock settings in the AUJP BIN for the VSS.

So I didn't have to make a change in the PROM. There is some Corvette specific wiring for the VSS though since the F bodies use a mechanical-drive speedo and the Y bodies use an electric signal to the cluster.

 

Actually I have an 87 formula that came with the electric speedo. So I guess the only wiring changes other than a repinning will be the map sensor.The reason for digging up this post is I'm going to swap to sd.I might do it this weekend.What about that 5 volt feed to the map?Could'nt I just use the maf 5 volt wire from ba4 to the map.It's in the harness so no need to run new wires,right?Other than these simple questions I'm ready to swap!

 

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Could'nt I just use the maf 5 volt wire from ba4 to the map.It's in the harness so no need to run new wires,right?

That's exactly what I did. I got the idea from Dennis (Bowtye8), he did the exact same thing.

 

I did a conversion on my camaro. I traced the wire from ECM to Relay then relay to sensor and soldiered them together.