Alright i've got a bit of a special circumstance here, i have a 305 SBC in my volvo 740, the car was hailed as being a 92' 350 TPI, i've already disproven that w/ stuff like the MAF vs. MAP, the casting on the blocks backside showing 5.0, etc...

Best i can narrow it down this is a 86-89 TPI 5.0l motor, it has an automatic transmission that i'm assuming is a 700r4...

The wiring in this thing is just nasty... i can't make heads or tails of it, but i'm almost positive it's really messed up, so i came to this forum to try and find a complete detailed diagram for the ECM, i need to know the pin outs so i can cut the harness and build a new engine to ECM harness.

Anyway, so here i am, joined onto this forum to pick ya'lls collective brains since i've never played with one of these motors/ECMs before.

As it sits now the wiring is awful, in various states of decay, some of the places that are tapped into factory volvo stuff just doesn't make sense (like the MAF having taps into the headlights?)

I'm attaching a bunch of photos so that ya'll can see what i'm dealing w/, i hope to get enough info out of ya'll to where i can just make my own ECM to Engine harness to ensure there is no wiring problems in the future.



My Block Casting

 

ECM Module


ECM under the dash + wiring 1


ECM under the dash + wiring 2


Motor in the 740


Engine Bay Wiring


Unidentified plug coming off the ignition coil.


some vacuum solenoid i'm assuming, not a volvo part... also looks like it's not hooked up either...

 

Currently these are the symptoms it exhibits:

1. uneven acceleration, surging in power, you'll floor it and get all noise, and no acceleration...

2. uneven/unstable idle after operating 20 mins or so... wants to stall, will idle down really low and lope pretty bad...

3. transmission is shifting WAY early... like in 3rd or overdrive by 40mph (i can't tell what i'm in as the shift linkage isn't indicating right on the volvo shifter, just feel my way through it, i don't believe i can reach "1st" with the selector...

4. runs about 210 degrees...

Things i've changed or updated:
- Replaced the fuel pump in use with a holley 255lph high flow unit...
- Replaced the ignition coil, cap, and rotor...
- Flushed the entire coolant system and put in new proper mix fluid...

On the way in to be replaced:
- MSD 8.5mm wires
- BBK adjustable fuel pressure regulator
- Thermotech or hypertech (forgetting which) 160 degree thermostat

What the car is supposed to do:
This is supposed to be a fun daily driver, with the 305 we figured a low 13 second car should be pretty easy, especially since this volvo's curb weight is 3300lbs now, which if what i read was right, makes this setup lighter than the f-body it came from...

 

sorry about the small images... pulled stills from a video i've shot to try and catch the stuff i'm talking about...

 

up

 

I see a few potential issues with your setup.

Mass Air Flow Sensor Location
In my S-10 had my MAF in a similar location with several bends before the throttle body. I kept getting MAF trouble codes and replaced the sensor three times with no success. I got tired of if and converted to speed density...no problems since then.

Transmission
You should have a TV cable running down to the transmission. I'm not so sure how it will shift properly without one. If you have a 4L60E and an aftermarket controller, then that's a different story. The 700R4 has a white (somewhat square) connector on the driver side. The 4L60E has a round gray connector on the passenger side.

Engine Operating Temp
With the 160 degree thermostat, I would think you'd be running cooler than 210. With original programming, the ECM turns the electric fan on at 226.4 F and off at 221 F.

About your unidentified connector
That wire coming off the gray coil connector goes to the tach.

 

I'm always hesitant to mention this (moderator let me know if this is unappropriate), but I build new TPI harnesses for both the mass air and speed density systems.

Assuming there is nothing wrong with your engine (or sensors), you would only have to connect three wires to get the engine running (battery, ignition, and fuel pump). The grounds are all terminated to one ring terminal and bolt to the back of the driver side head. There are other wires to connect for additional functionality, such as:

• Electric Fan(s)
• Brake Switch for TCC Lockup (700R4)
• Speed Input to the ECM (not optional...you need this)
• Park/Neutral Indicator switch (700R4 only)
• Service Engine Soon Indicator (usually goes to the gauges)
• A/C (I include the dark green A/C On input wire for you to connect to your existing A/C wiring)
• Oil Pressure Gauge signal wire

I would recommend converting to speed density. By the time you sell your mass air setup (165 ECM, MAF sensor, ESC module), you'll pay for the conversion costs (730 ECM, knock sensor, and MAP sensor). The speed density system has fewer wires and fewer relays.

I can build you a new harness for less than the cost of a Painless harness (under $300.00). I use the same wire, connectors, and terminals as Painless. I also have used 730 ECMs for speed density conversions. I test every harness on my TPI test engine before shipping. These ECMs are very common in the junk yard or you can buy one from me for $40.00.

Below are pictures of my harnesses. These are my stand alone 4-foot (distributor to ECM) harnesses. I often build custom length harnesses.

Mass Air


Speed Density


Notice I used standard automotive (bosch style) relays with the speed density harness. If you want the relays inside the vehicle, I can use the less expensive bosch style relays, or if you're mounting the relays under the hood, I can use the GM weatherpack relays.

Vehicle Antitheft
I can integrate the VATS bypass into the harness as a removable module. I can alternatively remove VATS from the prom. The benefit of the bypass module is that you can use it as an antitheft device by unlpugging it to disable your vehicle. Here's a pic.



Emissions
I see you've removed emissions. If you convert to speed density and decide you do not want to have the prom reprogrammed, I can bypass emissions with these modules.



Deciding whether to have the prom reprogrammed
If you are converting to speed density, you need a memcal anyway. Your local GM dealer sells these for about $100.00. If you are okay with the original fan temperatures (ON @ 226 / OFF @ 221), then I can include the bypass modules for VATS and emissions. If you want the fan temps lowered, you can have the prom reprogrammed to remove VATS, emissions, and lower the fan temps. I am able to do this.

Vehicle Speed Sensor and 1227165/1227730
Keep in mind that the mass air ecm needs a 2000 pulse per mile signal and the speed density system needs a 4000 pulse per mile signal.

The Wiring Pinouts/Diagrams You're Looking For
http://home.earthlink.net/~gellett/89wiring.gif

I'm not trying to push you to buy a harness from me. I'm just showing you how I can help and providing you with the information you asked for in this post (wiring diagram).

Judging by the harness (the two weatherpack style relays) and the front engine accessories, I think you have a 1989 system. If you do not have a 9th injector (cold start injector), then you definitely have a 1989 engine. If you do have the 9th injector, you have a 1988 engine...but I think it's a 1989.

 

How long have you been building these kits?

And how would you go about getting this 2000 or 4000 pulse per mile signal? the volvo instrument cluster gets it's speedometer signal from the volvo rear end, some sort of pick up back there...

 

The VSS signal comes from the transmission or the back of the speedometer. In your case you'd need a trans mounted VSS. you can use that with either the MAF or SD setup. with speed density it goes directly in to the ECM, with MAF it would ned to go to a sperate box ( damned if I can remember the name lol.. have one sitting in the basement) they came on the 90+ cars with TBI .

My 88 has thos weather pack relays.. my 87 didn;t