Sorry guys, this is probably a story that sounds like an old horse being beaten! But so it is.
I swapped a 97 white block I think they're called, into a 96 body. Both are 850 turbo wagons. I replaced many new parts; coil, distributor, rotor, wires, plugs, pcv system, timing belt kit with water pump, head gasket, valve stem seals, cam sensor, crank sensor, to name a few. I know some of the wiring has to be part of the problem, but I have been working through that. The OBDII states no codes, it shows ambient temperature for the engine so I know the temp sensor is working, when I crank it over it shows rpms, so I know the crank sensor is working. The dash shows all the lights including the check engine light, I have heard that if you have that you know the ecu has power. I have set the cam marks on the "V's" and the crank mark is spot on it's Mark, however the rotor is in-between the #4 tower and the #1 tower. I have spark and I have fuel and I think I'm timed. But no start. There are no Volvo enthusiasts in my area, Watertown, NY. The knock sensors are not connected, but I was told that that would not effect the starting. I have spent too many days looking in the engine bay, reading on line schematics with no gain toward the goal of actually enjoying the car. Before I removed the first engine, the windows worked, now they don't, nor does the blower fan, so something's not connected correctly. Would the no start circuit part of the security's system cause something like this? Or would it just not turn over at all? Please help me guys!!

 

Did you swap over the ECU from the donor car or did you retain the original one from the 96 body? I'm not sure it would make much of a difference but it's worth investigation. Best of luck to you.

 

Yes, I have them both, when I have the recipient ecu's installed, the OBDII fails to connect with the vehicle. Says reading error. When I have the donor ecu's installed, the OBDII connects and appears to function properly.. Says no codes. I get temp reading and rpm reading when I crank her. But still no start with either one.
Thanks Luke, I appreciate the response I continue reading the 678 pages of older post threads, learning more as I go, but it's encouraging the recieve live interest!

 

I don't know of anything on the engine itself that would interfere with the computer recognizing which engine is at the end of the wiring harness. The harness plugs into various sensors that give a signal. The only thing that I am wondering is whether the flywheel crank sensor pickup is different between the two models.

 

I didn't keep the vin from the 97 so I don't know if there is a difference between these engines, they looked identical. Does anyone know if there is a difference between a 96 850 Turbo wagon and a 97 850 Turbo wagon? Thanks Tony.

 

The VIN on the 96 chassis shows a 57, indicating a B5234T. So that's the engine that I removed from the car with the transmission. The ID on the block of the 97 engine I installed ,with it's transmission, states that it is a B5234T. So it is the same engine. And I have installed the ECU and the transmission control module from the 97 donor that drove before the swap. I have the old flywheel sensors from both engines, I will try both those and see if one of them is the magic key! Thanks for the suggestion, I appreciate the sage wisdom that comes from experience, after all, it's knowing where to tap with the hammer that counts!

 

The alarm no start function will keep it from starting. When you try to start do the flashers go? On my 95 it wouldn't start until I locked and the unlocked the doors to shut off any alarm functions. How do you know you are getting fuel? What kind of fuel pressure do you have? Last how do you know you have spark?

 

Thanks for the reply, no the flasher's don't come on, I have locked and unlocked the doors several times with the fob. I didn't have spark until I replaced the coil, however it wasn't and isn't enough to light the spark plugs tester I bought. When I short the coil wire with a screwdriver to ground I get a good spark. The fuel, I can smell gas pretty good when I turn her over, there is spray at the Schrader valve when I press it. I haven't checked the pressure yet but just found out you can use a tire pressure gauge, so I will do that soon. Everything is new, plugs, wires, distributor, rotor, coil, fuel pump, fuel filter. The headlights come on wherever the ignition is in the #2 position,is that normal?

 

I'm not sure why you changed engine computers.

 

did you confirm the injector relay (up front by the radiator) has good connections and is actuating?

 

I talked with the service manager at the closest dealership, he said to leave the ECU from the 96 in the car. I did. Of course it didn't start and it would not connect to the OBD2, it always said "reading error". I had never drove or started the 96, I bought it in a non- running state. (Impluse buy, never good) I like to blame it on Robert's YouTube channel, it gave me the confidence that I could do this. So the 96 ended up being seized, er go the 97 swap. The 97 I drove, it ran well, and everything worked. The body was excessively rusted from the salt on our north country winter roads.(Watertown, New York)
Not knowing what else could be fried on the 96 I tried the ECU from the 97. It at least could be read by the OBD2. I figured this was progress. I of course bow to your experience and knowledge, my vocational automotive training ended in 72, before sensors and computers were involved. I am eager for any suggestions. Thanks.

 

Ok, it may be late in the game to suggest this but I will anyway. A method that has never failed to help me with a no start issue is starting fluid! I spray a good 2 second shot down the throttle body intake, and try crankng her over. If she tries to run or uns for a couple seconds and dies, you know you have a fuel delivery issue. If it does nothing, try another 2 second shot of fluid. If still nothing, you can assume you have a timing or spark issue to deal with. May seem like a step back from where you are at troubleshooting right now, but it can't hurt and just might help. Good luck!

 

Another thought, have you checked the compression to make sure the rings and valves are ok?

 

QUOTE=mt6127;464268]did you confirm the injector relay (up front by the radiator) has good connections and is actuating?[/QUOTE]
First, thanks for the response. I have checked that it is a good connection and it has two hot leads, I have not checked that it actuates, however, I am getting a strong fuel smell and see vapor coming out of the turbo return when I turn her over with the air filtration box removed. So I assume it is getting fuel. When I try to start her, she doesn't even sound like she's trying to start, then when I get off, I hear what I assume to be fuel burning up in the exhaust, soft ,small, slow not even but almost pops. To me I think the timing is advance or retarded. I check the timing marks again, cams are on the mark and the crank is on the mark, so what am I missing? Something I'm missing. Thanks for any help, friends said I was too old to do this, I've come this far through the heavy work, but it seems I've a way to go yet.

 

Good suggestion. I did try this early on in the process, before I replaced the coil, certainly wouldn't hurt to try that again. The compression was 130, 120, 150, 130 and 130. I shot some oil in just beforehand, might be why 2 & 3 were different, don't know. Good reminder thanks.

 

I had a 2001 V70 XC that was super clean and we bought it INOP. The turbo let go and the engine lost oil pressure.

We sourced a used engine and plugged it in. It cranked right up.

I keep going back to why the original computer was changed. There is nothing on a model this old that would tell the computer that the wrong engine is in place. You should be able to communicate with the engine computer even if every sensor is unplugged.

Before spinning around anymore on other things, you need to determine why the original engine computer cannot communicate with the scan tool.

 

These are from the car the 96. This does not read.
These are from the donor car that the swap came from. The 97. This reads.
Thanks Tony, do you have a suggestion as to how I can do this? I am obviously in over my head.

 

The computer on the left is the transmission computer, thus the Aisin name on the box. Are you changing both computers or one?

 

Looks like the 97 has both different ECU and transmission control modules. than the 96. Might be stating the obvious, but........................

 

FYI - the poster and I had a conversation. I recommended that he use the computers from the 1996 model and be certain that the computer modules were firmly mounting in the pin pad. I suggested that he spray the area down with silicone spray so that the plastic components slide easier and make sure that both computers draw down on the pin pad connectors.

I believe that the spotty communication is due to improper pin contact.

Next, I advised him to recheck his cam and crank timing marks.