740 turbo engine replacement newer engine swap
 

Hey guys,

I've been searching for some clarification on an issue I have at hand. A friend of mine has an '88 740 Turbo A/T, that suffered a thrown rod. Her ex wanted to be superman and fix it himself. In that, he replaced the enigne with a non-turbo engine, left connectors and vacuum lines disconnected, and fashioned intake tubing out of autozone quick enhaust tubing to join the turbo air box and system to the straight forward N/T intake. And couldn't figure out why it wouldn't run for more than 6 seconds.

Now, the Volvo still is in need of repair and I'm trying to line up all of my ducks in a row, and avoid pitfalls to prevent suffering the same failure as the aforementioned ex.

I have a line on a good 1991 740 turbo engine, manifolds, and turbo. I have been feverishly running parts interchanges on any and all parts that could affect this engine replacement. The two that worry me are the ECU and Automatic Transmission.

Will the AW71 in the '88 accept the '91 engine, without ANY modification? Or, will the '91 A/T fit the '88 chassis and associated electronics without modification?

The ECU for the '88 is: BOSCH #- 0 280 000 541 ; VOLVO #-1 367 487
The ECU for the '91 is: BOSCH #- 0 280 000 937 ; VOLVO #-3 547 781

I know that this typically indicates a different wiring harness, but I would like clarification. Will the '91 enigne bolt into the '88, and accept the wiring harness and vacuum system? And, what, if any modifications are required to make it so?

The proposed swap is a 1991 Volvo 740 turbo (A/T) enigne, into a 1988 Volvo 740 turbo (A/T) body, wiring harness, transmission, etc.

Help?

Thanks.

The 91 has LH2.4 and the 88 should be LH2.2. Some sensors are different...etc.

Wait for the experts to get on.

I was afraid of that....
 

I believe the LH2.2 ended with the '90 model year, and the LH2.4 picked up for '91. Just missed the boat I suppose. I would rather wait for a cute college girl (it seems every other one drives an 85-95 Volvo these days) to get in a fender bender with a pre-'91, and have her insurance company send it to the junk yard, and pull a LH2.2 engine, than to tweak a '91 to get it to work.

Thanks.

Any other insight is much appreciated.

Others have more experience with this.
This is a pretty good link: http://www.vcoa.org/700-900-faq/FAQSummary1.html
Tedv, bubba, adub96....etc might be able to assist when they get on.

if not, there is always trubobricks.com, brickboard....etc.

I think it requires the original 2.2 AMM and sensor from the motor being moved over to the new 2.4 motor.
The AW71 will bolt right up.