I just finished up my AW70 to M47 swap in an 88 245. I had no problems with the transmission, it was in my daily driver for the last 5 years. The wagon I swapped the tranny into I just purchased a few weeks ago and have not drove much. I bought it cheap because it had transmission issues, so I figured the swap would solve the issues. It was slipping in gear and randomly losing power on acceleration. (losing power as in press on the gas and get no response. Occasionally it would slip and rev higher but not accelerate.)

After two long days and a lot of cursing I finally complete the swap, complete with a new clutch. The initial test drive was great -- no problems, yet I only drove the car around the block. Later in the evening, I took the car down to the grocery store and while accelerating in first gear, the car lost power. It didn't rev higher, just lost all power. When I shifted into second gear, it continued driving fine. When I left the grocery store, I had the same problem. Lost power* in 1st gear at about 2000-2500 rpms (no tach installed yet, just a guess) and shifting into second brought it back to life. The clutch feels good, but does need an adjustment, as it engages when my foot is almost completely off the pedal.

My issue is trying to decide if this is a clutch issue, a swap mistake issue, or an underlying issue with the motor/electrical that needs attention. Any advice would be greatly appreciated, as I am ready to enjoy my new ride!

*note* By loss of power, I don't mean the car dies, it just loses acceleration power.

 

New through out bearing?

clutch return spring on?

Does your transmission have that weird rubber coupling?? installing it wrong causes a few issues....

Type F fluid on the tranny?

Does your pressure plate have 4 springs or 8 springs?..for older Volvo's is 4 and Newer is 8 springs on clutch...

 

forgot to mention....

my clutch engages half way when pressing the clutch.....sometimes it feels as if it slips a bit after a long driving period and hit stop and go traffic....

my sincro rings is what I wanted to change on the M45 but ran out of cash....

 

Answers:

 

After driving the car around a lot the last few days, I have an update that may help diagnose/explain this issue better:

The car only loses power in first gear.

Now the interesting part,

The car only loses power in first gear at 1500 rpms one time after starting. So if I turn the car on, put it in gear, and take off, at 1500 rpms the car will lose all accelerating power. If I shift into second, or let the rpms drop down to about 800, power resumes as if nothing happened. No matter how many times I stop and go in traffic, this issue will NOT repeat itself. If I stop at a store and turn the ignition off, when I start the car back up and go into gear it will once again lose power in first gear at 1500 rpms.

 

Did you move/rotate the fly wheel when doing the tranny swap?

Adjustment:
Cable actuation----free play at release fork................1 to 3 mm or (0.04 to 0.12 in)
or do you have hydraulic system?

my books tell me something with the timing being out a bit and not the transmission...

 

It is cable driven. I will check timing with timing light tonight. Good suggestion!

 

Timing was bouncing between 11 and 13 degrees, within the tolerance of 12 degrees. I did find it a bit unusual that the timing mark was moving around, I don't remember it bouncing around on any of my other volvos.

Also, I replaced the flywheel.

 

How about your crank pulley o-ring? going out on you?

I would go through the timing again to make sure....but I am at a loss on this...
I was worried of moving the flywheel as I was reading on my books to take note on the 15 degree crap/mark odd positioning of it...based on certain marks to the engine or something like that......I just left it were it was and did nothing to it...but thinking about it, this won't be your problem..

 

Still struggling with this...grounds seem good. It is very unusual, never seen this problem with a 240 in years of driving them. It's not being in 1st gear that causes the problem. If I start it up, and step on the gas in neutral, it will momentarily cut out at 1500 rpms and then drive perfect until I turn it off again. So whether I'm in gear or not, the first time the car reaches 1500 rpms it cuts out then drives perfect until I turn it off...

 

your problem isn't the transmission then...but you know that now.

Check it out:
ENGINE STUMBLES ON ACCELERATION
1: Spark plugs fouled
2: Fuel injection system malfunctioning....FPR going, intank pump going, main pump going
3: Fuel filter clogged...cheapest fix
4: Incorrect ignition timing....
5: Air leak on the Intake somewhere

ENGINE LACKS POWER
1: incorrect ignition timing
2: excessive play in the distributor shaft
3: worn rotor, cap, wires
4: incorrect gapped spark plugs...or plugs done.
5:
6: Faulty Coil SWAP YOUR COILS TO SEE IF YOU GET AN IMPROVEMENT
7: Brakes binding
8:
9: clutch slipping
10: fuel filter clogged
11: emission control system not functioning properly...check your O2 sensor...
12: Low or uneven cylinder compression pressure

I colored the numbers that I think could be the problem areas.