I bought my 740 turbo wag a few months back with 155,000. I am now having a problem with it bogging down in snowy weather. I live in Minnesota so this is a problem. It actually is now bogging down after I shut it off from a short 2 mile trip in the cold. It initially happened at freeway speeds whenever I tried to engage the turbo. It ran fine until I put the gas down enough to engage the turbo, then it bogged. Then, once I got off the highway and had to slow down and stop, it completely bogged and I almost didn't get it started again. If I let it sit awhile, then it starts up again.
I live in a small town of 1800, so needless to say there isn't a Volvo dealership or even a foreign car mechanic shop. My local guy thinks it may be a moisture problem seeing as it initially had the problems when the snow was flying. He thinks changing the distributor cap is a good first step.
Has anyone had this problem, or does anyone have a better idea for a fix. I can't afford to finance a long process of trial and error.
any help would be greatly appreciated as I go to the mechanic this afternoon around 4:00.
Thanks,
jason

Hi Jason,

If it is moisture related a good first check would be the plug wires. I ran into the chugging and bogging issue with my 86 744 (non-turbo). Plugs, wires, cap, rotor and also check how clean the coil is on the passenger firewall. It is my understanding that a minor current leakage can cause strange performance issues.

Greg

If it happening anytime you engage the turbo, it is likely a turbo hose leak. Either one came off, or there is a hole in one.

Good luck!
-Eric
'89 765t, 196k
'93 944t, 122k

No expert on 740s, but it sounds like you are flooding out. It could be the AMM, which regulates the amount of air coming into the engine. All the turbo does is force more air to be mixed with the gas. Check the air cleaner for leftover leaves, etc. Throttle body might also be a bit dirty.

Klaus
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98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)

What is an AMM?

Sorry, I am no Mechanic.
jason

I am not a mechanic either...

Air Mass Meter. Regulates the amount of air that can flow in to the engine. Kind of like a butterfly valve which needs to be open when the engine is warm. It is a common fault and easily fixed.

Borton Volvo is pretty good if you tell them to keep the repair bill cheap. Just tell them you are a struggling college student without an income :)

Klaus
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98 V70Rawd(101Kmi), 95 854T(85K mi), 75 164E(173K mi)

air mass meter. aka mass airflow sensor. should be right after your aircleaner.

I am in the midst of troubleshooting the same issue my 740 Turbo wagon. Are you blowing black smoke when you accelerate ? If you are, it might be the AMM. Shut the car off and unplug the AMM Electrical connector, take the car for ride, swee how it runs, if there is NO difference when the AMM is unplugged then you might want to try a new AMM or have a Tech look at your codes to see if the AMM has gone bad. It's not a big deal to have someone look at your codes, even if you do live in Frostbite Falls, Minnesota.
--
Rich George