Rainy Day Start Problems Regina/Rex 1990 740 Volvo

Hello,
New to the forum. Can't wait to get started. We have had lots of Volvos in the past from 1960 544 to our latest 1990 740 Regina/Rex Wagon. This 1990 is the first we've had with so many sensors and computer controls. Have played around replacing parts and brought it from a shaky shaking, rough running, gas guzzling disappointment to 11.5 Km per Liter, smooth running, joy to drive vehicle. We have what seems like one last issue that we would like to solve.

On rainy days it will start OK, but you can't touch the accelerator without it just about dying. In fact, it will die if you press the peddle for any more than a second or so. It takes just a minute to warm up and the problem goes away and car runs perfectly. So far, we have replaced the following: MAP, O2, Radio Suppression Relay, IAC, Fuel Pump and Relay, Manifold gasket, Engine Temp Sensor, Various vacuum hoses. Spark plugs and wires (BeckArnley?)

We haven't replaced the distributor cap and rotor. Could that be it?
We would be most appreciative of any help or ideas.
Many thanks in advance
Lonelydonkey

probbaly the map sensor. its the same one a 2003 chevy venture van uses. about $40 in the states. if its only doing it when damp it may be the connection. i would start there

boosted12a said:

probbaly the map sensor. its the same one a 2003 chevy venture van uses. about $40 in the states. if its only doing it when damp it may be the connection. i would start there

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I think a few chevies have the same one, I got one by having the guy pull up the part # for a cavalier with the 2.2

Stiggy Pop said:

I think a few chevies have the same one, I got one by having the guy pull up the part # for a cavalier with the 2.2

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dosent suprise me. only reaason i know about the venture one being the same is because i have a venture and used that known good map on my 940

Thanks Everyone - will look into connections. Got a new map sensor, but problem persists.

What about the cold start injector? That injector only works when its cold.

I've never had this issue with Volvo spark plug wires, but years back with cheap wires or wires that were old cold running was poor. When things heat up, issues with wires went away. So, maybe check your high tension wires, if visibly cracked, time for a new set. I'd avoid the chain store crap, and get the Volvo (Bougicord?) from somewhere if it turns out this is the issue.

Maybe you have water leaking on your head mounted distro. The rubber under the bonnet near the windshield has the tendency to work itself loose.

Check the dizzy for oil in the cap. I had similar issues and it was the humidity screwing with the oil leaking into the cap