Troubleshooting 740 Regina Fuel system( was do I have a MAF

[briguy1960]

Well after a lot of poking around I've come to the conclusion I do not have a MAF sensor but instead a MAP sensor located near the brake booster, connected by a light brown vac hose.

Hard Starting (sometimes) non existent acceleration below 2500 RPM (Sometimes) Seems to vary every time I star the car. No check engine and since I cleared the codes I get 1-1-1 on test terminals 2 and 6. Beyond 3000 rpm it pulls strong and even. No pinging , smoke or bad smells.

Here is one possible clue. With the engine in neutral I revved it up to 4000 rpm and then slowly backed off on the accelerator. At a certain point the smallest movement caused the revs to fall from around 2600 to around 1200. In a carburetted car I would call the characteristics exhibited a flat spot.

This leads me to believe the TPS may be the issue. Apart from the coolant temp,ambient airtemp,MAP, Lambda sond and TPS are there any other sensors imputing info into the ECU?

This weekend I'm going to take some de-oxit cleaner and clean the MAP and TPS connections and see if it helps.

Any other ideas?

Also, is there a schrader valve somewhere on the common injector rail or do I need get something special to test pressure

Finally, I tried to hear the fuel pump. Both by sticking my ear to the filler neck and by sitting in the car with everything of and moving the key to the ignition position. I could not hear anything except clicks from the relays. But surely it would not run at all with no running fuel pump ---right.

Finally, if I cannot solve this can anyone recommend some Volvo shops around Vancouver BC?

TIA as always

Brian