Do I have a MAF sensor?

briguy1960 · Post by **briguy1960** » 11 Jun 2008, 00:29

Hopefully not a total idiot question. I've owned probably 8 volvos over the years and am just getting into LH jetronic. I have a made in Sweden /assembled in nova Scotia 1992 740 that I have owned for a couple of weeks.

Off the line acceleration is abysmal by any standards but the other day the thing would not go faster than 10 mph Long story short. I cleaned what I thought was the MAF sensor ahead of the air box. Weird though the MAF does not look like any I have seen before it is very compact. i.e. four small openings in the airstream but no visible wires or venturi. I've seen MAF sensors on many other vehicles and they don't look anything like what I got. What I see protruding into the airstream is not much bigger than a chicklet. Am I missing (literally) something that should be attached?

Any guidance appreciated

1992 no turbo 740

TIA

B

Post by **MadeInJapan** » 11 Jun 2008, 06:45

I don't think you cleaned the MAF...you cleaned something else. Here's the diagram for fuel system under your hood...see if you can find anything else that looks like what you cleaned (#16 is the MAF in the first diagram and #19 is the MAF in second diagram).

Actually there were 2 basically different designs for your model year...2 that look somewhat identical and one called "Regina." The first diagram above is most likely for your car but I also posted the other one (I believe it's the one for a turbo so it might not apply) just in case.

briguy1960 · Post by **briguy1960** » 11 Jun 2008, 11:56

Thanks for posting those images. Referring to the first jpg. I do not have the part #16. But I do have parts 17,18,19. Is this the Regina system? What are those parts? Do they constitute the same function as part 16. This is where I sprayed the DeOxit cleaner. On the ignition test point on the computer (socket 6 I was getting code 1-4-4 which is signal from MAF to ignition ECU. I cleared the codes and it runs knda OK but still very slow off the line.

TIA

Brian

Post by **MadeInJapan** » 11 Jun 2008, 13:21

Brian,
Just from knowing these designs...really don't know your car...I just posts whats I gots...I would think that the large cylinder is the MAF housing and the smaller piece is the actual sensor so you did spray the right one. You might try it again but if it's really dying then you might not have much luck. I know that many of these early RWD's use the same parts (part numbers are included in the diagram) so you might try a junk yard first and then a parts distributer...last resort I guess is the dealer. Good luck.

Oh, another thing...you might still have a stored code...unplugging your battery for 10-15 minutes might help her run better. Btw, I know nothing about the Regina...what was it? Named after some Swedish guy's wife or daughter or something?

briguy1960 · Post by **briguy1960** » 11 Jun 2008, 23:17

Well according to some other sites I cam upon Regina was another Fuel Injection system that used a MAP (Manifold Air Pressure) sensor rather than an MAF. The sensor where the MAF is in the Bosch systems is actually a temp sensor.

I cleared the codes and and it seems to be running OK.

Always lots to learn.

Thanks for your input

B