General Low High-end Power -- Lower Smoke too

[ludicrouslarry]

I have had power problems with my Multipla. It is noticable in higher gears as it limits my top speed and causes a lot of downshifting on medium sized hills on the highway. I sit there with gas pedal floored without power. In fact I can pump the gas pedal in the top 2/3rds of it movement with no change in power (no surge in power or engine RPM). Generally need a VERY flat space or downhill to get the engine >3000-3100 RPM. I can get there easily by down shifting--- but no power. I do not have the problem that most people say comes with the dirty EGR valve. In fact, I have less smoke than I had before.

The STRANGE thing is that I can sometimes overcome this problem. If I am on an upward grade and have the rpm around ~3000 RPM with the gas pedal fully pressed (the pedal to the medal= as the saying goes) it might fix itself--- I get a noticeable surge in power and the RPMs climb. As long as I keep the gas on I can climb through the gears with this normal powered engine. I can keep the power by keeping the RPMs >3000 if I do not need to upshift or go faster. However, if I am behind a car and have to slow down (take the foot off of the gas), I once again have an underpowered engine. The procedure described above to get the engine to break free does not always work (in fact, it seems to be getting harder and harder to get it to work).

Does anyone have any thoughts on the cause? It should not be the fuel injectors, because I run a deisel injector cleaner additive with every tank. I have also changed out the fuel filter, but that made no difference.

 

[widemouthfrog]

Power falling off on long inclines - sounds like it could be the MAF. Have you tried cleaning it?

 

[ludicrouslarry]

I never followed up posted on this. Sorry gents!

WideMouthFrog, you were right on!!! I opened my air filter to get at my MAF and my air filter was all blown in. I gave the Mass Air Flow sensor a much needed cleaning with about 3/4 of a bottle of MAF cleaner, replaced the filter, and bolted everything back together. Viola- the power was back to stay!

 

[youngman28]

I opened my air filter to get at my MAF and my air filter was all blown in. I gave the Mass Air Flow sensor a much needed cleaning with about 3/4 of a bottle of MAF cleaner, replaced the filter, and bolted everything back together. Viola- the power was back to stay!

hi, i am newbee here. my old multipla y2004, gave me the same problem as u descrip here. due to lack of power, i try to un plug the MAF,open up the casing cover air filter,take out the filter, take out the 2 screw connect the MAF and casing, now i can see the MAF, but cover by a corse plastic net (on RHS), try to dig out the net, but lock it firmly, try to loose on left hand side, the MAF and plastic ducting was firmly tighten by a steel belt, can't find any screw to loose it?, any one here can give me a guide how to do it? my intention is to spray some MAF cleaner to clean up the sensor.

Btw, have plug-off the MAF temporary, and test run on highway, the power was came back. Any side effect to the engine in long run?

 

[momoe]

Theoretically, you will get slightly less mileage as the MAF measures air mass (to allow for differences in altitude and temp) and that information is used by the ECU to adjust injection timings.
In practice it's all relative, if the MAF was giving erroneous data to the ECU which made the car run badly, the the default setting (without the MAF connected) may well give better performance.