Weird sound, mad shaking and stalling?

CRDburnouts · **Posted:** Wed Jan 21, 2009 1:22 pm

My MAF 'somehow became unplugged' and finally made itself known to me :wink:

I went to start my jeep, the temp was around 20 and it started, went to 1kRpms and had a bad stalling sound every second or so. It was shaking so bad by mirrors were vibrating. When I put it into reverse it stalled. I wanted to see what it would do driving so I took it less than a mile and it had no power, It felt like the engine wasn't getting air or something. I plugged the MAF back in and it seemed fine.

Any explainations?

ATXKJ · **Posted:** Wed Jan 21, 2009 1:51 pm

Did it repeat? -

I mean can you cause stalling - by unplugging the MAF sensor?

because these beasts to occasionally exhibit the stalling behavior that seems to be cured by turning it off/on.
that would have nothing to do with the MAF.

(Those generally relate to some sort of fuel delivery problem - air leak/clogged filter ect)

CRDburnouts · **Posted:** Wed Jan 21, 2009 2:01 pm

Up here in the mountains I feel like an inactive EGR has no benefit. Unfortunately I have a 1 mile drive to work so that can't be good on my motor, i always warm it up 2-5 minutes before I put it in gear but that still horribly inefficient. My mileage dropped 8mpg when I dont drive long distances. I think the problem had something to do with the MAF so I'm going to leave it plugged in for now. It was really weird that it had not happened before like when it was -9.

gmctd · **Posted:** Wed Jan 21, 2009 2:55 pm

Unfortunately that 2 x 1mi drive\day is prolly killing your KJ - worst soot-emission is cold-weather idle to hiway speeds with cold ECT and IAT - hiway speeds are required to generate EGT's high enuff to oxidize, or burn-off, the accumulated soot in the soot-trap\oxidizing catalytic convertor - restricted intake airflow is resulted from restricted exhaust flow - restricted intake airflow = low power

dtempler · **Posted:** Tue Jan 27, 2009 8:28 pm

Interesting read, I had similar issues. I originally unplugged my MAF sensor because I am having poor running, no power, and stalling problems at start up until I get going (clears up about half a mile from home). I wanted to see if the problem was EGR related. When I first tried it the temp. was about 0C (24F). The problems seemed a little better but not completely gone. Shortly after, 2 days later, the temps dropped to -25C (-10F) and the problems seemed really bad! It barely ran for the first mile. It also sounded louder and really rough (compared to funning it at this temp. with the MAF plugged in). It wanted to stall as soon as I put it in gear.

I have now plugged the MAF back in and will start trying to eliminate the possibility of air in my fuel system. I do get bubbles every time I bleed my fuel head but I don't know how much is too much. I have also found that my fuel heater plug is leaking so I will start by changing to the new filter head since I need a new one anyway.
If I am still getting air in I will replace the plastic connectors near the tank with rubber hose and clamps. Hopefully before I burn out the new filter head. An electric lift pump will be my last resort.

Any ideas why it runs so rough in the cold with the MAF unplugged? Could this be related to the air in the fuel problem?

ATXKJ · **Posted:** Tue Jan 27, 2009 9:36 pm

you have to fix the air in fuel problem 1st - because that will definitely cause problems.
the correct amount of air bubbles is none, the plunger at the head should be solid.

mine always runs better in ORM mode - I don't do the -10 stuff (and I still don't care if it's C or F)

warp2diesel · **Posted:** Wed Jan 28, 2009 12:21 am

...because you are getting more oxygen in the cylinders. The EGR is to reduce NOX emissions (the boogie man gas) that can cause smog. In reality it is almost impossible to happen in BC or most of the US except for LA, Las Vegas, Phoenix, Chicago, Toronto, or Manhattan on a very hot day, with no wind under perfect conditions and it takes a lot of NOX to cause smog. The extra noise does not hurt the CRD which is a heavy duty engine designed to take it. By injecting exhaust into the intake, it reduces the free air and excess oxygen and slightly quiets the engine. I am sure it will not bother you to have people state,"a Diesel EH!" , instead of, "is that a diesel?" .
Besides, you will improve your fuel economy and increase your power output.
Add the lift pump, you will be impressed.

Good luck and tell the tree huggers that pine bark beetles are high in protein :lol:

dtempler · **Posted:** Wed Jan 28, 2009 3:32 am

Your right, I don't mind the "a Diesel EH?"'s that I get with my MAF unplugged (and pine beetles are good protein). I was expecting that unplugging the MAF shouldn't really affect the the engine when cold because the EGR valve shouldn't start opening until the engine is warm. Is my thinking wrong here? It did seem like unplugging the MAF caused problems in the cold.

It sounds like I just have to solve my air in my fuel problem then I can get back to playing with my MAF so I can really see the difference without all the stalling and limping.

What sort of differences you are getting with the lift pump? Noticed any increase in fuel economy?

Keep the cold, and Canadian jokes rolling and thanks for the help.

nursecosmo · **Posted:** Wed Jan 28, 2009 3:58 am

because you have a confirmed air leak it will be worse when the temp is very cold. The colder the fuel gets the thicker it gets as well. When the fuel is like molassas, it is hard to get it to go through the filter, so there is a higher vacuum from the supply pump which sucks more air into the filter head. Unless you can repeat the rough running symptoms reliably with MAF plugged and unplugged at the same temp every morning it is likely just a coincidence. I would bet that if you add a lift pump and fix the air leak your problem will go away.

warp2diesel · **Posted:** Wed Jan 28, 2009 8:59 am

I kept bleeding out the air on a weakly basis before the lift pump and could not find the air leak. After I installed the lift pump it was like my engine, "Got its life back", and ran a lot better. Then I found the leak at the heater plug. Since I fought vacuum leaks for several years on the old truck I traded in for my CRD. My wife's TDI has a very small Vacuum leak that makes it crank an extra 4 to 5 seconds before it fires up and stumbles for another 10 seconds, it will get a lift pump as well.
To me, vacuum leaks are on the same level as terrorists and should be terminated.
Now you have an Idea Why I have so much passion on this topic. Sorry I do not agree with all of the Die Hard Stock owners, they can live with the potential problems if they choose to, I have chosen to not live with the problem.

Good luck, and tell the "Dead Tree Huggers that each ton of dead tree puts out 2.87 tons of CO2 as they rot" of course, "Building homes slows the process and reduces CO2 emissions" . I love to blow their pea brains :lol:

How do you know you are in Toronto?
You can see through a full cup of Tim Horton's coffee all the way to the bottom of the cup.

Weird sound, mad shaking and stalling?

Who is online