2001 MPV missing / stumbling under load

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

Hi all,

I know questions like this have been asked before, but mainly in regard to 2002-2006 MPVs. I'm confused as to exactly what to check and in which order.

I have a 2001 MPV with a 2.5l V6. It idles and revs perfectly in Park and Neutral, but will miss badly under load from about 1500 to 3500 RPM. Under hard acceleration, at RPMs above 3500, it seems to accelerate fine.
I replaced the Air Intake Manifold gasket as suggested by one of the TSBs, but the problem still exists. The dealer replaced the MAF sensor recently so I doubt that is the problem.

Any idea where I should start next on the trouble shooting list? When I had the Air Intake Manifold off, I noticed a LOT of carbon buildup and have since run a bottle of injector cleaner through the gas.

Help!
Joshua

subearu

Cleaning the carbon off the intake while you have it off is the best. Another possible source of a miss under load would be spark plugs / wires / coilpack.

-Brian

unclesam09 · Newbie Joined: 17 Apr 2010 Posts: 4

I had (what seems) to be a similar situation on my '04 MPV last year...and I tried a variety of things too....

It took 6 months for it to get bad enough for my CEL to turn on (so I could read the codes)...ended up being my #5 "coil"

I had the #5 replaced and all 6 Spark plugs (for about 600.00) OUCH!

Steps I wish I had taken....

>Wish I had bought a tool...There is a "tool" about 75.00 that you can use to check out the coils while they are on the car (I will try and find you a website)...I found it through a mechanic in Houston, TX.

>Wish > I would have bought all 6 coils myself (then used this site) to change myself....I would have changed All Coils and Plugs, Plug Wires, PCV valve and hose at one time....

My money is on a bad "coil"....

Best of Luck...I know it's a pain driving it when the MPV acts this way...Terrible design by Mazda / Ford.

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

unclesam09 · Newbie Joined: 17 Apr 2010 Posts: 4

I didn't realize they had different coil configurations? - I don't know if it would be your coil pack causing this issue?

Check out YouTube...about testing the coil, I found some great videos showing how to test it using your Ohm meter....Found the videos after I bought the "coil" pack for my Subaru (now I have 2 good coil packs)!

On my Subaru (completely different vehicles)...I changed coil pack, plugs and plug wires, fuel filter, MAF and cleaned the throttle body...still had intermittent issues.....finally replaced my Crank Sensor all is right with the world now.

Fyi...The guy in Houston's name is: Scotty Kilmer (google him) he has a web site and a youtube site....You can also send him an email (and he DOES respond) quickly.

Good luck.

Ken

12Ounce · MPVClub Addict Joined: 19 Aug 2007 Posts: 1745

We have a 2000. It also has the single ignition pack that contains the three coils ... fired double-ended. The odometer is somewhere around 250k miles. The coil pack is still original.

The only poor running issue we've ever had (other than no coolant leading to blown head gaskets) was started by poor/no attention given to air filter. This led to excess oil being sucked out of crankcase ... causing heavy carbon build-up in intake manifold arteries. Very poor performance once this happened.

After removing/cleaning intake manifold, installing new filter ... took this opportunity to replace plugs and spark cables ... all ran well!

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

12Ounce · MPVClub Addict Joined: 19 Aug 2007 Posts: 1745

I think I did not remove the cables .... just unbolted throttle body and laid aside. Not sure about your other question.

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

I got it all apart. Changed plugs and wires. I'm in the process of cleaning the intake manifold; it's heavily caked with carbon. What a drag. We'll see how it runs, if it runs, tomorrow.

j

12Ounce · MPVClub Addict Joined: 19 Aug 2007 Posts: 1745

I expect a marked improvement. Did you replace the air intake filter?

steve12955 · MPVClub Resident Joined: 23 Jan 2004 Posts: 664

Hello,

While you have it apart also check the air intake tube - the rubber accordian-like hose that runs between the air filter box and throttle body. After years and countless heat-cool cycles this hose can harden and split along the folds and cause intake leaks. It's about $30 from the dealer.

Good luck,

Steve

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

I have it all back together but it's still missing under load. It idles fine, but the more load I put on the engine, the more it misses.

I'm going to replace the coil next, unless anyone has other ideas. :/

j

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

I replaced the coil pack and that fixed it. No more missing and it runs super smooth. I now have a VERY clean engine with new spark plugs and wires. Wink

Odd, but the CEL just came on after about a half hour of driving. I'm going to pull the codes, but I can't imagine that it's anything serious. Is this is common symptom after a major tune up?

j

12Ounce · MPVClub Addict Joined: 19 Aug 2007 Posts: 1745

Wow! ... and congratulations. I would have never expected the coil to be the problem without CEL's! AND NOw the CEL shows up .... ??.

Perhaps loose hoses or other leaks??

jyoun3 · Newbie Joined: 18 Jun 2009 Posts: 14

Isn't that crazy? It was missing and sputtering like mad with no CEL. I finally get it running butter smooth and the CEL pops on. Annoying as heck.