Plante11

First I want to say this WAS posted in the new users thread so I want to apologize before hand and I want to thank DennisMik for the response




Alright, so for approximately 3 years now I have owned my current Max, not my first but 3rd, and I have been trying to diagnose and solve the same problem for 3 years now. It is sort of an on and off thing, I am not continuously throwing parts at the car, but finally said enough is enough I need to talk to some people that really knows about these cars.

In 2008 I bought the car with 90,000 miles on it, Salvage title it had previously been totaled, front and back. When I test drove the car i noticed a hesitation around 2500-3000 RPM at highway speeds, and when I really get on the car around 3500-4000 its starts to stutter and loose power until 5000 then takes off.

First I thought it was a bad plug or coil, so I changed all my plugs to NGK plugs (previous owner used Bosch, and I hate Bosch in these cars). Then I unplugged all the coils one by one to see if I had a bad coil and everything seemed fine.

After the tune up and plug change it seemed to go away (maybe it was in my head) but it came back, this time it seemed like the hesitation and stutter points had changed, It was no longer a nuisance I hardly noticed it.

Then my starter went and i changed my starter, and for 3 months everything was fine until i thought my starter went again. Changed it out again and this time when i turned the car over all i got was a grinding sound almost like when you try to start your already started car. I though it was because of a bad connection, changed out my negative terminal (it was corroded) and it fired right up.

Every so often my starter does the same thing for a crank or 2 then fires right up (this is why i think its a bent flywheel) so I took my starter out and inspected my flywheel, and it looks fine no bent or damaged teeth



My next step was to look at my crankshaft sensors, I changed both crank sensors (by the oil pan, and on the bell housing). The connector on the bell housing had some dirt in it so i thought for sure the connector was the issue but it wasn't. I cleaned it and changed the sensor (I forgot to unplug the battery while doing this).

After changing the sensor on the trans the issue is worse so that is why I narrowed it down to these to things. The stutter is worse and i feel it all the time in every gear around 2500-3000, and the hesitation around 3500-4000 is back in 3rd-5th gear.
*Im throwing no codes by the way (i knew that was gonna be one of the first questions*


*What I have done*
-changed the crank sensors
-changed the spark plugs
-checked the coils
-checked the fuel pump (thought it could have been a fuel issue)
-ran 91 octane for a few months
-checked the flywheel
-cleaned my MAF sensor (using MAF sensor cleaner)
-tune-ups and oil every 3000 miles


**Help**
-could it be something as simple as disconnecting my battery to reset the new sensor
-did I ruin the new sensor by not disconnecting the battery
-could the flywheel be bent just not visibly
-any other ideas
-could it be fuel injectors

It almost feels like the car is lacking fuel during the sputter but my RPMs stay steady and speed are not effected while the car is sputtering


Thanks for everyone's threads by the way I am on the website all the time whenever I have an issue to help resolve them. Its like my troubleshooting bible.


Edit: Today I'm going to be cleaning all my battery terminals and checking the wiring to cylinders 2 and 4. Any other ideas?

njmaxseltd

iTrader: (19)

Check the MAF sensor signal.
Verify the TPS signal is clean.
Check the stalk on the coil packs. Remove them from the coil, take out the spring and look for corrosion where the spring sits on the coil terminal.
It sounds like you've got a misfire under load, which usually points to a weak spark.

036mtmax

iTrader: (11)

While your at it you should run a couple of ground wires if you haven't yet. One from neg to starter bolt and another from neg to bellhousing bolt. It's worth a shot