[Sinned420]

So recently, my car started having these random hesitations under load. It comes and goes. Sometimes it'll be fine for a few days and then the problem will come back. There is a lack of power, accelerating from low speeds or from a stop, but once the RPM is above 2.5k the power all of the sudden comes back and everything seems normal. But if I slow down and accelerate again, the first few seconds I would have a lack of power and I can feel it shaking as if misfiring? I'm not sure what's causing this, I'm at work now but will look for problems as soon as I get home.

Any ideas? The wiring harness is new since 2 years ago. Changed spark plugs and distributor cap/rotors about 1.5 years ago. MAF is a re-manufactured unit from AutohausAZ from about 2.5 years ago. One thing I think it may be is that the car had been sitting for several days, but I'm not sure if it is the case everytime it happens.

 

[mrtalkradio]

Sure sounds like a MAF symptom, but could be anything really.
I would take off the caps and inspect, the rotors as well. 1.5 years, is well, 1.5 years.

 

[Sinned420]

Seems like MAF symptoms to me too, but I don't think the unit would be bad already... I might give it a cleaning just to see. Definitely going to check the Dist caps and rotor later. I hope it threw some codes to give me something to go on. I am hoping its not the throttle body wiring

 

[Sinned420]

Okay I checked the dist cap and rotors. It was really fouled up, lots of black build up on each contact point. I wiped off the buildup as much as I could. I'm not saying this is the issue to my problem but I definitely need new parts. I was also wondering, what about ignition coils? I've never changed those. As far as I know it's the original lol. I drove 60k miles since I've owned this car. The Dist cap and rotor has maybe 30k miles on them, does that seem right for them to need changing?

 

[mb rider]

I once had a similar issue with my SL600 and found it to be a bad ignition coil.This was causing a weak spark to one cylinder at low idle.You probably have two coils feeding each cylinder bank in your engine set up.See if you can get a way to test them based on your engine configuration.In my case I had 12 individual coils 1/cylinder, I used a stethoscope
To listen to each one and also pulled each one with engine running briefly to see how the engine idled.A bad coil will show almost no change to engine sound/roughness.Hope this helps.Good luck!

 

[mrtalkradio]

The coils are easy to get at. You can use an OHM meter to find out if they are ok. I used the search within the forum to find the values when I did mine, I have forgotten what is was though...9? I can't remember. If you take the rotors out, be sure to torque them properly, you can over tighten them in a heartbeat.

 

[Sinned420]

So parts are still on the way (caps and rotors). I really don't think those are the cause of the issue though, due to the nature of symptoms. I went ahead and unplugged the MAF and the car runs smooth now. It got bad to the point where driving my car up the driveway into the garage was a chore...once unplugged it drove better and the power was back. Of course it's running on default air flow settings which may or may not be the correct values at any given time. Well for temp testing purposes it showed that the MAF was the culprit. Not sure if I should order another OE rebuilt unit or just get a brand new unit from the dealership...I don't want to replace it again in another 3 years. (I checked the order history and the unit was ordered on 3/24/10)

 

[zsm722]

I'm having the same trouble. It's interesting because if you drive it everyday it will be fine. But sitting for more than 3-4 days and it will act up. If you jab the gas it will almost die. Also I replaced my remanufactured MAF almost the same exact time as you too. These cars eat MAF for breakfast it looks like. I should check my caps and rotors too. Looking forward to an update from you.

-Z

 

[nowhereman]

The coils are easy to get at. You can use an OHM meter to find out if they are ok. I used the search within the forum to find the values when I did mine, I have forgotten what is was though...9? I can't remember. If you take the rotors out, be sure to torque them properly, you can over tighten them in a heartbeat.

Bad readings from an OHM meter will show a bad coil, but good readings don't prove it's good. If the insulation between the windings has cracked it may pass the test but still short out when the high voltages are applied. Special equipment is needed to properly test coils, it emulates the engine.

If the coils are original it's probably wise to plan a replacement soon even if they turn out not to be the culprit in this case.