J30 runs great when cold but seems a little sluggish when warm

[Augy]

My '94 J30 runs great and is very responsive at the low end when it's cold. Once it's warmed up though, it seems kind of sluggish up to about 30 or 40 mph. I've seen posts on the MAF that indicate maybe that might be the problem. Does this seem logical? Where, exactly, is the MAF? I see a device just behind the air filter that has an electrical connection...is that it?

Thanks.

[drape123]

Yes, thats your MAF the thing right behind the air filter. disconnect it and clean it

[timinfini]

it seems like you knock sensor is bad. does it feel like your car have hikups and it jerks sometimes.

[chiller]

question, sorry for the stupidity, but how exactl do you clean an MAF?

[yodawill2000]

Spray it liberally with "ZERO RESIDUE" contact cleaner.when you take the hose clamp off and look into the MAF you will see a thin wire in the middle with a sensor in the middle. Thats what you want to clean.

And there is no stupid question We all learn from asking here .Helluva resource it iz

[gr8scott72]

Cleaning the MAF won't hurt but it won't fix your problem. It's your knock sensor like mentioned above. The stock knock sensor is a pain to get to also. I recommend getting a new one and a new wiring harness and relocating the new one to somewhere easier to get to like on the back of the intake manifold.

Knock sensors can be had from ebay brand new for $60 and I got the harness straight from the local infiniti dealership for about $15.

You can look around for a how-to to replace it. I had the link saved but not on this computer. I'll see if it's on my other computer at home. It's an article from a 300Z site.

[gr8scott72]

it seems like you knock sensor is bad. does it feel like your car have hikups and it jerks sometimes.

Oh, and you can have a bad knock sensor and not get hickups or jerks, just lack of power once it warms up.

[yodawill2000]

not sure where you live but I had a simular symptom and it was the knock sensors doing their job.Turned out a LOT of crap was lodged between the radiator and the condensor. Cleaned it out and problem was solved.Keep in mind Im in Texas and it happened when it was about 105 out.

[gr8scott72]

not sure where you live but I had a simular symptom and it was the knock sensors doing their job.Turned out a LOT of crap was lodged between the radiator and the condensor. Cleaned it out and problem was solved.Keep in mind Im in Texas and it happened when it was about 105 out.

Yeah, I remember when you posted that. I went straight outside and looked hoping it would be something simple like that for me but no such luck.

[gr8scott72]

Here's the link:http://www.angelfire.com/geek/....html