Infi30t

I have done searching through this forum and have found nothing describing what I have going on here...This is my Great grandma's I30t and something is wrong with it. I picked it up from her today and she was complaining that there is no power. She said when she puts her foot in it to go or get around someone, it doesn't do anything. So I took it and i put "my foot into it" as she was saying as im driving at about 40mph and she is correct. I can floor it and it just sits there and revs to about 4-4500k rpms. And it will barely move. Now I can feel it downshift before it does this so... After driving it for a bit it seems to happen at about 3/4 throttle and up. Other than that it shifts perfect (occasional hard shift here or there) and as long as its under 3/4 throttle its fine. But I don't want her to get into a bind and have to use a little more power than normal and not have it there for her. What this sounds like to me is some kind of sensor. Does this sound right? Drives fine normally, but any hard acceleration it gives out. What do you guys think this could be. I am fairly mechanically inclined so shoot away!
Thanks in advance!

Infi30t

So I took the car to a local transmission guy that is quite reputable and he said the transmission is doing its thing correctly. He said it is hitting the rev limiter. In park it does not hit the rev limiter, it revs all the way to red line. But when driving and I floor it, it will only rev up to 4500 and just hold there... Any ideas????

Mad_A

iTrader: (2)

If you are driving and you don't floor it, but instead steadily accelerate at perhaps 50% throttle, whatever is needed to keep from upshifting.. how high will it rev? will it reach close to the red line before up shifting, or still only rev up to 45k rpm ?

Infi30t

It will only rev to 4500. I had the PCM or ECU whichever it is diagnosed, and the shop I use says it is not that. They said it could be something int he wiring, but need it for a full day for testing, but i was hoping I could find out here, because I can't get the car from my great grandma for a full day for a little while.

Sasquatch

MAF Sensor?

christopher.spitler

MAF SENSOR!! I had this same problem... to the letter. Bought a new MAF from Nissan dealership (b/c it was cheaper than Infiniti) and it's like a new car... Also, don't let them sell you the MAF with the intake air RTD in there. That about a $400 part. You need the one that's about $100-150. I'll see if I can dig up the part number for you when I get home.

Infi30t

Do you think that's what it is? There is no codes or anything. I'm willing to try anything!

christopher.spitler

You know, if you were my neighbor, I'd put $50 bucks on it. Bad MAF input to ECU limits revs to 4k-4500k roughly. That's when I realized it was the MAF. Besides that, you get poor shifting. Sometimes when it's floored it never shifts from 3rd to OD or from 2nd to 3rd, right? Here's a good way to tell: Get some CRC MAF cleaner. Follow the directions on the can, and clean your MAF. The car should drive a little bit better. Then, go replace the MAF sensor. It's like a whole new car. Let us know how it turns out.

Infi30t

Well replaced the MAF sensor tonight and its perfect! But with one problem comes another... The MAP sensor is now shot... It runs great when I step on it, but when I come to a light or a stop, it dies.... Very upsetting as it was at least running before the fix... So I guess I will buy a MAP Sensor tomorrow and replace that as well. Does anyone have a picture of where it is? I heard its attached to the throttle body but where? I can't seem to find it...

Infi30t

So in the end all it ended up being was the MAF sensor. I was sold a universal by Advance Auto Parts that had an extra pin with it and that was screwing everything up. SO my repair shop had it for 3 days before we figured this out and thankfully that's all it was. I have unplugged the electric motor mounts and the car drives like brand new again. Got the correct MAF sensor in it and all is well. Never been better. Thanks for all the help. Thanks again to you too Chris!
P.S. Don't buy your parts from Advance Auto Parts, I have been told their parts are low quality and most are universal meaning they fit multiple cars even though they fit perfect on your car. Do research instead of settling for low quality and rushing like I did. I just wanted the car fixed. Never again...