I have noticed that my car is missing some power NA, mostly in third gear Doing runs with my friend shows that im about 2-3 cars difference. Im running a short ram with a K&N cone and fuel filter, injection cleaner, sea foam, TB clean and oil change have been done recently. The spark plugs have also been changed recently but they are one step colder NGK coppers and gapped to about .37 for nitrous. I dont think the power loss would be because of the plugs, I searched and people with colder plugs dont notice much of a difference. I have no engine codes or ghost codes and I am at 94k miles. I think that it is possible that the MAF might be going. When I had a Fidanza flywheel in, I was having that bogging after gear change issue may have been the MAF, changing the intake made the bog harder or lighter. This bog can be felts after going into 5th gear on my stock flywheel. Can my problem be caused from the MAF or will a dying MAF give me much more serious problems? The Throttle Position Sensor and knock sensor have also gone through my mind but I dont have money to just go replaced sensors. Anyone have any ideas. Thanks.

 

I would first check this and replace it with plugs within the OEM heat range, then try a knock sensor.

 

but wouldnt the ks throw a ghost code if it was bad?

 

Originally Posted by JeEvE
...The spark plugs have also been changed recently but they are one step colder NGK coppers and gapped to about .37 for nitrous...

"About" .37? I'd try it closer to .037-.041 or so (check the manual). And I'd use the correct heat range of NGK plugs, unless of course you really are running nitrous.
I'd also get rid of the short ram. (stock midpipe with resonator makes same, if not more power, as evidenced by a recent post on here comparing dyno results of stock to a Frankencar midpipe).

Are you running injector cleaner AND Seafoam in your gas? Why? A good quality 91 octane gas should be plenty by itsself. Injector cleaner or Seafoam will not make your car faster, unless your injectors are really that dirty. And even then, you only need one of them every few thousand miles or so. I also doubt you'd feel THAT big of a difference (you said 2-3 cars difference).

If you don't have any codes, I'd skip the sensors for now and check the basics.

Dave

 

Thanks for the reply Dave. I meant to say .037, sorry about that. They are all gapped to the same, either .037 or .038, I just dont remember. I am running a 50 shot so that is the reason for colder plugs. I decided to get a short ram with a midepipe so nitrous nozzle can go into the midepipe. I saw the thread about losing power from the midepipe so I will probably go back to my hacked airbox, I never liked extra noise from the short ram anyway.

I usually use 93 octane gas and run injection cleaner and seafoam through the intake (brake booster) every once in a while to just make sure everything is clean. Its just for maintenance and I do it around every 6k miles.

I think that the MAF is what the problem is. The bogging into gears seems like it is gettng worse. I can just buy one from Napa and see if it fixes the problem, if not then I can always return it. If thats not it then I will start looking into other things.

 

Glad we got a few little things cleared up (meaning you now sound like you know what you're talking about; I was a little confused about that with the wording in your first post). No offense meant.
My understanding about the MAF is that when it is bad, it will give a CEL and code. Being an electrical device, there are ways to test it. In my '97 FSM, it starts on page EC-104 and goes through EC-109. The first tests require you to get to the pins on the ECM. The easier one begins on EC-108. Here's a quick rundown of it (I can email scanned pages to you if needed).

Check Power Supply
1. Turn ignition switch off.
2. Disconnect MAF harness connector.
3. Turn ignition switch "on".
4. Check voltage between terminal "3" of harness connector and ground. (Looking at harness connector, it goes like this: [1 2 3]. On mine, terminal 3 on the wire harness is a red wire. Voltage should read battery voltage.

MAF sensor
1. Turn ignition switch "on".
2. Start engine and warm it up sufficiently.
3. With harness still connected to MAF sensor, check voltage between terminal "1" and ground. It looks like this [3 2 1]. Backprobe terminal 1 (a white wire).
Conditions Voltage V
Ignition "on", but engine stopped Less than 1.0
Idle (engine warmed up) 1.0-1.7
2500 rpm 1.5-2.1
Idle to about 4000 rpm* 1.0-1.7 to approx 4.0

* Check for linear voltage rise in response to increase to about 4000 rpm in engine speed.

4. If negative, remove MAF from air duct. Check hot film (very thin wire) for damage or dust.

If you use a K~N or other oiled filter, you might want to clean the hot film inside the MAF very gently with a spray electrical contact cleaner or clean it with a cotton swab and rubbing alcohol (VERY, VERY GENTLY). Some people have over-oiled their air filters, and the oil coats the hot film, making the MAF give bogus readings.

If the MAF passes the above tests, I would start looking elsewhere. There are tests for the back of the ECM, but I don't think that would be it unless you've been playing around with it. Odds are it would be something else.

Before you buy a MAF sensor from NAPA or wherever, ask them about their policy on returning electronics. A lot of places won't take them back, and you could get stuck with an expensive MAF that you may not need.

Hope this helps.

Dave