Help! My car won't rev past 3,000 RPM!

57trimMKIII

Texas Supras' Slowest
Jul 14, 2010
133
0
0
DFW, TX
I've had an odd day with the Supra. Went for a short cruise with another Supra owner today, decided I'd do a small pull on the way to lunch. I noticed the car didn't rev as high as it normally did, even half throttle. So I made another short pull, this time with my foot to the floor, and the car seemed to be "stuck" at 3,000 RPM. I pulled over and told him something was wrong, he (being behind me during the pull) said he saw a small puff of blue smoke but I'm not sure if that's related. I then noticed the car was down to 1/4 tank and figured I may have gotten some bad gas. So I filled the car up, did a pull on my way back home, and the car ran like a champ! Pull strong all the way to 5,500 RPM. I shrugged it off thinking I had found the issue.

20 minutes later I had to get to work, so I putted over there. The car ran just fine (about a 15 minute commute), then as I turned onto the access road to get to work the car started acting up again. I then became frustrated because the problem obviously wasn't the fuel! Called a friend who is a 7M guru, and he told me his car did that once when he seized up his turbo. Relayed this to my brother, who said that seems possible because it seems like the car is being choked. However, I'm skeptical about this one because the car will build to 11 lbs. with no issues what so ever. So I texted another friend who is pretty knowledgeable about MKIII's, he said his CPS caused his car to do something similar. So now I'm thinking this is something electrical...

I've searched the forums and I've come up with several different answers:

Boost leak, bad AFM, bad AFM wiring, bad TPS, bad CPS, and so on...


Cliffs: No codes, no breaking up, it just won't rev past 3,000 RPM! :runaway:
 

Numba1Stuna

New Member
Apr 18, 2012
361
0
0
39
Nampa, ID
You did jump te1 and e1 when looking for an engine code right? Won't show up unless you do. Sounds like possible MAFS issue to me. Had the same problem. You don't have a K&N do you?

Sent from my LG-P999 using Tapatalk 2
 

57trimMKIII

Texas Supras' Slowest
Jul 14, 2010
133
0
0
DFW, TX
ryannelson91;1909684 said:
check the maf, tps, and cps for resistance

Have the day off tomorrow so I'm going to check all of these, along with checking for any codes.

My CPS started leaking oil a couple weeks ago, friend of mine thinks oil might have gotten on the contacts.

Numba1Stuna;1909696 said:
You did jump te1 and e1 when looking for an engine code right? Won't show up unless you do.

Sounds like possible MAFS issue to me. Had the same problem. You don't have a K&N do you?

No, what I meant by no codes is the car is not throwing a check engine light - sorry guys!

MAF, CPS, TPS, I've even heard fuel blockage! And no, I have a Apex'i intake on my car.
 

57trimMKIII

Texas Supras' Slowest
Jul 14, 2010
133
0
0
DFW, TX
Update!

Checked for codes today and got the following results:

Code 21: 02 sensor (self explanatory)
Code 31: air flow meter
Code 34: turbocharger pressure (fuel cut)
Code 41: throttle position sensor

Looks like the AFM, and/or the TPS is the culprit :nono:
 

57trimMKIII

Texas Supras' Slowest
Jul 14, 2010
133
0
0
DFW, TX
Reset the ECU and drove the car around the block, checked for codes when I got home.

Now I'm only getting one code, 41 (TPS), the other codes must have been stored codes.

Odd part is, the car idles perfect. I was told the car would be "searching" with a bad TPS.
 

57trimMKIII

Texas Supras' Slowest
Jul 14, 2010
133
0
0
DFW, TX
Unplugged the TPS and went for another drive around the block.

The car ran great again, looks like the TPS may be the issue here.
 

supraguy@aol

Well-Known Member
Dec 30, 2005
4,235
37
48
Atlanta
He's saying it's not the tps.

Clear answers never come from J.J.
They always require the recipient to do some thinking.