Engine runs fine but will not turn over 3000rpm no misfire it feels like it's hitting a governor limit or something I have replaced plugs, new fuel filter mostly because due,also tried new ign. coil on each cly. no change, replaced crank sensor as some had found to be culprit of same problem no change. I'm really scratching my head. I never had a CEL or no faults present I ran while monitoring with scanner and checked throttle percent appeared to be accurate. ?????? Any help appreciated!!

 

does the throttle body open up all the way? what is fuel pressure if the pump is weak then it may cause this. any new items added to the crank shaft ie pullies . hook up a scan gauge does it say the same as the tach?think exhaust,,, if the cat is clogged then air /exhaust cannot exit fast enough.. tak off the pipe loosen it and start the rig .. it will be loud if it revs up then the cat is clogged

 

Yes I've checked the throttle body, and I've thought of both the fuel pressure but have no way to check it and thought of the cat also. being disabled has made this a slow process for me as my funds are limited, I've been trying to save but it's tough in these times. I bought this truck brand new and this is the first problem I have ever had with it. Thanks for your input I really appreciate it. God Bless!

 

do you have a scan tool? if so without the truck running look at the TPS throttle position sensor. you should see a range from 20 to I think 80full throttle. I had a issue in the past that I wore out a spot in the TPS causing similar issues if you are in Houston area there is a guy that is good at fixing cars..

 

No I'm in Virginia and I just recently tried a new TPS as I had a friend suggest that might be it. To me it acts kinda like it's hitting a rev limiter. Thank you friend for your suggestions I'm gonna try and find someone to help me check the fuel psi and catalytic converter. God Bless!

 

On the off chance, not saying I have or know the answer...
Chasing down something awhile ago in my 3.4 (96 4Runner) I unplugged the knock sensors and ended up with a similar rpm limit.
I don't know the testing procedure for the harness and sensors, or if it could be done from the connector, given the location of the sensors.

 

I am surprised the ecu is not throwing a code.. fuel pressure is a must check also replace the filter . it is on the frame below the drivers seat.. check the fuel pressure regulator diaphragm make sure it holds a vacuum.

 

Thanks very much for your input and I'll check in to that as I've felt like all along that is was some kind of sensor problem, before become disabled I was a top technician for Cummins Diesel and experienced similar problems with some of the diesels when they had sensor or wiring problems. God Bless and thanks to all for input.

 

I replaced the fuel filter first thing and do regularly and I too am surprised no codes but I've seen it quite a few times before. I'm really not sure what's actually going on a friend who works at a garage nearby told me the other day their wrecker was doing the same thing and they found out that the alternator was causing when replaced it cleared up??????? I'm really mixed up getting so many different solutions...not that I don't appreciate the input! I will post the solution as soon as I find it.

 

some cars / trucks use the alternator as a tachometer