Hello. I'm new to this site. This is my first post. Sorry it is a long post,but it's been a long running issue. : 2002 DLX 2.4L std trans. I'm positive at least one of you here has the sme problem with your truck. *** Bogging down,power loss,rough idle,terrible mpg. I have replaced the following : injectors,coils,plugs,o2 sensor,A/F ratio sensor,both cats,coolant temp sensor,MAF sensor,TPS,cam and crank sensors,fuel pump,filter,fuel pressure reg.,idle control valve. Pressure test fuel system ( 40 psi ) smoke test,no vac leaks,no overheating,no fluid leaks,no smoke out of tailpipe. I've even replaced motor ( complete ) and it still has the above symptoms. Any ideas ? I'm thinking it may be electrical/ fuel issue. It does feel like its starving for fuel,and when I let go of acc pedal,it bogs down like it has a jake brake and makes a wooo sound. At my wits end ! I know this is a common Toyota problem,especially high mileage vehicles. I've search all over but no one seems to be able to pinpoint the problem. thx for any help *** all replacement parts are factory or Denso ***

 

I had something happen to me that I'm trying to figure out now too, I got stuck on the highway after I lost all power in my 4 runner. I went ahead and was turning on the highway starting losing power my battery light came on and then the car died. I went and got a new battery didn't fix the issue and now I am not knowing what to look for now. I was told it could be the relay fuse for the starter but not sure how to figure out if that is what it is.

 

Neither of you had the MIL trip ??

If the MIL has not tripped I would think long and hard about trying another ECM.

Any more I keep a spare just for testing!!!

To the OP have you done all this work or had it done?/

If your paying your putting a bunch of kids through collage !!!!

All these parts you replaced tested as bad ??Then they were replaced with new parts out of the box??

When the pump was changed what did the tank look like ??

Crushed or kinked fuel line .

 

I have not bought a new starter relay I was wondering if that could be a issue to cause what happened to me. But I did get a new battery and that didn't do anything but the lights come on just won't start for me.

 

Did you check the PCV valve?
Do you have oil in the intake hose between the air cleaner, and the throttle body?

 

It sounds like possibly an alternator issue. If it's driveable,you can try one of the larger auto parts chain stores. they should be able to test the alternator / starter systems for free. you need to find out the voltage the system is putting out. It should be 14.2 volts . If not,may be the alternator,since you've already installed a new battery. I hope this helps.

 

I have replaced the pcv valve. No oil between air filter housing and T/B either. Everyhing has been replaced / checked / re-checked. No vacuum leaks,etc. No codes / no check engine light. To me,it's an electrical issue,short to ground and it's affecting the throttle. But TPS checks ok. But it has to be electrical problem in T/B circuit. This is cable controlled throttle,not the drive by wire on 2003 and up models,which I know have the same symptoms.

 

I've done some of the work on it and mechanics have done some also. No kinked fuel lines,no obstructed lines,no vacuum leaks, . Fuel tank inside is crystal clear,not one speck of dirt. Four fuel filters in 5 years. New pressure regulator. Everything new. The issue is not mechanical. It is electrical affecting the TPS circuit. But the mechanics are stumped because no codes/no check engine light. I know my truck,I drive it for a living, and the problem is at TPS circuit. But since I drive / push / pull my truck during the week,I have not been able to leave it at an auto/electrical shop for an extended amount of time. I will bet my left shoe its TPS related. Hard to find a good mechanic that will tackle this problem. They are scared because no codes/cel . Over 65 mechanics have checked my truck since this problem started. Vast majority have ˟˟˟˟ for brains. This has been my experience. IT IS AN Electrical issue . common to Toyota vehicles.

 

I have the same problem and have found out that it's a short somewhere. Just can't find where! Try unplugging fuses and driving it to see if it runs better. If I pull the fuse for the dome lights it seems to run just fine but then I have a lot of electrical things not working. On my 96 4runner it's the dome light fuse, and I can't find any wiring schematics for it, and wiring is a foreign language to me.