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Discussion Starter #1
While my truck was in the dyno shop getting a closed loop to open loop tune I got a disturbing call from the tuner. He said that he had the closed loop dialed in, but at about 4000 rpm we were loosing fuel delivery, the AFRs started to climb from 11.0:1 to 12:1 to 13:1 which is were he stoped loading the motor to avoid running it too lean. our next step was to see where we were loosing pressure so we hooked up a fuel pressure gauge to the front of the fuel rail. The gauge showed a pressure drop from 40psi to 20psi @4000rpm. All of the injectors were monitered and were working fine which leaves the fuel pump and fuel filter. The pump is a walbro 190 LPH with about 4,000 miles on it and toyota says their filters are lifetime filters which is more than likely bullshit, but the filter has about 41,000 miles on it. Has anyone had to change out their filter on a newer taco yet? I talked to gadget on the phone, but without being around the shop there are too many factors to diagnose a problem. He did sugest that the dyno itself (a mustang 1750, not inertial) might be the cause of bad AFR readings.

As always, Thanks in advance for the imput-Mike
 

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There is no way in hell those fuel filters are lifetime, especially with as much bad/dirty gas as we get these days. I would change mine everytime I noticed my gas mileage getting worse and it always helped with that. Those things are not all that expensive and only take about 20 minutes to replace, so I would start with that since if the fuel pump is pumping up to 40psi, I don't see why it would slack off.
Good luck!
 

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Discussion Starter #3
Yeah my thoughts exactly. A filter flow test/replace was my next step.
 

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Discussion Starter #5
Do you use anything special like a line wrench or just your standard wrench? I pick up my filter from the yota dealer today so we will see what happens.

Also I did realize that my mileage was shit on my last road trip so Iam think'n this will be my easy fix.
 

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Standard open ended wrench works just fine. I changed mine over @ 30K also. Hope that solves the problem. Good Luck.
 

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Make sure you replace it with a real Denso fuel filter from the Toyota dealer. I have seen serious flow restrictions from other aftermarket brands.
 

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Discussion Starter #8
I replaced it yesterday with a factory filter from the dealership. Truck seems to do great above 4000 rpm (no detination atleast), but how can I know for sure my truck is getting the fuel it needs without a AFR meter? The guy at the dyno shop sugested I hook a lap top up to the FTC and put a large number in the open loop fuel trims, to richen it up and look for black smoke upon acceleration, to show that the truck is getting more than enough fuel.

That method along with putting my truck back in the dyno shop are my last resorts to find out for sure if my truck is getting the proper fuel and a good open loop tune. Any suggestions would be appericeated.
 

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There are so many people out there with URD fuel kits you should be able to find someone with a wideband and knows how to tune our kits. Ask for someone near you for help. You can also check on some of the other Toyota truck forums.
 

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tacocharger04 said:
I replaced it yesterday with a factory filter from the dealership. Truck seems to do great above 4000 rpm (no detination atleast), but how can I know for sure my truck is getting the fuel it needs without a AFR meter? The guy at the dyno shop sugested I hook a lap top up to the FTC and put a large number in the open loop fuel trims, to richen it up and look for black smoke upon acceleration, to show that the truck is getting more than enough fuel.

That method along with putting my truck back in the dyno shop are my last resorts to find out for sure if my truck is getting the proper fuel and a good open loop tune. Any suggestions would be appericeated.
Theres honestly no point in doing whatever it is that the dyno shop guys telling you to do. Which doesnt make sense anyway. How the hell is the dyno shop tuning your truck if they arent hooking a laptop up to the FTC themselves? That black smoke thing is the dumbest advice ever, you never hear about someone having there truck tuned where the shop does it right.
All you need is your own wideband A/F gauge, which you can pick up for 250$ and a laptop to hook up to the FTC, if you dont have a laptop buy an old one on ebay for 50$. Then you wont need any dyno shop you can tune yourself. Its so simple once you really get it, anyone whos not mentally retarded can learn it, it just takes some time. Then youll be happy with your tune and youll have learned how to tune a fuel inj. vehicle.
 

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tacocharger04 said:
Do you use anything special like a line wrench or just your standard wrench? I pick up my filter from the yota dealer today so we will see what happens.

Also I did realize that my mileage was shit on my last road trip so Iam think'n this will be my easy fix.
Id get flare nut wrenches which are meant for it. Its not hard to kink the line.
 

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Discussion Starter #12
No, the dyno shop for sure hooked a laptop up to the FTC and did a really good job of tuning the closed loop. The truck runs great, the strongest its ever run with exelent driveabillty. This shop, in particular knew what they were doing. The black smoke technique was a cheep way for me to see for myself that I was getting sufficent fuel above 4000 RPM without a $100 per hour shop rate again or a $250 wideband unit. I will more than likely just drop the $250, when I get it, and take care of the situation myself since I have posted for local help and have not had any replies. Its cool though its just $$$money, money, money and then when you think you'r done, more money$$$

Thats the name of the game. :)
 
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