1HZ Poor fuel economy

[just cruizin']

My 100 series has always got reasonable economy, about 600 - 700 from the main tank. Now it's dropped to only getting 400 very rapidly, I'm assuming it's injector related but would appreciate other suggestions.

Thus what's the best method to fix and how should be flushed/ cleaned / overhauled. Are there fuel additives worth using to clean the fuel system.

[oldmate]

Have you checked for leaks?

[just cruizin']

Would be a big leak.

Nothing that obvious that would lead to that amount being used.

[samdumbert]

Did the change in fuel economy happen suddenly? Is it blowing black smoke?

[just cruizin']

It's hard to tell as the vehicle doesn't normally do that many km's but I'd say yes, and it does blow more smoke then usual, I put that down to the overfuelling ie bad economy.

[poppywhite]

Short runs arnt good for that motor they dont warm up much but depends on what you definiton of short run is.

Fill up with fresh diesel and use one of the injector clean additives chemtec/ nulon and go for few hundred k run.
Check for leaks along entire fuel system and check filter for tight. dont have to be big leak constant small adds up.

Let us know how you go

[hulsty]

A good cheap start, change all your filters, check the intake/exhaust for a restriction.

[Frankenyota]

How many km's? It's not uncommon for a 100 series 1HZ to need injectors doing at 100K.
Give it a service and change all filters as said.

Matt

[just cruizin']

New injectors And filters have been fitted fuel system I will double check tonight. I'll throw some fuel system cleaner through it. Has anyone used the CEM stuff before

[cruise75]

Had similar problem with my hzj75. Changed the filter and used a bottle of wynns diesel conditioner in a full tank of fuel straight after. Fuel ecconomy picked up considerably. If you use the additive every 2nd tank it will benifit the injectors as well as your fuel pump. You can use it in every tank of fuel if you think their may be a blockage in an injector. It wont hurt the motor.
Kenny

[colinwhirlpool]

Sounds like time for a valve adjustment and injector pump service.

Valve adjustment is very important on these engines.

[idh959]

Hi Guys,

Whats the average cost of vavle adjustment on these. My mechanic is looking at the valave clearance, and decided some shims need to be replaced, at about $400 incl labour.

Cheers,
Ian