1999 Tarago high fuel concuption and ECU conectivity

[crustie]

Hi Group First Post

I have had 2 Toyota Tarago's over the last 17 years first was a 1989 Tarago which some one bent by hitting me in the side so become a boomerang,

so next brought a 1999 Tarago 2.4 fuel injected in 2002 had 70000kms on the clock after 11years only has 200,000kms I only live 3 kms to work but the motor went bad (water in oil and oil in water) probably too many short runs so had a Japanese import put in for $3000 not quite sure which engine it came out of, was told the new engine had a crank angle sensor but not hooked up to my car think it was around 2006 model engine unconfirmed (I can get the serial number from the engine if it helps to Identify the engine) and It seems to have the original ECU still in it. The problem I am having is the high consumption of Fuel, normally out of a 60 ltr tank I would get 550kms aprox out of a tank around town , BUT since the new motor went in I get around 450kms to a tank, not sure why the van seems to run fine MAYBE a little down on power for a new engine but does run fine

Engine fitter doesn't want to know about it and too much time has now laps to go back

So I thought I would have a look at the ECU but have run into a problem I can only finds the one 22pin TIS port on the van which I brought the adaptor for to "MINI VCI FOR TOYOTA TIS OEM Techstream V7.31" off ebay which is OBD2 but fails to communicate to the ECU have I got the right unit? the software TIS settings are not helpful for Australian Toyota's but tried lots of options but no joy

so my 2 questions are

1. why the high fuel(gas) consumption ??

2. how to connect to the ECU with out paying $1000 ??

Many thanks

Crustie

p.s. by the way I was an Electrician and now after Elect. Engineering Adv. Dip. employed as Electrical Engineer So have a fair understanding of things with wires but I don't know everything and any help appreciated

[phongus]

Hmmm pretty sure newer generation (post-2000) engines didn't fit the first generation (1990-2000) of Taragos, however I could be wrong. If you could supply the engine model that would be good.

From my understanding, only 2 engines fit the first gen Taragos, that is the 2.4L 2TZ-FE (standard) and 2.4L 2TZ-FZE (supercharged)...the latter not sold in Australia, which was quite disappointing. If the engine was replaced with a standard 2TZ-FE then it should run as per normal, however if the timing is slightly out, it might cause minor issues. With my Ford, when the timing was a little to advanced, it would only run well on 98RON fuel, but horrible on 91RON (lost about 100km/tank). Have you tried running 98RON fuel to see if there is any difference?

Here is a list of items that may cause high fuel consumption:

Oxygen sensor: Tarago has 2...if they have never been replaced/inspected, I'd have a look at these first. They are one of the major sensors for fuel injection control...a failed one will send bad signals to the computer. Some more information if you are bored: http://www.buzzle.com/articles/signs-of-a-bad-oxygen-sensor.html

Vacuum leak: A vacuum leak can cause high fuel consumption, the larger the leak, the more work on the engine to produce the right amount of vacuum according to the ECU. It just puts another load on the engine that is not necessary. Usually after an engine transplant, a vacuum leak can be found at the inlet manifold...you can try checking by having the engine run (at operating temp) and spraying flamable aersol around the intake manifold, if the engine picks up revs there is a leak.

Block exhaust: A block exhaust, such as at the catalytic converter or muffler restricts exhaust flow. Engine loses power and you stomp your foot down more (even if just slightly) to move the same pace as you would with less pedal and breathing engine. Only way I can think of easily checking this is to hit the exhaust system lightly with a spanner or something and listen for any odd rattles, usually quite noticeable rattle.

Intake air filter: A severely blocked filter will restrict air flow to the engine. This again can reduce engine power and so you hit the accelerator harder to get more power out of, although I rarely have seen people have much fuel economy issues with a blocked filter, unless a cat/possum/mouse family live in it.

General maintenance: Inspect fluid levels and have a look at the spark plugs. See how the plugs look like and replace them if you can. Usually if I get a second hand engine and throw it in, I replace things such as spark plugs, leads and give injectors a dose of injector cleaner (through petrol tank). Then the obvious oil/fluids change. This will allow you to keep up to date with general history.

Now another option, although highly unlikely, they bought a 2TZ-FZE engine and put it into your car without the supercharger. Although the engines are quite identical, internally they are different. The 2TZ-FZE engine has a lower compression compared to standard (as to suit supercharger), pistons/rods were coated with something to make them stronger, piston oil squirters to cool pistons more effectively and some other little bits. If this engine was running with a standard ECU without a supercharger, it will not run as intended and will have lower power compared to the standard engine.

Hope that helps some what :)

Regards

Phong

[crustie]

Hi Thanks Phong,

many thanks for your detailed reply

at this stage I can only see one (1) Oxygen sensor after the cat converter but will have a good look Monday

did notice a leak on the header to exhaust joint before the cat converter just under the drivers door

so brought to ring gaskets to put on Monday not sure if it will help but needs doing

intake and exhaust look fine had new intake filter not that long ago and no power problems

I service the car every 10,000kms new oil filter etc. just been done

so its vacuum or oxygen sensor at this stage will investigate Monday

also where will I find the model number and serial number for the engine is it just under the seat ?will look for it Monday

they told me they replaced the spark plugs on engine change as I said before the car runs fine just loves to drink

many thanks Keiran

Had another play with the obd2 reader but still no joy any one have any ideas

[phongus]

No problem Keiran.

There should be an oxygen sensor before and after the catalytic converter according to the manual I just bought. I am not sure of their exact location though sorry, the picture is rather odd to read.

The engine number according to the manual and some images on google say it is located under the intake manifold...which unfortunately might be hard to see seeing as the engine is mounted slanted.

It seems 1991-1993 had no crank sensor, while engines after 1993 had crank sensors.

Sorry can't help you on the OBD2 stuff. Don't know much on the electronics side of things!

[(mr2)]

Have you checked for power at the OBD plug, this might have been cut and used for something else.