Advice needed,
My otherwise lovely 89 townace super extra 4WD 2.0L petrol (EFI) has been developing a very intense smell of unburned (?) petrol (or so, I think). The stink comes out of the exhaust pipe (I’ve seen no leak anywhere in engine or conduits), as soon as the van is started, and does not go away, even after a long run (engine hot). It can be smelled inside or outside, indeed, this weekend some guy asked me whether my car was running on some sort of gas (sure he meant cooking gas or methanol or whatever). Also, the petrol consumption has increased from about 10-11 liters per 100Km to over 13-15L p 100k. I have noticed this about 3-4 months now, and it’s getting worse by the day.
I have seen a mechanic, and he suggested the following:
a) Change spark plugs-never had a mis/bad/ or back firing, anyway, replaced (the newly fitted NGK) with bosch 4 point platinum, to no avail.
b) On regular servicing (oils, filters, rad flush etc) added in petrol tank injector cleaner and petrol treatment (both chemicals from Wynns), also to no avail. Any chance I may have added the wrong stuff?
Last recommendation was to change the rear exhaust box (which is a stainless steel from a VW Caravelle bus) and go see an EFI specialist for proper tuning. Any word on this? Anything else that may need to be looked at? Does anybody know what is the wire (oxygen sensor?) in the center exhaust box? How critical is it to have it/or not (if damaged)
Since I will be going to South Africa to get the above done, I would really appreciate any tip, suggestion or word of knowledge or caution.
Thanks in advance, this site is the closest thing to heaven.
Manecas
- (#7971) Manecas, 9 Apr 03 9:29
i'd go straight for the lambda (oxygen) sensor- it should be in the downpipe near the exhaust manifold and have between one and four wires connected. one of the wires is the output (the others if fitted are ground and heater supply) and if you put a meter on it when the engine is warmed up, you should see the voltage swing back and forth around 0.7volts. this should happen maybe twice a second. if it is slower than that or doesn't change, i'd replace the sensor. another area to look at might be a leaking cold start injector if fitted.
hth
- (#7972) david miller, 9 Apr 03 10:50
David,
Many thanks for the prompt and detailed reply. I will give a look at the oxygen sensor, which I am positive to identify. Could you kindly share some hints on how to identify a cold start injector and how to spot whether it's leaking? BTW engine is 3Y-E and looks and feels like new (as far as the eye can see)
Again, thanks for the answer, which I am sure will help the efi garage, if (when) I end up there.
Manecas
- (#7973) Manecas, 10 Apr 03 2:58
If your car does indeed have a cold start injector (later toyota efi systems don't) then, it'll be on the inlet manifold with a wiring connector and a fuel pipe going to it. Ian and Jim Adgo can help better here, having the requisite manuals, but basically you remove it, connect (only) the fuel line to it again, and turn on the ignition. no fuel should come out.
- (#8048) david miller, 10 Apr 03 13:53
Manecas
If I get time this weekend I'll scan the EFI section from the 3Y engine manual and send it you. It's pretty comprehensive with specs and diagrams and would be easier than trying to describe the components etc here in narrative. Could you please ensure you have a couple of meg free in your inbox to receive it.
Ian
- (#8049) Ian Dunse, 11 Apr 03 1:17
Just before you go tanking off to South Africa, it might be worth checking the engine earth strap.
If this is in poor condition, or not grounding properly, it could cause spurious signals that may interfere with the EFI unit. One known cause is to allow the injectors to inject fuel whilst the ignition is on, but without the engine actually running.
Good luck
dave Bright
- (#8050) dave Bright, 11 Apr 03 5:19
David, Ian and Dave,
Thanks, a zillion, for the extra tips and for the offer to send me a scanned section of the 3Y-E manual (Ian, yes my inbox can take quite a few meg).
I guess my weekend is now booked for a good cause. Will let everyone know of any findings.
Thanks,
Manecas
- (#8051) Manecas, 11 Apr 03 12:42