Discussion in 'T3 & T4 Tech Help Clinic' started by Michael@92, Dec 27, 2017.
You own Kombi/s AND can still afford to eat?
I agree....but have a thought. If the thermotime switch is faulty...as in goes back to ‘cold’ setting everytime the current is cut to it instead of not firing up the csv when hot starting.....this would cause slight flooding and then black smoke on hot start.....I think....maybe lol
Yes, that's food for thought but how? The TTS operates via an electrically heated bi-metallic strip that grounds out the 5th injector - max 11 seconds inject time and the test posted above will confirm condition. Now I believe the TTS actually reads ambient air temperature via its own probe (just like the T1 in he ECU intake), not via the T2 or ECU so if the probe is supposed to read ambient air temperatures from minus something up to 68F when it opens the circuit to the 5th injector, then possibly, just possibly the probe could be shot and constantly reads below 68F. Don't have any guides to trouble shoot this possibility so perhaps pull the TTS, clean the probe, immerse in ice water and test resistance then repeat with 68F or higher. The TTS can be removed without dismantling the plenum and stuff by removing vacuum and fuel lines, electrical connection and use a socket. Tight but doable. Busdepot.com have new OEM VDO units at $99USD plus freight.
The ‘how’ part....who knows lol there just doesn’t seem to be another ‘logical’ explanation. Having said that, after spending a bit of time around 30+yr old l-jet, I’m sure we all learn that logic has to be forgotten sometimes haha
From my understanding the tts is a standalone unit as you said so possibly it is the ambient temp probe but of it which is stuffed.
Will be interested to see the outcome of this one! Always good to expand knowledge just hope that that knowledge isn’t too painful to get for the owner
The moment of truth!
Fed Ex have delivered a sufficiently low tech looking sensor. What could possibly go wrong. Fingers crossed for a simple solution.
I guess thinking simply replacing the air temp sensor would solve the hot start problem was hopeful – and indeed that has proven to be the case. Good news is I doubt I will ever have to replace that unit again! Thank goodness for ratchet spanners.
This leads back to the Thermo Time Switch as being the issue. Next week I should get a chance to test out the Cold Start Valve – to see if it is receiving the 11 second burst of power on start – and to try to a hot start with the CSV disconnected.
Can anyone recall off hand if you simply disconnect the black electrical plug going into the blue cold start valve connector or does the blue connector itself come apart?
Thanks for all the great help.
Oh well, guess thats one gremlin less to worry about into he future. Sorry I can't confirm the CSV injector connection as my EFI doesn't run that stuff anymore. But from memory, the CSV cap should be the same as the other 4 injectors where the thin wire slip on clamp thingie secures the cap to the injector. Slip the clip up and lift the cap away. Then you can do the test lamp test connecting the test lamp across both terminals, disarm the coil and crank for 11 seconds. Should be able to do this simple test cold and hot without having to remove the TTS.
By the way is the Temp2 Chinese?
International Auto and Motorcycle Parts Industrial Zone,Tangxia,Rui'an City,Wenzhou,Zhejiang,China
Thought as much with the clip assembly – thanks for checking and letting me know just to be sure.
Managed to spend a little time on it over the last day or so. It would appear the Thermo Time Switch is looking increasingly guilty. Disconnecting the Cold Start Valve seems to eliminate the problem. Starts hot or cold perfectly now – albeit with limited testing. Not quite ready to claim victory just yet – will still perform the electrical tests on the CSV plug to be sure.
Seems in our rather temperate east coast climate the CSV is rarely needed. Will order and replace the TTS in any case. Cheap insurance in my mind.
As for the replacement T2 temp sensor I installed – it has absolutely no markings on it all – in Chinese or any other language – (no discernible MSG or Soy Sauce smell either!) – so I’m not sure where it was manufactured. Might ask the good people at Bus Depot.
Many thanks for all your help everyone.
There shouldn’t be any issue leaving the csv disconnected as long as it’s secured to avoid any possible issues. Maybe wrap in insulating tape to seal and zip tie it to something
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