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Hello! Good day lads, Eng is not my native language, sorry if i mess up a bit.
Audi 1.9 TDI 4-inline rotary pump fuel mixture
So car has rotary diesel DI pump driven by timing belt, there is limited ECU injection timing however. Car runs ideal, however only problem ir really hard starting and huge white smoke amount once it starts, that goes away and after a while there is no smoke whatsoever. Ideal idle, ideal exhaust etc. And starting trouble is after car sits for 10hours. So this fault is only first start in the morning.
Car has diesel fuel tank from different engine, it has low pressure pump, however this engine doesnt have such pump by default and has only one rotary pump. Injectors are new, compression tested by removing head and measuring + visual inspection of everything. Temp sensor wiring tested and sensor is new. Problems started after new injectors, right ECU was fitted, wiring corrected. It was done because emissions where bad. Starting problem appeared. There was idea that this intermittent problem is air leakage, but i fitted one way valves near filter and pump on both lines, did not help.
My theory goes like this: this additional pump causes overall pressure to be too high and cold start results in excessive fuel injected and a lot of cranking. In cold weather (minus -5 celsius) car starts ideal.
Is this plausible? I mean too much fuel. This engine is really primitive.
Last edit: 2 years 4 months ago by matrintrash. Reason: Typo and some additional info.
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