6.9 cold start issue

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QLD6point9

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Hey there guys and girls,

Just hoping for perhaps an easy answer here as opposed to diving back into the Bosch Kjet diagnosis manual (having been through the process before).

Story is, 6.9 that I own has all of a sudden (after previously working perfectly) presented with an issue whereby cold starts are not possible (cranks but doesn't start) unless you disconnect the fuel pump safety switch (blue plug on the fuel distributor housing) - see photo attached. (note: as described, if I do disconnect the blue fuel pump safety plug, the vehicles fuel pump will audibly be heard pumping fuel and the vehicle will start normally).

Recently, all k jet components had been refurbished by a Kjet specialist (auxiliary air valve, fuel distributor and Warm up regulator). New injectors have been installed, new fuel pump and new filter in the tank and also new inline filter.

I've got an exhaust probe that measures AFR (air fuel ratio) and I had previously tuned the fuel system to achieve almost perfect AFR results and had no issues with the vehicle for quite a good while (started first time every time).

The only items that haven't been replaced are the cold start injector and the accumulator.

I am wondering if this sounds like accumulator type troubles. Either way, it sounds like I am going to have to hookup the pressure test gauge and do some tests from the Bosch diagnosis manual.

I did however want to check firstly if anyone else has experienced this cold start issue, and whether it was for instance an accumulator issue.

It seems almost like a tired accumulator has decided to give up the game after perhaps 45+ years.... And or, I may have more debris blocking optimal fuel pressure delivery which I may need to also tend to (despite having previously replaced and cleaned all filters and gauze filters - including in tank filter).

Any and all suggestions welcome

Cheers James
 

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