Hi All,
I have an ’08 KDJ120R and as I was approaching 150,000 Kms I had read a bit about the D4D injector and fuel issues on here, Pradopoint and a few other sites. The engine was still running fine although I had noticed more of a clunk on cold start and that idle was not as smooth as it once was, also that annoying buzz around 2500 rpm under load. I bought the car 4 years ago with 50,000 on the clock and it has always been serviced on schedule (with Toyota). We tow a camper trailer periodically but overall the car has not had a hard life.
The consistent issue I turned up in reading about it was that water seems to be the No.1 killer in CRD engines (not confined to the D4D either). So having read into it a bit, I decided to get a Water Watch alarm fitted. Before fitting, the mechanic wanted to
check the injector
feedback which he did quickly and the news was not good. There is a technical term, but he used one starting with the letter F. So I took it to
Cooma Diesel in
Canberra and they kept the car overnight so they could do the full diagnostic
check. The results pretty much confirmed the initial analysis as follows (excuse the table spacing):
Cylinder Cold Start 10 Sec 30 Sec 2 Mins After
Test Drive
1 -2.7 -3.0 -3.2 -3.3 -3.3
2 1.2 1.2 1.2 1.5 1.7
3 -1.3 -1.3 -1.3 -1.6 -1.5
4 2.3 2.6 2.8 3.2 2.0
What is interesting is that apparently Toyota allows for a maximum of 3.0, although Denso (the injector manufacturer) recommends a maximum of 2.0. Either way it was not good. They also took fuel samples (pre and post filter) which showed clear evidence of algae and metal fragments.
Having always had the vehicle serviced with Toyota, it is disappointing that they had not picked this up (just had it for 150K service) as one or two of the injectors are outside their own stated tolerances, and this issue (if I can call it that) is not unknown with the D4D engine. However, Toyota servicing standards are a separate topic.
I had been toying with the idea of getting a new car, so a bit of a decision point I guess. It still runs fine, so sell it now or fork out a substantial sum to have it overhauled and hang onto it for a while to come. Alternatively, I could have asked Toyota to fit new injectors, which would buy some time but doesn’t address the root cause of the problem (likely water contamination). As with many of us, the car is set up exactly as I want it and when you add the costs of retro fitting all the bits and pieces on top of trade in price, I decided to get it fixed as I do like the car and at least it is a known quantity in all other respects.
So off it goes for the following:
Compression, leakage and valve clearance tests (all good fortunately)
Remove and clean both fuel tanks
Pipe cleaner
check all lines
Replace both fuel filters (news to me, there are two)
Replace fuel pump
Replace injectors
Replace rail assembly
Fit tank breather
Re-assemble and initialise pump, code injectors
Fit Water Watch alarm.
The cost was painful to say the least (enough to seriously consider the trade in). But having got it back now I am delighted with the way it runs. No knock on cold start (minus temps here at the moment), it settles down to a very smooth idle instantly on cold start and no discernible buzz in the 2500 rpm range. Hard to tell a power difference and haven’t had it back long enough to see if fuel economy is affected or not. But it does feel like a new car.
The interesting things I picked up from this, or things I didn’t know which may be of interest?
Of the two fuel tanks in the 120, the front one is plastic (good) and the rear is steel (not so good).
The rear tank has a drain plug, but the front one needs to be removed to drain/clean.
There is a second filter (10 micron) between the two tanks which (if they even know it exists) Toyota has never changed in six years of servicing.
The tank breather sits in the rear drive shaft
well just above the shaft. Lousy placement in terms of dust and water ingress.
Toyota will use 3.0 as max
feedback variance for the injectors, the manufacturer recommends 2.0 which is quite a difference.
Anyhow, will see how it goes from here, but thought that might be of some interest to D4D owners.
Cheers,
Matt.