V8 Diesel Slow Starting

[JST]

Hi all,

I bought my 4.5 diesel 200 series with a slow starting issue which hasn’t improved with use (car had done very few miles in recent years before my ownership).

Symptoms are:
1. Cranks for a little longer than expected when re-started immediately following shut-down
2. When left 8-24 hours, cranking time ranges from 3-10 seconds!
3. Slight ticking at idle, possibly from an injector
4. Black smoke under acceleration (not extreme but visible in the mirror in some cases)
5. Fuel pressure seems to drop to 50psi almost immediately following shut down and slowly builds up to 4000psi when cranking


Its pretty obvious that there is a leak-back issue in the fuel system and it’s quite possible that some of the symptoms are related to secondary issues.

Warm starting doesn’t make it any worse.

I’d like to do a leak-off test on the injectors but this doesn’t appear to be possible, with the return pipes presumably under the cam covers.

Power delivery and fuel economy are both as expected.

Anything I can do to pin-point a faulty component? My guess is the SCV is responsible for the long cranking (allowing fuel to drain further back to the tank as time passes) and I could also be due an injector or eight!

Many thanks in advance - hopefully there is a knowledgeable Aussie on here!

 

[Workhorse]

Hi @JST, do you have a scan tool to read the injector values when the engine is both cold and then at operating temperature? Factory spec gives +/- 3 on them and outside of that they are out of spec and could have issues. If you haven't checked, do this first. Also, what year is your 200 and how many miles or KMs?

There is a pretty good FB group too: Log into Facebook - https://www.facebook.com/groups/200seriesowners

 

[JST]

I do have a snap on versus scanner which should give me a reasonable level of information. Is the +/- 3 just on the numerical value given by the scanner? I’m not all that familiar with reading live data to diagnose faults!

It’s a 2011 with around 120,000 on the clock.

I did see the Facebook group and noticed there were quite a few Aussies on there whereas this forum seems to have a lot of US based users. Toyota didn’t sell many 200 series in the UK as it was clearly deemed not pretentious enough, compared with a Range Rover! So UK based knowledge is scarce.

Many thanks for your help!

 

[Workhorse]

The injector reading will be fairly obvious with regard to limits. Typically they show between 1-2-ish. If there is one that is way different than the others, keep an eye on it. It sounds like your scanner will read injector values, make note of what they are cold and then when up to operating temp. There may be subtle differences but you will definitely see if one of them is out. Sometimes the faulty injectors make more noise too.

 

[Fisher23]

I don't have a LC diesel, but other diesels.. sounds like an issue with the high pressure pump.