Hello my friends, I am looking for ideas with a problem I am having with my 1990 Daimler Double Six (Japanese Import).

It was running OK, but seemed a bit fuel starved when cold, so I put a new Coolant Temp Sensor in it. After that it fired up like a demon and went like a bat out of hell to the end of the road, popped and died. I assumed I had broken the connection in the process of fitting the CTS, so I put a new connection on.

With the new connection, it was definitely better and the cold running issue is gone, but it once warmed up, it was missing under load and started to cut out when driving, so I got the more expensive CTS from SNG Barratt and put that in. It is now worse than ever. It will cold start and run until it warms up, then it splutters and dies. I can only drive it as long as I don't press the gas pedal. Any demand and it dies. I killed both old CTSs taking them out, so can't revert back to the originals as a test.

I noticed the fuel pump was very load, so I've replaced it with a new Bosch one (also very loud after it's first minute in use). At the same time I put in pre pump filters and checked the fuel tanks for water, I'd say there was some water in one tank, so I drained both and put new petrol in. After this, there is no change at all. Cold start fine, leave it to tick over and it will die once warmed up. When it is running, I can't rev it over 3000rpm and there's no chance of driving it under any load at all.

I'd love to sort this out, old Winston is my very favourite car and I even drive him in winter sometimes..

Cheers
Paddy

 

The 'could be' list might get a little long.

But first......

Since the warm running problem (apparently) didn't exist prior to your temp sensor tribulations you might have a case of 'fiddle factor'. That is, something (old brittle wiring in particular) was inadvertently disturbed in the process of replacing the sensor. It happens all the time. I'd back track very carefully and examine everything that was touched.

Also, in the process of replacing the coolant sensor did you unplug the air temp sensor? if so, make sure you didn't mistakenly mix-up the connections.

Cheers
DD

 

Yeah, I've been looking out to see if I disturbed something else. I did take both connectors off and was sure I put them back the right way, but I haven't tried swapping them, so I will do that, thanks!

 

Resolved! (Hopefully)

I had assumed my problems that followed the replacement of the CTS were related to that. I had suspected water in the fuel as one of the tanks was surprisingly full and later discovered a blocked drain at one of the fillers. I think the water contamination has been building as an issue over time giving the symptoms which got worse and worse.

I drained the tanks again, put good petrol in and pumped it through at the rail - it came out cloudy and didn't smell as potent as the stuff that went in. I collected samples in a water bottle to compare to the goods stuff until it improved. I got it started with an awful misfire but left it to run until the cat was glowing hot, then let it cool. I repeated this a few times and now the misfire has resolved car is better than I ever remember.. Not done a cold start yet with the cleaned up fuel supply, but I am pretty sure that issue was resolved with the CTS.

Hopefully this helps someone at some point..

 

Change the main EFI filter, and do it again in a weeks time.

Keep a close eye on those Pre Pump filters, they will clog very quickly, and reek more havoc.

Good job on the search and solve.

 

Good work!

If by chance you're wondering how your gas came to be water contaminated, check the rainwater drains at the filler cap pockets,

Cheers
DD

 

Ah yes, I should have explained that. I did have a clogged drain on the driver's side. I had also found one of the caps open and although the car was garaged at the time, I don't know how long it had been open for and where it had been.

Now my fuel is pulling from the left and returning to the right (when right selected), so I guess I have crud in the changeover valve. Imagine the joy if these V12s really did fill themselves up like that for free?

That's my next job. I got 2 sets of filters so I can change them all quickly. I couldn't find any clear pre pump filters big enough for the hose (about 15mm), so I am guessing on those a bit.