DG Hot Start Problems

[zoona]

I have been having hot start problems since I got this van. I think I have found the culprit, but not sure how to fix it.

Cold start has always been on the button, however hot start often takes quite a bit of cranking to get it to start.

3 times we have been on long drives, stopped to go and do something and then tried to restart it (less than 30 mins after shutting it off) and it has just cranked and cranked.

The first two times, i called out our breakdown, and they got it running again - there was no conclusive action that made it work. In both cases however they did use some magic spray to get it to catch (and confirm that fuel supply was the issue)

I initially thought it was a fuel supply problem, and when taking the tank out there was loads of "pooh" in it. rust and gasket material.
I replaced the tank and the fuel lines in the engine bay, and things seemed to be better.

In the mean time i rebuilt the carb (as it was dirty, and I wanted to see how it worked...). Put it all back together again, and while the cold idle is a bit low and the hot idle is a tiny bit high, it has all been running ok.


Just been away for the weekend. 3 hour drive home, up some mountains and stuff. GOt back, emptied the van and started it up (about 30 mins after shutting it off). Started after the normal hot starting amount of cranking, then 100m up the road just died.

I left it there, came back here and did some googling, and found all sorts of potential issues - but the one that sounded about right was vapour lock.

Went back to the van and did the following:

• Pulled pipes of either side of the fuel pump - bone dry
  
• Took the top off the fuel pump - a tiny bit of fuel in there
  

This made me think the vapour lock thing was right.

I then drained a bit of fuel from the tank, and put it into the carb.

When i turned it over, it caught and then died.

When i then tried to start it normally, it worked...



I found a load of threads that talked about vapour lock, but i can't really see a solution other than pulling it apart and trying again. which is not practical.


So my questions for the class are:

• Do you agree that this is the problem?
  
  • Sub question - if not, what do you think it is/what else should I check?
    
• If so, what is the permanent fix?
  

[DoubleOSeven]

My hot starting issue was failing starter motor, but yours is fuel pump as it stalled whilst driving. It may be both. I’m working on a similar issue and after borrowing a fuel pump proved this was my stalling issue.

[Mocki]

Went back to the van and did the following:

• Pulled pipes of either side of the fuel pump - bone dry
  
• Took the top off the fuel pump - a tiny bit of fuel in there
  

This made me think the vapour lock thing was right.

have you pictures of the fuel pump ? 
 

[zoona]

Went back to the van and did the following:

• Pulled pipes of either side of the fuel pump - bone dry
  
• Took the top off the fuel pump - a tiny bit of fuel in there
  

This made me think the vapour lock thing was right.

have you pictures of the fuel pump ? 
 

https://photos.app.goo.gl/WTCkCQzkBnE2Zb3c6

This is it... I have seen there are different types (aka quality) of pumps. Is that why you are asking?

[Mocki]

No I was just interested in the type of pump that you could take the top off, normal T25s mechanical pumps you cannot 

the pump looks new, is the push rod new too ? 
( must be 100mm in length ) 

I changed to a electric pump and stopped all the guess work with petrol ! 

[zoona]

No I was just interested in the type of pump that you could take the top off, normal T25s mechanical pumps you cannot 

the pump looks new, is the push rod new too ? 
( must be 100mm in length ) 

I changed to a electric pump and stopped all the guess work with petrol ! 

Yeah, i saw this was an alternative, but they don't let you modify things here in Switzerland, so I'm not sure it would be allowed... I am going to find out as this looks like a decent option.

I haven't seen an idiots guide to replacing with an electric pump anywhere. Do you know of one?

Is there a specific pump I need to buy? I saw mention of a Facet pump?
Presumably, you just run it from the tank to the carb, and set a certain pressure? But with new lines, removing the hard lines?
Pump lower than the tank?
It's mainly the control I would be worried about I e. It not running in an accident...

[Da dan]

Facet pump yes. Just a few inches away from the tank and mount it on a rubber mounting to keep it a little quieter. Mine was the same till the hot and cold starting became erratic and finally didn’t start.


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[Mocki]

You don’t remove the plastic petrol pipe, just install the pump just after the filter and run a short piece of rubber in the engine bay direct from the baulkhead where the plastic ends to the carb . 

the wiring is simple enough , you need a pos down to the pump from the engine bay from a relay triggered by Either the oil pressure switch or the alternator ( so if the engine stops the fuel pump stops ) and you make the neg connection to the chassis . 


 

[zoona]

You don’t remove the plastic petrol pipe, just install the pump just after the filter and run a short piece of rubber in the engine bay direct from the baulkhead where the plastic ends to the carb . 

the wiring is simple enough , you need a pos down to the pump from the engine bay from a relay triggered by Either the oil pressure switch or the alternator ( so if the engine stops the fuel pump stops ) and you make the neg connection to the chassis . 

Ah, so the existing fuel pipes are good enough?
And on fuel pressure, is that a case of picking the right pump that outputs the correct pressure, or do I need to get a regulator and adjust it?
Still not sure if i am allowed to do that here - so going to brave the local DVLA equivalent and find out.

In the mean time I am going to check the fuel pump push rod. 

Thanks for all the help.

[davidoft1]

Have you changed any ignition parts , that rotor arm looks pretty doggy, hows the cap etc?

[zoona]

Have you changed any ignition parts , that rotor arm looks pretty doggy, hows the cap etc?

No, but I do have another rotor arm waiting, just keep forgetting to put it in when the van is here (we keep it a few miles down the road in a barn)

I want to try to sort one thing at a time so I know exactly what the problem is. But will definitely look at that as well.
I think given the dry fuel lines, I am now in to the right thing... I hope.

[Mocki]

This pum,p,works fine , no regular needed 
I have had one on my van for years , no issues 
https://www.ebay.co.uk/itm/380369295080

[zoona]

This pum,p,works fine , no regular needed 
I have had one on my van for years , no issues 
https://www.ebay.co.uk/itm/380369295080

Right, I am going to investigate the legalities here, and aim to fit one.

I think one could easily tuck it away and pretend the mechanical one is still in use anyway...

I am in the verge of selling it because of this problem letting us down do many times, and now not trusting it... I really don't want to...

[maxstu]

Ive a fuel pump l can send to you to try before buying, Ian?
Also agree with Davidoft1. Get rid of the 5400 limiter rotor arm and fit a normal one for a test period.
Can a DJ fuel injection pump be used? Ive a spare you can try..
Regards
Stuart

[Mocki]

Can a DJ fuel injection pump be used? 
Regards
Stuart

No, too much pressure and too big bore size for a non injection tank .... sadly