Hi all.

Guys, re my last ongoing issue with my 96 DSE P38 not starting.. As you may or may not have read i was so close to giving up..The car would randomly not start when hot, but fired ok when i poured cold water over the deisel pump..... I already had a Hot Start Fix Box fitted from Ebay. Car pulls fine, when running and always starts first time when cold with no smoke..

Ive changed Leak off pipes, Glow Plugs, Battery, Filters etc..And still same issue. Yesterday i changed the Hot Fix Box for a brand new one incase it was breaking down... This morning it started first time, Revs remained high for 30 seconds then dropped to normal, drove as good as.. Stopped 10 miles away to fuel up and got the non starting problem. Poured over 5 litres of cold water over the fuel pump, and started straight away.

The hot fix start box breaks a (grey/blue) single wire from memory, which i pressume is the wire from the sensor in the pump? Is shorting this to earth, or feeding it 12v live (via a flick switch) going to trick it into thinking the sensor is reading cold (hence doing the same as cooling the pump with water)?

Any advice would be greatly appreciated.
LTel

Boydonegood said:

Hi all.

Guys, re my last ongoing issue with my 96 DSE P38 not starting.. As you may or may not have read i was so close to giving up..The car would randomly not start when hot, but fired ok when i poured cold water over the deisel pump..... I already had a Hot Start Fix Box fitted from Ebay. Car pulls fine, when running and always starts first time when cold with no smoke..

Ive changed Leak off pipes, Glow Plugs, Battery, Filters etc..And still same issue. Yesterday i changed the Hot Fix Box for a brand new one incase it was breaking down... This morning it started first time, Revs remained high for 30 seconds then dropped to normal, drove as good as.. Stopped 10 miles away to fuel up and got the non starting problem. Poured over 5 litres of cold water over the fuel pump, and started straight away.

The hot fix start box breaks a (grey/blue) single wire from memory, which i pressume is the wire from the sensor in the pump? Is shorting this to earth, or feeding it 12v live (via a flick switch) going to trick it into thinking the sensor is reading cold (hence doing the same as cooling the pump with water)?

Any advice would be greatly appreciated.
LTel

Click to expand...

The only temp sensor in the pump is the fuel temp sensor. Far more likely to be ECU engine temp sensor fault. That is the sensor the hot start cuts out and fools the ECU into thinking the engine is cold.Try fitting a new ECU temp sensor and disconnecting the hot start see what you get.

PS. Clean the multi plug connections to the fuel pump. This multi plug is the interface for fuel temp sensor, fuel quantity servos, a corroded/dirty pin may be the cause of you problems.

Cheers Wammers. Will try clean the plug tommorow. I seem to have the hot start problem every time I stop now. Even tho I have the hot fix box fitted. Even pouring cold water isn't as effective anymore and have to leave it till goes cold. Dreading it may be time for new pump? :0(.
Where do I find the ECU temp sensor mate? Having trouble finding one for sale too. Am willing to try anything now
Thanks. Tel

I did a lot of research on this a few years back when I had some hot starting problems. In my case it was the in-tank fuel sender pump that was gone, but from the research I did the cold water test indicates a worn out FIP. The hot start fix won't really solve it.
Apparently the real source of hot starting problem is wear in the fuel pump. The hot start fix addresses some of the issues by sending the pump onto a cold fuel map, timing with the bonus of heater plugs.
But if it starts after pouring cold water on the pump but not with 'hot start fix' it indicates that the wear has gone beyond that stage.
By cooling the pump housing but not the internal components (ie pouring cold water over the pump) you are closing up the internal tolerences around the rotary stage of the pump, thereby increasing the pump pressures.
Interestingly,another remedy proposed when wear reaches this stage is to pour straight veggie oil into the diesel tank to increase the viscosity of the fuel going through the pump thereby achieveing a similar increase in pump pressure. I haven't reached that stage myself yet so can't comment on the effectiveness/ side effects but it makes a pretty logical argument.

Spudh..........i run my dse on biodiesel...not quite as thick as straight veg oil but thicker than dino....if i run low on bio its a twot to start when hot!

everlatesparky said:

Spudh..........i run my dse on biodiesel...not quite as thick as straight veg oil but thicker than dino....if i run low on bio its a twot to start when hot!

Click to expand...

So, are you saying that when you are low on bio, you are running a higher percentage of standard diesel and when this happens you are back to hot start problems?
Seems there is truth to the remedy, interesting

BTW I wasn't suggesting running on straight veggie in case anyone runs out and buys a crate of the stuff, just maybe 10 or 15% max.