Diesel hard to start hot.

Hi all, my first post here. Have a '06 4.2 TD intercooled with 175000 km. Starts fine when cold or luke warm, once up to operating temp., often starts only after about 30 secs. or varying degrees in betwen. Has power to glow plugs, fuel filter primer is full. Will fire immediately if turned off and back on, but not after any significant period. Has heaps of grunt, so not a compression issue. Not overfuelling as no chaff out the back on acceleration. Emits white fumes ( unburnt fuel) on startup after long cranking episodes. Once it fires, settles down immediately. Any ideas??:(

G/day Pat welcome to the forum mate & don't forget to stop at introductions & tell us a bit about yourself.

I can't help im sorry to say but your topic is an interesting one cos this is not the first time I've read about this.
One guy I read about has had his back to Nissan a number of times with the same issue & he reported Nissan as saying a number of times that thay could not find anything wrong with his truck so I hope someone here can shed some light on it for you.

Cheers
Paul

Could be a timing issue or a slow starter mate.

I'm thinking possibly the starter, as a quick tester you could take it apart, grease it and try that first and let us know.

There's a few other things that could be possibly causing it but as a quick test method, try that and let us know Pat.

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Originally Posted by Andy

Could be a timing issue or a slow starter mate.

I'm thinking possibly the starter, as a quick tester you could take it apart, grease it and try that first and let us know

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Reckon I can rule that one out. It has a brand new 710 CCA battery cranks well and is starting straight up cold. And I mean COLD. Try -2C yesterday.

mmm....What about the injector pump?

When she's hot and you know It's going to struggle to start again slowly pour cold water at the back of the injector for a minute.

Pretty sure 4.2's are mechanical not electrical.

If it starts straight up or much quicker then it normally does when its hot you may have issues there.

Could be worth a shot anyway mate for a bit of trial and error.

It's going to be an elimination process unfortunately Pat.

Anyone else is welcome to throw ideas in???

Took the truck to professionals last week. No fault codes came up, all were subsequently reset. Further delving discovered that the glow relay was not activating when engine was warm. They managed to get it apart, despite it not being a serviceable unit, and found a wire broken going to the coil in the relay. Soldered up and all good!! Important to note that glow plug indicator light gets its power from a different source to what goes to the plugs !

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Originally Posted by portal pat

Took the truck to professionals last week. No fault codes came up, all were subsequently reset. Further delving discovered that the glow relay was not activating when engine was warm. They managed to get it apart, despite it not being a serviceable unit, and found a wire broken going to the coil in the relay. Soldered up and all good!! Important to note that glow plug indicator light gets its power from a different source to what goes to the plugs !

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Thanks for getting back to us mate.

There's been a few relay issues from people lately, another thread here recently was the battery relay and it took Nissan techs a week to figure it out.

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Important to note that glow plug indicator light gets its power from a different source to what goes to the plugs !

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Interesting...Not the best idea when trying to isolate problems.

It's an old thread but I have recently purchased an 06 4.2 flat tray and I'm having the same trouble. Mainly it takes longer to start when it hot. The plunger is tight to pump and even when pumped a few times it makes no difference. I just serviced it and replace the fuel filter with a new ryco so it's good quality there. After it finally starts it blows a little bit of smoke but not heaps. Someone help cause I'm buggered if I know

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Originally Posted by Tassie4wder

It's an old thread but I have recently purchased an 06 4.2 flat tray and I'm having the same trouble. Mainly it takes longer to start when it hot. The plunger is tight to pump and even when pumped a few times it makes no difference. I just serviced it and replace the fuel filter with a new ryco so it's good quality there. After it finally starts it blows a little bit of smoke but not heaps. Someone help cause I'm buggered if I know

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My Patrol has gone now but I sussed what the problem was with mine eventually and it was expensive. When the IP gets hot tolerances internally get loose to the point where it won't pump hot diesel from a starting position. This is because the viscosity of the diesel drops as the temperature of the fuel rises. It can cope once running but won't pick it up from a stop. When the motor is cool, viscosity increases and all seems good......till next time!!! The only cure is an IP pump rebuild, and throw in some new injectors whilst at it. Bloke in Devonport did mine,can't remember the name. Another point-make sure pump is correctly times when re-installed. Most are not and it makes a huge difference. Think factory is .62 and safe improvement is .70. Can't stress this point too much. Good luck mate.

Hmmm, hope not Pat.

Im having the same issue with a zd30. Only started having the problem after replacing injector pump with a rebuilt unit, new injectors and new glow plugs. Starts fine when cold but hot can turn over for what seems like a very long time before it starts with a puff of white smoke. All good once its going though.

Where is the glow plug relay located and where can i get a replacement? Original equipment only?

Mickn

Thanks portal pat. Is there any way that I can test if that is the problem. Even when I press the priming pump a few times it still takes a bit to start, I would have thought that this would pressure the fuel system and (help) the pump in some way if that was the same problem as yours. If that is the problem it sucks, I have a few more things to check first and hopefully I find out it is something minor.

Mine behaves pretty much the same since I've had a brand new 12mm pump put on. Seems to start fine when cold but cranks for ages when hot or been sitting for an hour or two. Mines got a manual glow and never used it when hot or warmish with the old pump and it always started like a champ. Now it doesn't make a difference to glow it or not when warm.

Cars been back to shop a couple of times already to stuff around with the pump but probably needs to go back again. Not sure if i have i hopes in getting it to behave nice or not starting to get a bit over it to be honest. . .

Originally thought it might have been a trade off of a 12mm pump but after seeing mudskis in action his doesn't miss a beat. Haven't had many others to compare it to tho (12mm pumps). Is this likely to be an issue with pumps once you start tweaking them ?

I wonder if using an electric lift pump would help your problem Rossco?

That's what my mechanic said to do. If the plunger is tight and you still give it a couple of pumps and it takes a bit to start again doesn't that mean the fuel pressure is eliminated. Maybe another option is a one way valve to be sure, cheap to buy one and then you can be positive there is no leaking back of diesel

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Originally Posted by Tassie4wder

Thanks portal pat. Is there any way that I can test if that is the problem. Even when I press the priming pump a few times it still takes a bit to start, I would have thought that this would pressure the fuel system and (help) the pump in some way if that was the same problem as yours. If that is the problem it sucks, I have a few more things to check first and hopefully I find out it is something minor.

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I even fitted a lift pump when I was searching for a solution, to no avail. Could only suggest you douse the IP in cold water and see if lower operating temp. then helps it pick up the fuel.Cheers.

Ha bugger that's kind of not what I wanted to hear. Just started the ute up from dead cold and it wanted to play up a little bit, I am going to test the glow plugs and go from there even though when the car is at operating temp the glow plugs shouldn't play a part of stating the ute, or am I wrong in saying that

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Originally Posted by Tassie4wder

Ha bugger that's kind of not what I wanted to hear. Just started the ute up from dead cold and it wanted to play up a little bit, I am going to test the glow plugs and go from there even though when the car is at operating temp the glow plugs shouldn't play a part of stating the ute, or am I wrong in saying that

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I would say your right in saying that. Mine has manual glow (just a button) and used to start fine without them, you would only have to use them first thing in the morning. You could even start it straight up on a hot day without using them.

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Originally Posted by Winnie

I wonder if using an electric lift pump would help your problem Rossco?

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Thought about that but kinda thought that it shouldn't really need it just for starting they're more for high hp where you need the extra fuel delivery. Also thought about little one way valve, however in theory both of these things would make it hard to start cold too (not having them fitted).

Having said that it is worth a try but thinking it's something in the pump.

Ring Omar mate he'll KNOW or swap out that pump and start again

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Originally Posted by roofy

Ring Omar mate he'll KNOW or swap out that pump and start again

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Yeah not a bad idea. I know what he'll say, just put a big V8 petrol in, he likes his petrols. He's got a td 42 GU ute but didn't have to much good to say about it, not enough power for him!

Yeah thought about swapping pump out but it's a fair bit of money down the drain and can't quite afford it atm. Would be good to see how some other 12mm's perform, if AB and chappy gets their ones up & running be interesting. Remember talking to the guys at racebred looking at their race truck. They said it was temperamental to start but that was a highly tweaked td.

What has Andy at diesel tec said about it? Does he think it's normal?

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Originally Posted by Rossco

Yeah not a bad idea. I know what he'll say, just put a big V8 petrol in, he likes his petrols. He's got a td 42 GU ute but didn't have to much good to say about it, not enough power for him!

Yeah thought about swapping pump out but it's a fair bit of money down the drain and can't quite afford it atm. Would be good to see how some other 12mm's perform, if AB and chappy gets their ones up & running be interesting. Remember talking to the guys at racebred looking at their race truck. They said it was temperamental to start but that was a highly tweaked td.

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surely there must be a way of doing it MayBE tweek it back a ciggy paper thickness sounds like trying to set the boost
on a 3l you either get it or not
it all has to do with pressure and you have to keep it on could be just that bit to forward and needs to go back
as above

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Originally Posted by Tassie4wder

Ha bugger that's kind of not what I wanted to hear. Just started the ute up from dead cold and it wanted to play up a little bit, I am going to test the glow plugs and go from there even though when the car is at operating temp the glow plugs shouldn't play a part of stating the ute, or am I wrong in saying that

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Is it the original engine and original injector pump and injectors?

Is there a black box on the back of the injector pump?

Have you tried the cold water suggested earlier and what was the result?

It does sound like the injector pump is the culprit.

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Originally Posted by Rossco

Yeah not a bad idea. I know what he'll say, just put a big V8 petrol in, he likes his petrols. He's got a td 42 GU ute but didn't have to much good to say about it, not enough power for him!

Yeah thought about swapping pump out but it's a fair bit of money down the drain and can't quite afford it atm. Would be good to see how some other 12mm's perform, if AB and chappy gets their ones up & running be interesting. Remember talking to the guys at racebred looking at their race truck. They said it was temperamental to start but that was a highly tweaked td.

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This is no good. Take it back to diesel-tec and get him to remove the pump and repair it. There is obviously something wrong internally that wont be able to be fixed on the car. If a 12mm is built correctly it will work as any other pump does. The later toyota 6 cylinders came standard with a 12mm. Even that comp truck guy probably needs some work done to his although at the rpm range he is using it most of the time it probably doesnt matter to much.

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Originally Posted by nissannewby

This is no good. Take it back to diesel-tec and get him to remove the pump and repair it. There is obviously something wrong internally that wont be able to be fixed on the car. If a 12mm is built correctly it will work as any other pump does. The later toyota 6 cylinders came standard with a 12mm. Even that comp truck guy probably needs some work done to his although at the rpm range he is using it most of the time it probably doesnt matter to much.

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Cheers Matty, that's kind of what i wanted to hear. I'll get in touch with Andrew again see how we go, hopefully we'll. I did ask him last time it was in, he said to see how it goes and let him know. Kinda hard being busy and all . . .

Kind of? ....

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Originally Posted by nissannewby

Kind of? ....

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I think he means your comment on the pump being the issue and needing someone to agree and not possible other reasons flying around his head at the moment no doubt.

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Originally Posted by Rossco

Cheers Matty, that's kind of what i wanted to hear. I'll get in touch with Andrew again see how we go, hopefully we'll. I did ask him last time it was in, he said to see how it goes and let him know. Kinda hard being busy and all . . .

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Hey Rossco I can run around for you mate
and anybody else who needs a hand just let me know

Yeah good to know for sure that it's not right, not just a 12mm trait. Is just a bugger as it's gone back in the shop a couple of times already, feels like it's been a pretty lengthy process to get it right.

The latest thing I have done is spat the dummy with it and pulled the injector pump out and taken it to Alberts diesel in Launceston to have it rebuilt. Little bit costly I think but I will find out the price tomorrow and hopefully when I put it back in it fixes the problem( fingers crossed)

Right so I have had the injector pump rebuilt. Put the pump back in and dialed in it in at .72 which was as close as I could get it. It still seems to wind over about 5 or 6 times before it starts when hot. I'm thinking the lift pump now. The pump was worn a little so Alberts diesel said, so it was a good move to get that fixed and it is a little better to start but still not perfect yet.

Grrr bloody annoying, good luck with it. Good to see how the lift pump goes, hopefully well.

Haven't touched mine yet, should get round to it soon, been a bit busy. . .

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Originally Posted by Rossco

Grrr bloody annoying, good luck with it. Good to see how the lift pump goes, hopefully well.

Haven't touched mine yet, should get round to it soon, been a bit busy. . .

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Wow Rossco. You still having issues with your pump?

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Originally Posted by mudski

Wow Rossco. You still having issues with your pump?

Sent from my SM-P600 using Tapatalk

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Yeah still temperamental to start, sometimes good but most times takes a fair bit. The running away issue is sorted but need to take it back again to hopefully get it to start nice. Might try and get into it this week maybe.

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Originally Posted by Rossco

Yeah still temperamental to start, sometimes good but most times takes a fair bit. The running away issue is sorted but need to take it back again to hopefully get it to start nice. Might try and get into it this week maybe.

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I keep meaning to ask JPC about why there is a one way valve inbetween the filter and pump. I know what it does, but why....
Bugger about the starting issue.

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As far as I know the reasons for fitting a one way valve are either to prevent a loss of prime, usually an attempt to stop fuel draining back to the tank because of either a hard to locate air leak, or a worn pump. (It may be possible that some pumps are not designed to hold prime & thus require a one way valve to be fitted) , or just to make the process of priming easier.

Slight leak in on of the injector lines. Tightened it up and double checked the bolt where we put the dial gauge in which some how we didn't put the copper washer in. So I bent my arms In some funny ways yet again and got the bolt out put the dam washer on it and I think it is fixed. I will know properly in the next day or so about the starting issue as for power I intend on taking it for an outlet run which before I could get 100 in 4 th to get up the hill comfortably. It will be interesting to see if there is a slight gain with the pump rebuilt and the timing at .72

Little bit of power increase from advancing the pump but not much. It still had starting issues so a mate of mine which is a diesel mechanic and is also smart with power in cars put an ameter on the starter motor, he also checked a couple of other things on the starter and came to the conclusion that is might be tired so we put another one in and problem solved. Starts like a gem now