Diesel Hot Starting Fault P38

I am so impressed that you boys are stillploding on with this mod, not so impressed with the person now selling the plans on ebay that i gave for free to help you guys out feel a bit robbed or is it stupid that i did not think of it ha ha

First off well done for sussing this out, its almost there now,

Lets hope we get a definitive answer on this, as its a little confusing (especially for me)

so you have established that a 2k2 resistor is needed thats fine (from Maplin)

you have all the [SIZE=-1]circuits[/SIZE] and diagrams done (well done that man)

the relay it a timed one (15-20 seconds) 5 pin and thats where it stops.

but know one says where to get one from (all the suggestions i have seen i have had now joy with) ok there was 1 for £40 but thats a lot of ££ for something that dosn't have to be that complex surely? the Land Rover one was suggested, then discounted as it wasn't man enough for the job, any suggestions for a replacement? as to what amp ratings and part number where to get it from then? all we are waiting for is the correct relay then its sorted

But a great thread and interesting for sure, isn't it good to beat Land Rover and BMW at there own game?

i went to BMW on Thursday and spoke to them about the Hot Start problem they deny that it even exists, all they want to do is stick a diagnostics on it and charge you for what they think it is!! and of course it wont be that, as we all know and i’m sure so do they, shame on them!!

ok i got this


RANGE ROVER 15 SECOND DELAY TIMER RELAY. PART NUMBER 39406E 4087. FITTED TO CLASSICS FROM MID 1980s

And this from Maplin Maplin > Metal Film 2W Resistor

when i fit it i will tell you if it works so now you have a part # for the timer relay and where to get it from (any Landy Main Dealer) and a sorse for the 2k2 resistor (18p)

Metal Film 2W Resistor

I found this in my DURITE catalogue. part # 0-743-12 its rated at 10w (is that ok?)

Interior light delay 12v. four terminal connections. gives 10 delay to interior lights, universal connection

pin 1= door switch
pin 2 = + feed
pin 3 = earth
pin 5 = side of lamp

It has 4 pins (not 5)

I spoke to some tec guy from DURITE and he says it will do the job, but wasn't sure about the wattage because he didn't know what i was splicing in to, i told him it was interrupting a sensor, and he said it was probably ok then

can someone help me out with what pins i put the resister on and what wires i splice it in to Please? and any other advice you might have

thanks again all

Not sure if this has already been mentioned but In last months (July issue) of LRO magazine about hot starting problems on the BMW engine, the most likely cause is the fuel tempature sensor, to proove this carry a five litre container of cold water around in the car and a wide angle funnel, next time it will not start hot, pour all the water through the funnel directing the cold water over the fuel injection pump, if the car starts after that then it is the fuel tempature sensor and replacing this is a feasible DIY repair as the pump does not have to be removed to do the repair, but the inlet manifold does need to come off.
Hope this helps.

Jim

thanks for that Jim, But read this from offroadbaz page 12

I changed the fuel temp sensor in the pump yesterday, cost £14 including the top gasket. Just ring any bosch specialist with your pump number ending in something like 993, 994 or 995.

Easy job, just had to remove the inlet manifold and modify a 7mm socket to fit the Bosch security bolt.

The result......... Made no difference to cranking time when hot.

Back to scouring the internet for a fix as opposed to a workaround.

Click to expand...

and a few others have tried replacing the fuel temperature sensor with no success, i’m not saying it isn’t the fuel temperature sensor, but when tested and working fine, it seems the "hot start" is the way to go, i pulled mine out and it was still a pig to start up, so in my case it wasn’t the fuel temperature sensor

Hi all an update for anyone who is interested a friend of mine has done this for me/us have a read (if your interested) of this thread Range Rover Poor Starting a good few people have tried there best to find an easy and cheap solution to this (including people on this forum) many thanks to you all, but it probably can be improved slightly i will keep you all updated with any more progress if and when it happens

Its best if you load it on to your computer and blow it up a little more

From my friend Jason

"I managed to knock this up last night. I do not begin to understand what this fix is fooling but this is a layman’s interpretation of how to install the fix in the above scanned write up. I have also included a version with a timer in. I am not sure as to the need for the timer as i would have thought the Red/White wire from the glow plug is providing the timer function. Would be nice if somebody could have a check over to see if i have made any glaring mistakes."

Hi,

mode with 2K ohm resistor is good, but it is not for long time.

Whole problem with BMW engine HOT Start is faulty electronic in High pressure diesel injection BOSH pump. Mechanically is undestructable, but Electronic part is real problem.

1. symptom is this, HOT Start problem.
2. symptom is this, Engine have bad idle, rpms are going up and down
3. symptom is this, When you drive with specified rpms ( 1500 rpms ), constant pressed accelerator, car cannot drive in constant speed.

This problem can be solved permanetly only when you change electronic part on BOSCH high pressure injection diesel pump.

Sorry for my English, but this is absolutely true. I have Opel Omega with 2,5TDS BMW engine and i have same problem. And now Lande Rover, Range Rover. Same problem and same solution.

This problem cannot be visible on Diagnostics. If everything is good on your car, problem is this Electronic part.

Repair is in Czech Republic very expensive, about 800 pounds.

GL.

Looks Like some bright spark has sorted it (maybe!! ) Hot Starting Fix - Range Rover BMW Diesel - P38 DT DSE - eBay Range Rover, Car Parts, Cars, Parts Vehicles (end time 02-Oct-07 18:00:00 BST)

Hi Guys - Regarding Dopeys post ( number 127) Don't simply try to increase the Glow plug pre heat time because the problem is also that when the ECU thinks the engine is warm it retards the timing, cuts any excess fuel for starting, and also reduces the glow plug timing.
Don't bother with the fuel temp sensor it doesn't cure it - believe me I have done it. Either follow the original Tigapiglet post (with or without the timed relay) or buy the kit from ebay - which is a tidied up version of tigas post with a timed relay built in - if you do buy the kit DO NOT USE the scotchloc type snap connectors - Cut strip and solder any connections - The ECU measures the resistance to set the fuelling for the engine at all times not just starting Scotch locs are notorious for increasing resistance with age which will bugger up your idle speeds later. People who have done Tigas mod and had high idle speeds probably have high resitance connections telling the ECU that the engine is cooler than it is after the relay has cut out

I have just bought the item off ebay and I have to say that I am impressed. For all of £25 you get a neat little box containing the timing circuit and instructions and connectors. I didn't use the connectors but soldered all the joints and covered them in heat-shrink sleeving for a permanent and neat job.
So far so good, it does appear to do the job and for the price, well worh it.

Having read another thread on cold starting problems where it would appear that the rubber injector return pipes would crack or split and allow air into the system and cause a problem, I thought I would check mine out. One of the symptoms is that the car would try to start when you begin to crank it over but not quite catch and would then start after a second go. In reading the thread I thought it described what my car did when cold and come to think of it when warm after being left a couple of hours.
On checking my pipes I found that they were all hard, cracking and some had split. After pricing up the parts at the LR maindealer at £37 + vat I called the local independent LR specialist who cut me the sections of pipe off the roll and charged £7 incl vat! I have fitted them and boy what a difference. The car now starts almost immediately hot or cold. I do think that the hot fix timer relay is a good idea but I would advise that you just replace the return pipes regardless as they are cheap to do and it does make a big difference. My car is a 2001 2.5TD with 64k miles so there won't be all that many P38s' out there that are much newer or with that many less miles on that will therefore not need new pipes!! Mine were in a very poor state so I would recommend you take a look at yours.

just had a 95 p38 2.5 td in our workshop for an elsbett veg oil conversion. previously a pig to start from hot, and totally impossible with the kit fitted and running on diesel. also had no power below 2k, and kept stalling . once filled up with veg oil, she was back to how she should be. I think that as the injectors open at 240 bar , the diesel was leaking passed the pump due to wear. the veg oil, being thicker has certainly made the difference. modern diesel has little sulpher in it , and this has always been the lubricant. take it out and this is what you get, fuel distribution pumps wearing out prematurely.veg oil is a much better lubricant, and a lot cheaper as its tax free for the first 2500 litres/annum.

Hi everyone,
I am new to the site and relatively new to land rover ownership. I have a 4 litre petrol 2000 reg P38 and have frequently experienced "hot start" problems.
Are any of the solutions discussed in this thread likely to be applicable to a petrol engine?

Rathlin said:

Hi everyone,
I am new to the site and relatively new to land rover ownership. I have a 4 litre petrol 2000 reg P38 and have frequently experienced "hot start" problems.
Are any of the solutions discussed in this thread likely to be applicable to a petrol engine?

Click to expand...

In a word, no! What has been discussed here is very particular to the Diesel engine. I'm sure someone will be along shortly to give you some advice on your V8 issues, if they don't then I would start a new thread to attract their attention!!

Thanks for the warning - I'll see what comes up.

Hi Gents
I feel like a bit of any interloper on here .... Ill explain.
I run a 1997 BMW 325TDS touring! It has THE BMW hot start FEATURE!

"They do that sir!"

Reading through all thats gone before I think "bin there done that"!

The clock is at 186K miles in front of an auto box that will not pull top and lock the torque converter until its doing 70mph! So the motor puts the revs in.

It starts brilliantly cold and runs sweetly at all times other than the dreaded hot start "starter motor endurance test"! Once fired BIG smoke plume and the battery heaves a sigh of relief as the alternator re-inflates it!

I have done the temp sensor in the top of the delivery pump too. No change.
Injectors checked OK
Bleed off pipes .. replaced a couple of times but mainly because diesel comes out if air can get in.
Compression checked OK
BMW diagnostic ... mmmm ... "MAYBE a problem with the distribution pump... £1200". Sorry Mr BMW I want better than MAYBE before giving the go ahead.

I have been told ... as the Eastern block correspondent stated in an earlier post, that its a fault in the electronic part of the hybrid Bosch pumps. To be specific, the little bushes of the linear actuator part of the metering unit. This is the next layer down below where the internal fuel temp sensor sits in the top of the distribution pump.

Disclaimer ... Don't try this at home etc..

Once you are into the top for the temp. sensor BEWARE! The next layer down affects the calibration by virtue of its position on the main body. It has larger holes than the bolt diameters so that it can be positioned exactly for the delivery rates. One trick to retain the position (not my idea but posted by the guy in the USA that sells the Bosch security bolt tool!) is to put small blobs of Araldite or paint at each corner. Wait for it to set. then crack the joint and lift the "slice" off. The bits of resin on the removed module and the main body then provide a registration when re-instating.

He has some pictures of the job but I cant locate them just now. Feel free to email direct and Ill see if I can relocate the posts. If anyone is brave enough to go in there I would be please the hear from them?

I was on the brink of putting it in to two places recently but both talked about replacing the pump rather than rebuilding it or replacing worn bits so here I am getting ready to go at it again.

I have just seen the Ebay timed relay listing am may try that as I am CONVINCED A COLD START CYCLE WOULD FIRE IT UP but fear its still a work around for something else? If poor BMW programming why don't they admit it and fix with a remap?

Should the delivery pump run all the time?
What pressure/rate should it deliver?
I was about to cheat that too as I have had it stall after overrun a few times too. One of the ECU features is to cut fuel on over-run but I think its lazy coming back on sometimes when the tank is low?

Can anyone tell me what the purpose of the small pipe from the bottom of the plenum chamber to the transducer/switch(?) by the fuel filter on the inner wing is? Is it a vacuum sensor? I can not see it on any of the RealOEM parts listings?

Happy New Year!
Garry

Garry,

Suggestions - change the engine temperature sensor if you haven't, unless you can verify the engine temperature with diagnostics or by devious means. My Rovacom Lite shows our Range Rover 2.5DSE (BMW engine) water temperature as being 85 degrees +/- 0.6 degrees and that is with a new engine thermostat.

The RR has a clear pipe from the fuel filter to the injector pump - if you had air in you would probably see bubbles there. In tank pump runs all the time as it delivers backto the tank and the delivery target rate on test, if you disconnect the inlet to the fuel pump is 200 ml over 10 seconds.

No separate plenum chamberon my RR as far as I can see. There is an air temperature sensor (IAT) on the beginning of the inlet manifold with an electrical connection for the ECU. There is also a small pipe that goes to an air pressure sensor (MAP) mounted on the top of the fuel filter.

We have a BMW 330D as well so I will not make any comments about BMW main dealer service other than I wouldn't go near them with a barge-pole again, except in an absolute emergency.

If you want your own diagnostics for the 325TD. you can download a 'free' version of the Carsoft diagnostic software on the Internet if you search hard enough. Also Ebay regularly have BMW diagnostic interfaces available which match the Carsoft software.

Richard

Thanks Richard

Ill check the temp output and see whats going on there. I have noted the gauge dropping a bit lately when running light. This after a new water poump (instant failure watch out plastic impeller. ECU shut down saved the head gasket!). I didn't swap the stat. The fault been there much longer than the pump fail though.

No air leaks through the clear pipe... it did have when the spill rail pipes failed. Know about that one hoho.

On my motor attached to the top of the filter housing is a small transducer of some sort with the usual power/signal plug. This also has a pipe to the base of the long chamber after the exhaust gas recirculator that links all the inlets. I suspect its a pressure sensor. I notice this pipe is the same fabric covered type as the spill rail. this has failed under the chamber where it is secured with a factory "circlip". Fabric intact rubber shot. Ill get the part number off it and search now there is daylight!

As regards the delivery pump, thanks ill check it out. I think the ecu cuts it on over run when in top. Its then slow to feed and I get about 10 seconds of "coasting" with the engine check light on before normal service is resumed. Interesting in the outside lane!!!! The first couple of times it came back before I got to the hard shoulder ... now I just stick with it ... ho ho.

Right ... now to locate the diagnostic software ...

Ta!
Garry

[email protected]

Hey K100wig,

Any update on how you got on. My Rangie diesel does exactly the same thing, engine cuts out in top on light throttle on the open road, engine light comes on for a few secs, it coasts and then power comes back and away you go. I've detailed a few of its symtoms in another thread (sorry, don't know how to put link in properly!):

threadhttp://www.landyzone.co.uk/lz/f10/p38-diesel-injector-light-coming-low-power-55459.html

Spudh