# E36 M51D25 high pressure fuel pump issues



## KabeTabel (May 20, 2018)

Hello!

So i'm having trouble with my e36 325 td. Basically fuel reaching to the injectors but it is getting to the high pressure fuel pump.
Things to remember! Previous owner blocked off egr, made a straight pipe with a resonator, increased the fuel pressure by tapping on the high pressure fuel pumps head, increased boost pressure.

It all started slightly after mid of april. I did a roadtrip (around 400km or 250miles). When I got home, the engine was running good, no issues. The next morning I went to fire it up, started as usual but when it fired it sounded like a babys rattling toy. Turned it off. Checked fluids, everything was okay, dipstick showed engine oil about half way so I filled it up to max just to be extra safe. Turned it on, still same. Let it warm up in my drive way, it got quieter and when I drove it to work (about 6 miles) it was noticeable but quiet but not normal. So I thought that maybe the clutch bearing went and it was rattling. As I drove it more I noticed that it was down on power as well and started to smoke more (from the exhaust). 
Getting towards the end of april (last week I think it was). My friend and I checked under the hood and noticed that the fourth injector (the one with the sensor) was leaking, had a puddle of diesel around it.

Fast forward to the end of april or beginning of may. It's still the same. Started my car, ran just like it did, rattling and slightly smoking and terrible acceleration. Gave a friend lift home and got home. Next morning I go to start it up to take my girlfriend home and it started really bad, like it's almost running but not quite, so it's shaking like hell and finally (after 4-5 seconds of cranking) it fired up, didn't want to idle on its own for a few seconds so I held down the throttle (at around 1500rpm). Looked out of the rear view mirror and saw a big cloud of smoke and even louder rattling. Got to my girlfriends house, stopped and saw that the smoke was white so called the same friend who noticed that the injector was leaking and he said that the turbo was blown. Luckily I had an E39 525TDS turbo laying around (picked up for 20€ on the roadtrip). So I thought that maybe the turbo bearing was making that rattling sound and so I swapped it at home. Fired it up after swapping it, and still the same but not blowing white smoke from the exhaust anymore, just black. So I thought that if it's down on power then there must be too much fuel or too much air. Because I swapped the turbo I thought that there's not enough fuel. (old turbo had back and fourth play in the shaft)
Bought used injectors that came off of a working engine. Went to a friends workshop to swap the injectors and engine just died and wouldn't start up anymore. Called a tow truck and got it towed there. Swapped the injectors (4th was leaking really bad, had a puddle around it. 2nd and 3rd started to get moist). After trying to start it it finally fired up and held it running by holding the rpm at 1500 but then it died on its own, still made that rattle sound.

Got it running last week for a few seconds again. There's a wire that is supposed to be attached to a solenoid or a post on the high pressure pump (friend held the wire against the post then it ran, let go of it then it died. Didn't get it to run again anymore). For a few seconds of starting it wants to start then it just cranks but doesn't fire. Now it just cranks, doesn't even try to start up.

Things I have done to it.
- Changed fuel filter
- Changed 2nd, 3rd and 4th injector
- Changed the high pressure pumps top part (4 bolts)
- Attached the wire to the solenoid or post on the high pressure fuel pump
- Swore at it and listened to sad songs in the car
- Charged the battery

So far I've found out that fuel is reaching to the high pressure pump but from there it isn't reaching to the injectors. 
I have not checked the relays but all of the fuses under the hood are good. fuel pump in fuel tank is working (made sure by removing the hose that goes from the filter to the high pressure pump).

Suggestions on what to try or check are appriciated.


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## Boo_S62 (Mar 7, 2015)

*ECU diagnostics*

Hiya there fellow Diesel friend 

Sad to see no reply's so far, but I have the exact same car, without any issues though. Have you tried to diagnose the ECU maybe check the error codes? Or do you have an ECU at all? Mine is converted to a fully mechanical pump and she works like a clock, if you are running the stock pump, there is a high chance that the 4th injector is giving you issues on reading or is simply a TDS injector and won't go along with the TD ECU. If you find anything let me know and you can PM me if ya need more info, I'll be more than glad to help a fellow diesel lover


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## edycol (Jul 8, 2015)

KabeTabel said:


> Hello!
> 
> So i'm having trouble with my e36 325 td. Basically fuel reaching to the injectors but it is getting to the high pressure fuel pump.
> 
> ...


This is US based forum. That engine was never available here, that is why you don't have answers.

Sent from my iPhone using Tapatalk


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## 76FJ40 (Apr 7, 2021)

Boo_S62 said:


> *ECU diagnostics*
> 
> Hiya there fellow Diesel friend
> 
> Sad to see no reply's so far, but I have the exact same car, without any issues though. Have you tried to diagnose the ECU maybe check the error codes? Or do you have an ECU at all? Mine is converted to a fully mechanical pump and she works like a clock, if you are running the stock pump, there is a high chance that the 4th injector is giving you issues on reading or is simply a TDS injector and won't go along with the TD ECU. If you find anything let me know and you can PM me if ya need more info, I'll be more than glad to help a fellow diesel lover


Hi,
I recently bought a 725TDs for the motor, runs great, only 225,000 kms on it. We are putting it into a 76 FJ40, I would like to put in a mechanical injector pump so I can bypass all electronics... What pump did you end up finding worked for you?
Thanks,
Paul


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