Jump to content
SAU Community

Bosch Fuel Pump Lifespan?

Cubes

By Cubes,
in Engines & Forced Induction

 Share

Recommended Posts

Cubes Grand Master

Cubes

Posted
Posted

Hi ppls,

Over the last few weeks I've been experiencing the occasional lean conditions; sometimes when I first start the car other times just out of the blue.

The car will be driving fine then all of a sudden I notice a slight surging at light/moderate throttle and a rough idle; check the pfc's sensor check and see the o2 sensor going lean.

Driving the car it tends to surge a little and feels as if it has a bit of a flat spot at the start of the throttle.

It used to come good once getting up on boost.

A simple pull over and shutdown and restart 9 times out of 10 would get it going smooth again.

Now (today) it began going lean once up on boost and also knocking easy.

Nothing I could do would get it driving nicely again; it would however come and go as I drove; lean then it would smooth out and afr's would return to normal.

All sensors (afm *that is/was new* etc) check out and are reading as they usually do, apart from the o2 obviously.

The external bosch pump appears to to be buzzing away as it usually does however the intank std pump that is well overdue may be failing.

Could the intank pump have failed causing a restriction to the external fuel pump? I'm not sure if that is possible. Maybe...

Do note that I threw the external pump on the car as the std pump couldn't keep up with only 150rwkw at the wheels when the RB20DET was in it running 12psi. That was ermm..... Over 130,000km's ago.

So....... Any one had an experience similiar? The come and go surge/lean conditions that progressively get worse.

I'm going to look at the pump first; if its not that then my first place of call is the PFC. Just a gut feeling.

Link to comment
https://www.sau.com.au/forums/topic/139287-bosch-fuel-pump-lifespan/
Share on other sites
Cubes Grand Master

Cubes

Posted
  • Author
Posted
if you've still got the stock lift pump, then i'm gonna say that its probably at the end of its long life....

My hopes it is also... and not one of those expensive hard to track down bugs. :dry:

are u running with 02 feedback on or off? have u changed the 02 feedback co-efficient?

I've tried with with both; haven't changed the o2 feedback co-efficient.

I've init. the pfc and simply selected vg30 maf and applied inj correction. Still the same. :(

I'll rip off the intanks plate tomorrow and see if I can hear the intank pump working.

Fingers crossed it isn't so its an easy fix. :)

I just came back from a drive then... Its really strange; cold start it was good, 1km down the road it started surging; pulled over did the pfc reset; drove off it was ok for 500m then began playing up again. 10km's later and it came good for another 5km's then went to crap again.

Some times on cruise it will go lean; accelerate a little and it comes up and the o2 begins cycling again; back off slightly and it goes lean. But note that is some times.. Othertimes it simply stays lean then gradually becomes richer again.

Whats strange is if I were to give it a bit it doesn't completely go lean it surges a little then takes off, but I suspect it is going lean a tad as it does tend to det a tad.

Which isn't good. :P

Hope that made sense. lol

FATGTS-R Experienced

FATGTS-R

Posted
Posted

From your details it sounds like it could be the stock lifter has shat itself but it could just as easily be the Bosch item from experiences I have seen.

My best mate has a full tilt turbocharged Holden rodeo V6 ( turbonetics Y2K) and it has had more than one bosch pump fail. And they were not by any means long in the tooth. He has now resorted to using 4 of them with allowance for two of them to die on a dyno pull/drag run and still be safe.

From what he,the builder and the tuner have diagnosed is that the bosch pumps, although being very capable of supplying fuel are very very susceptible to failure from any type of foreign matter that may pass through them which is what they have put the failures down to. Hence there are now filters before the pumps.

Not sure if it has any bearing at all in your situation but just thought I would add it as I have indeed seen bosch pumps fail early in there life. ( to Boschs credit, they were all replaced without question)

Cubes Grand Master

Cubes

Posted
  • Author
Posted

Thanks FatGTS-R.

The pump is what I would consider long in the tooth. Its around 4.5yrs old and as mentioned around 135,000km's old, well maybe closer to 145,000km's. :dry:

Tomorrow I'll ensure the turbo to afm pipe isn't split or leaking as I'm sure this could also do what I am experiencing.

rob82 Mentor

rob82

Posted
Posted

If your suss on the intank than I would fix it real quick as if it is not supplying pressure to the back of the bosch then you might be up for two pumps!!

And as for bosch pumps not liking foreign matter - no pumps like it, however I still believe the bosch will handle it better then most others.

Cubes Grand Master

Cubes

Posted
  • Author
Posted

Well this is going to be one of those niggly problems thats difficult to get to the bottom of.

I had a fiddle with it today and and its almost normal.

Idle is now fine but partial throttle cruise goes lean to the point where the o2 sensor can't pull it back in; slight throttle to accelerate the car has the o2 sensor flicking againl or with the feedback off has the sensor reading from 0-0.04v to the usual 0.9v.

I've disconnected the external pump and had the stock pump blowing through the disconnected external. The fuel pump appears to still be working fine as there was no difference with the external connected or not.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Murray_Calavera
      R33 GTR running -9 with no tune

      By Murray_Calavera · Posted

      I don't understand how this hasn't boiled down to - Upgrade the turbo when you have everything required. ECU, injectors, fuel pump, turbo, etc. Do it all at once.  If you don't have everything required, just enjoy the car as it is and keep saving up your pennies. 
    • Duncan
      R33 GTR running -9 with no tune

      By Duncan · Posted

      Sounds like you've got an interesting adventure ahead here with local support if you have trouble! My guess is that, unboosted, you will be OK with a small upgrade like -9. What will happen is that once the stock ECU sees more airflow than it expects it will add a heap of fuel and pull a heap of timing to be safe because it can't understand how it could get that much air without there being an issue. You will see clouds of black smoke and it won't pull hard through the midrange and top end. So, overall it will be a bit frustrating but should be OK. If you are still nervous set the base timing back 2o through the CAS, but it will be even more sluggish everywhere. As said above through...this is not my guarantee your engine won't be blown into a million pieces, leaving you looking for very hard to find parts A better idea is get a computer with logging ASAP, wire in a wide band O2 sensor and a use remote tuner. I've done multiple cars this way and while it is not as good as a specific tune on a dyno they can get it 90% right. I'd suggest if you can afford an R33 GTR these days you can afford an ECU and tune. And if you can't afford that you sure won't be able to afford the rebuild if it goes bad in the meantime,.  
    • Duncan
      New kid on the block

      By Duncan · Posted

      Yeah it would be nice if someone took the time to put that sort of information together, but there are a lot of variations in looms. I think you are making this way hard for yourself if you just want to get it running....sourcing an SR20 with the right wiring will be a billion times easier than matching the RB loom to an S15 chassis. If you do end up going this way, you just need to trace every wire in the loom with a multimeter, 95% of them will go to a location you can confirm at the ECU.....and then post it up for the next person who needs it  
    • Duncan
      Coolant leak?

      By Duncan · Posted

      Just top it up with water, and keep a general idea of how much you added. It is normal for water to be pushed into and pulled out of the reservoir through the cap, and it should not be more than half full or it will be likely to overflow when hot. Any decent mechanic can do a pressure test of the cooling system to confirm if you have a leak. Keep in mind if it is only leaking a little and when hot it may well evaporate before you see it hit the ground
    • GTSBoy
      Coolant leak?

      By GTSBoy · Posted

      I'd ask the shop what they used and use that. Mixing coolants is sometimes OK, sometimes not, and you have know the details of each coolant to know whether it's a good idea or not.
×
×
  • Create New...