Fuel Pressure, Lean mixture, pinging in Volvo 144 B20E

Dear All D-Jet experts. 
I have struggled for quite some time with a very lean mixture problem - lots of pinging from just a tad of throttle and lagging in rev-up. Based on all the wonderful input on this site I have tried to fix the issue my self - and now I need expert input please
But first - what have I ALREADY done to fix the issue;
- All Item numbers on the injection system checked and brought into conformance with original spec. Incl rebuilt fuelpump.
- Ignition - rebuilt original JFURX4 with contact free breaker - set at 10 deg BTDC without Vacc. it runs like a swiss clock 
- False air check with start-spray - no leaks
- Professionally Cleaned injectors installed
- Valve clearance adjusted to spec
- Cleaned fuel tank including new filters
- New fuel hoses and cleaned fuel lines
- Replaced the MAP sensor with another without change in condition
- New airfilter
- Cleaned and Adjusted Throttle switch
- Checked and cleaned all electrical connections to: MAP, Injectors, Temp sensors, Thermal time switch and fuel pump relay.
- Added a new 20mm2 ground cable direct on the intake manifold 
- Cleaned and closed the Damper valve on throttle clap.
- Checked AAV function
- New Valve cover vent hose installed
- New original Volvo B20E spark plugs 
- Runs only on 100 Octane fuel.

Still nothing changed - until I tried to squeeze the return fuel line with a pair of pliars - then suddenly the engine responded with a very healthy sound.
So I installed a Manometer and when I start cold - it shows 2.0 bars - after a few seconds it drops to 1,2 bar. I tried to increase the pressure on the Fuel Pressure regulator (I know Dr Djet strongly object to this indeed), but even if I screw it to the maximum setting, it would not go above 1,4 bar.
OK - so I bought a replacement - well it was "only" 120EUR used so I thought this was the final add to my endless list of fixes to get it running right. SAME #%#?!! result - and impossible to get over 1,6 bar even with the screw set at the maximum.

So - to the patient reader, here is the questions;
Could there perhaps be some old hardened fuel-residue stuck inside the FPR valve seat, and can it be cleaned out successfully with a chemical?
Is this a common issue, because the spring in the FPR gets weak over time, so adjustment becomes futile?
Can the membrane in the FPR not resist the modern Fuel with bio-alcohol additives so it leaks after some time?

Before I head out on the grey market and try another "Used & Tested" D-Jet FPR at a premium price - I would like to know if any other of you guys'n girls have solved a similar issue some other way?
Or - Is there an aftermarket alternative to the original, that is still on the market and that someone has successfully installed on a B20E engine?

Thank you for reading this - hope some one has time to nudge a fellow D-Jet owner, in the right direction with some good suggestions, BR Chris

 

Hi Chris,
at first you have to verify the pump gets enough fuel from the tank.

In most cases there are filters or similar devices inside the tank to prevent particles reaching the pump.
This could be clogged... by mud even old gasoline could have 'produced'.

No problem to find a new FPR that fits the car without any problems.
Here is one: www.ebay.de/itm/233812738789?_nkw=Webcon...tkp%3ABk9SR5b2yIC9ZA

www.ebay.de/itm/253916688146?_nkw=Malpas...tkp%3ABk9SR_Sk_4C9ZA
Regards
Norbert

Hi Chris,

welcome to Jetronic.org with your Volvo. I can assist your endless and expensive story with an ECU and a MAP sensor. But I am afraid that would only help my bank account not your engine.

Please put 12V on fuel pump to activate it and then disconnet return line after fuel pressure regulator and let this fuel run into a clean bucket.  It must be at least 750 cm³ / 30s  at a fuel pressure of 2 bar before pressure regulator. My suspicion is that it is too little delivery rate.

Dear Volker, thank you for your swift answer. When I replaced the unoriginal fuel pump with a original D-jet pump - I vented it through the cold start line and it delivered healthy amount of fuel. approx 1 dl in 4 sec. Plus - the fuel pressure peaks very high when I restrain the return line. So I would really like feedback on my questions about the old FPR´s, please. Some guy on youtube says that if the FPRs is left dry - they become leaky because the membrane dry out- is that true?
Thank you for taking the trouble with me - a true novice

Hi Chris,

sorry to disagree. When you measure delivery rate on CSV it is not against pressure regulator. It is speicified against 2.0 Bar pressure. That you can only measure behind pressure regulator.

Dear Volker, Got it now- the delivery volume must be from the return line
Will the pump be able to peak pressure up to 5 bar (because it can) when I restrain the return-line and still not be able to deliver the right volume?

Thank You Norbert.

I have - as I wrote above - cleaned the tank and replaced all filters, and I have isolated the problem to fuel pressure. The question is how remedy that issue

Hi Chris,

all you do is put a fuel hose on your pressure regulator exit to tank and measure the delivery rate into a bucket. But you shall see 2 bar in fuel line before regulator and engine shall not run. Just attach ground to pin 19 of ECU. It will trigger FPR (Fuel Pump Relay).

Hi Chris,

I was triggered by the rebuilt fuel pump.... Mayba a good idea to check the pressure direktly from the pump. I I am correct, should be approx 3 bar

kind regards 
Heinrich

Hi Heinrich

that is not good enough. Ultimately you need to know how much fuel is delivered against 2 bar pressure regulator. If that value is too low, you will see that pressure will drop during higher consumption.

Thank you Heinrich, when I restrain the outlet line from the Fuel pressure regulator with a pair of pliers the pressure rises immediately to above 4 bar, However I do not want to break anything - so I have not tried the max pressure, or if the internal over pressure relief valve in the fuel pump actually works.
Best regards Chris

Hi Volker,
got it however in case Chris got a pressure of 4 bar immediately, maybe a bit more, do you think it is the correct fuel pump for a D-jet system ? I have in mind approx. 3 bar and a bit in original configuration (for MB)
Anyway, then, must be something wrong with the pressure regulation valve...
Heinrich

Hello,
the pump must deliver a higher pressure than the working pressure.
Nobody inflates a tire that requires 2.5 bar with a compressor that delivers a maximum of 2.5 bar. There has to be a reserve.

A pump whose working pressure is 3 bar has to regulate down above 3 bar, for example at 5 bar. This is just for security-reasons, the FPR regulates in normal operation.
What you are observing and measuring is completely normal.

But the pump shouldn't deliver much more pressure - there are pumps that deliver 6 bar or even 8 bar, which is too much.
The L-Jetronic pumps designed for 3 bar are the best replacement because the D-Jetronic pumps are no longer available.

Regards
Norbert

Thank you Volker & Norbert. The pump is a Bosch 0580464007 - and to the best of my knowledge correct for the system in a Volvo. I have installed this pump recently - replacing an unoriginal pump because I thought that caused the pinging problem - but there are no change in the condition - that is why I believe the problem might located in the fuel pressure valve. BR Chris

What CR ?

Gone throught the pages
I see you cleaned the tank
I see the fault beginning from the pick-up in the tank till FPR.
in my case (Opel) I found a little filter mesh inside the fuel delivery tube was clogged.
blow air into the delivery line at the FPR up to the pump (tube removed)

Hi - i finally got around to measure the delivery rate from the return line. I have checked it both with a cold engine and a warm.
Cold it produces approx 700 ml/30 sec at 2 BarG
Warm it produces approx 750 ml/30 Sec at 1 BarG
The pressure drops once the engine gets Warm and that's where the pinging starts - It pulls and runs fantastic when it's cold and operates around the 2 BarG

Hi Chris,
I don't think the FPR causes the problem. Such a device isn't known for such a behaviour.
Some warming up cannot be the reason for the effect.

I think something in the fuel delivery line is the problem.
Mud sitting in a filter or strainer gets compressed by the flowing fuel,
the delivery line gets clogged more and more.

This is not related to the engine running, but to the fuel pump's running time and the amount of fuel running through the mud..

Try it out. Let the pump take the fuel directly out of a cannister.

Regards
Norbert

As fuel pressure drops with time, you should check electric consumption in cold condition and during warm-up, for example with a clamp ammeter. My point is that maybe a component in the electric harness of the fuel pump has its resistance that increase with time, so that fuel pump power decrease.


 

Hello Chris! 
Seems like a hard one to solve.
Wonder if you have checked the voltage at the fuel pump terminals exactly when fail occurs ?
Also a tip, the coolant temp sensor can short to gnd or give very faulty value when it is warmed up (even if ok at cold state), i have that experience. This can make engine run rough or even die. Exclude as failsource by putting in one resistor in the two-pin connector, simulating the temp of your engine (See manual for correct value on resistor)

Know that the last one is not related to dropping fuel pressure, but just saying.

Another tip is that the injectors and even cold start valve(leaking) may cause problem when engine hot. Have seen that. May be excluded as fal source by a plier, one and one hose blocking, monitor pressure gauge while blockin one and one hose.

Anyway, hope you and your volvo is ok

BR Terje
 

Dear All, thank you for valuable input - to help me solve the issue.
There has - finally - been time enough for some progress with the problem.
A lot of different things has been solved or remedied to better the problem. One thing I am sure off now - is that old Injection cars is not for impatient people
Problem one;
The fuel pump sound is a bit low toned buzz sound compared to what a fuel pump usually sound like, and it only primes for about ½ a second when the ignition is turned on before it stops again. A bit too short to actually get the engine to start so I have to prime it 4 times before it makes sense to turn the key to crank the engine. 
I have cleaned all fuel pump electrical supply lines and the main and fuel pump relay contacts with contact cleaner and that changed the sound of the pump - now it runs stable with a whizz sound instead. 
Problem two:
The manometer itself actually posed a problem, the damper fluid inside the instrument actually absorbs condensate while cooling down - and eventually fills the instrument completely. Result is counter pressure on the outside of the bourdon tube increasing with temperature - resulting in a lower reading when the engine was warm. The reading eventually went to zero with a running engine - which lead me to suspect the instrument. After releaving it of some of the damper fluid - the reading went up to 2 BarG rock solid regardless of temperature.

Pinging kept on - all airleak possibilities were searched out and found tight.
Problem three;
The ignition timing has been and still keeps being a mystery; The book says 10 deg BTDC with blocked vacuum line - but the engine sounds like a machinegun and bogs a lot on the slightest movement throttle at that position. And I've tried timing adjustments an endless number of times with very little luck, I have even switched distributors, and replaced the contacts with a breaker less solution, that helped a lot but did not solve the problem.
However the improved fuel pump performance actually showed a bit of sanity looking at timing again. Old school teaching - retard the timing to make the pinging disappear- the pinging finally changed from heavy to moderate reaching approx 0 deg. BTDC. But that was how far it was possible to turn the distributor body - because of the vacuum canister was touching the cylinder block at this position and the throttle response improved a bit too.
I finally reached to the conclusion that the distributor drive gear needed to be repositioned to allow for extra adjustment - it was turned one tooth clock wise (the rotor moves counter clock wise) and set back in - reassembled and adjusted a number of times iteratively to 8 deg ATDC - and whoof - pinging gone - but the car jerks and runs like it wants to be a kangaroo and the performance is poor - but the throttle response stopped bogging.
When I set it to approx 5 deg ATDC then it behaves fairly well and have a good throttle response but when it gets more than 2/3 throttle it pings slightly but nothing really bad. 
The question is now - is this "normal" and should this be accepted or have I just found a new problem?