I said i'll be back!

[Laird Scooby]

Have you no longer got yours Andy?

[AndysR]

Yes, sold it about a month ago, hadn’t used it for 5 months due to getting a new Volvo, didn’t have the room to store it and as it was sat outside didn’t want it deteriorating. Off to someone who’ll hopefully get some good use from it.

[Laird Scooby]

That's a shame Andy - do you regret selling it?

[Laird Scooby]

Well it's been a long time since the last update! Not a lot has happened, been a case of feeding the beast and driving!

However, a couple of points to note, following last years MoT fail due to a leaky fuel tank sender/pump unit seal being past its sell-by date, i renewed that. Also renewed the HT leads with a set from Rock Auto including the rpm sensor on #1 lead for about £30 delivered. Just in the nick of time as well, #3 lead had broken "invisibly" inside the boot that goes over the plug between the lead itself and the connector.

This had resulted in a "half misfire", most obvious when it was cold. New leads fitted, nice and smooth from cold with better starting all round with slightly improved performance/smoothness overall.

Until recently. Occasionally it would be a pig to start from cold. Knowing a few diagnostic tricks to prove certain things, not only did i always get it started but narrowed the fault down to the fuel pump relay.

Felt energetic and enthusiastic today, plus i got to the point where i was fed up with it playing silly burgers when it shouldn't!

As such, i pulled the fuel pump relay out. Not an original Volvo unit but i opened it up and found this :



Those three small round pads more or less across a horizontal (imaginary) line show some of the trouble. You can just see the cracks in the solder ring around each wire/component leg. On the next pic, you can see some of the larger pads also have similar cracks in the solder :



The three small pads are the signal connections from the ECU telling the relays to close and power up the fuel pumps. The large pads are the power connections, one in and two out for the in-tank pump and underbody pump.

When i first pulled the relay, i tried starting the car to firstly prove it wouldn't start without it and secondly, to empty the pressure in the fuel rail - important for checking later.



That's where the relays are on the 760, the orange screw on the bottom right holds them whole board in place.



It's also located by this tongue and slot :



Tongue more or less centre and slot engaged, can also be seen a couple of pics up where the relay board is completely out.

After soldering, cleaning and lacquering, i refitted the relay into its box and then back in the car.


Soldered!


Cleaned!


Lacquered!


Ready to refit!

Turning the key to the second position (ignition on, not trying to start) for a couple of seconds to allow the pumps to prime the system then turning to the start position, the engine fired straightaway. This means the priming function now works again and so does the main function. The main function always did work, although looking at the solder joints as they were, i don't know how much longer it would have done!

This proved useful in other ways too. I recently bought an aftermarket cruise control kit to fit and needed somewhere to mount and earth it. That earth bracket behind the relay board is ideal, it serves both functions! More to come later on that, when i figure out exactly how to connect the Bowden cable to the throttle - got the other stuff worked out, just that final hurdle!

[Laird Scooby]

While doing some other general stuff, i recently noticed my air filter was as black as the ace of spades adn having found a nice BOGOF deal on ebay for £4.99 delivered per filter and get the second free if you order both at the same time, i bought 4 and fitted one - the rest are in my stash ready and waiting!

However, i've also been experiencing a strange fault recently. Strong smell of petrol when i open the car, pig to start, runs rough as a badgers behind, eventually clears but is generally a bit "lack-lustre". Suspecting the injectors, i added some Redex when i fueled up which seemed to improve matters - somewhat!

While changing the air filter, i noticed a strong smell of BP Ultimate coming out of the air inlet trunking to the throttle body. Shouldn't happen!

As such i came to the conclusion the injectors were well past their sell-by date, or given the pong, smell-by date!

On another thread, Phil (AllHailKingVolvo) reminded me of an upgrade popular on the early Jeep Cherokees which involved replacing the single pintle injectors with more modern 4-pintle injectors from a Dodge/Chrysler Neon.

After a bit more investigation and circumstantial (but strong) evidence, i decided to take the plunge and hunted for a set of six 0 280 156 045 injectors that among others, are fitted to the later 960 and a whole plethora of other cars.

The set i found first, at a very good price was from an Omega 3.2 V6 so i put in a Best Offer and a few days later, they landed.

Here's the story on them :


Firstly, big thanks to Phil for reminding me of this upgrade and secondly, for giving me the inspiration to do it on mine! Finally got round to doing it today, after the injectors landed the other day :



Just to get a "base" figure, i went out the other day armed with my trusty Gunsons Gasteseter and took a reading at idle - i was expecting (hoping for!) 1%CO at idle as that's what i'd previously set it at last year just before the MoT.



It showed 0.9%CO which could well be down to the nice new, clean, air filter! Then, for no apparent reason, it shot up to 2.6% and started running like a hatful of monkeys a***holes :



In other words, how it's sometimes been running lately and stenching of petrol at the same time - if i've left the car alone for a while, it's been a pig to start (hot or cold) after that, especially if it stinks of fuel when i get in.

When i was doing the air filter i kept getting a whiff of BP Ultimate from the inlet trunking and to be honest, that was the final piece of the jigsaw for me. Told me one or more injectors are leaking when they shouldn't be - the high CO reading simply confirmed that!

Here's a close up of the squirty end of the new injectors - note the 4 spots - those are the pintles that inject the fuel. Only one on the old ones.





Third injector from the left, the pintle is partly withdrawn as if injecting - should be out! Proof positive my theory was correct!

Anyway, back to the actual job of replacing them!

First, i popped off the clips from the injectors, noticing that injectors 2, 3 and 4 were a bit tighter than the other three. More of this later!




One bank of injectors disconnected ^^^^^ and the other bank :



Right hand bank fuel rail unbolted from the inlet manifold :



Left bank and FPR unbolted :



New injectors ready to go in after giving the "O" rings a vital bit of lube to help them "slip in nicely" - oooooo-errrrrr missus!



Right bank of new injectors in place :



Left bank looked the same from the other side!

All bolts etc replaced (except one i dropped, it might surface one day unexpectedly but not a problem for now) and i decided that seeing as the new injectors had the grooves for the clips, i would fit them anyway - "belt & braces" so to speak.

Fired up and it coughed and spluttered a bit until the fuel rail had fully pressurised then it ran perfectly on all..................... errrrr............ five!

The problem was #3 injector - i hadn't quite pushed the injector connector plug fully home! Pushed it fully on, the click i heard previously thinking the wire clip was going over the lugs was in fact the wire clip popping off the lugs! D'oh!

Anyway, fired it up again and it ran nice and smooth on all 6, still slightly hesitant at first which i'm fairly sure was down to the injectors probably being a bit dry, then it smoothed out to smoother than it had been on the old injectors.

The "proper" test drive came at walkies time. At first, it didn't seem that different then i pulled out of the cul-de-sac i live in and tickled the loud pedal how i normally would to get to the next junction. I don't usually have to brake for that junction, just ease up on the loud pedal - 'nuff said!

Being a bit more gentle, at least until i had room to be a bit more adventurous without speed humps, potholes and pedestrians getting in the way, i noticed it was much smoother and i now had throttle response - instantly!
Before it always responded but was a case of sending the engine a polite request by carrier pigeon and hoping! Now it's much more "now if not sooner".

Generally speaking it's much smoother and i can make better progress at lighter throttle openings. The most impressive bit is what i've decided to call the "wall of torque".
Being a 90 degree V6, it always was a torquey unit but now it feels like all the torque is available at much lower engine speeds. It feels like no matter what or when, firstly it responds instantly and secondly, it's much livelier because of the better torque delivery.

This should (eventually) translate into better fuel economy, for now that "wall of torque" is incredibly addictive!

For those that are wondering, mine hasn't taken time to re-learn fuel trims etc because it has no Lambda sensor, no cat and no feedback system - all the improvement is simply down to the injectors!

I will check and if necessary adjust the CO in a few days time once the injectors have bedded in a bit. Next job on the agenda is the valve clearances, it's sounding a wee bit tappety!

Then the LPG conversion and get the A/C going again but those are for other threads!

[Stephen Edwin]

It is great that your jam jar is running well.

It would be interesting to compare the result if new Volvo spec injectors were installed. The previous injectors were aged and one sounds as if it was faulty.

Is there a mileage time recommendation from Volvo for replacing injectors in their various engines?

[Laird Scooby]

Originally Posted by Stephen Edwin

It is great that your jam jar is running well.

It would be interesting to compare the result if new Volvo spec injectors were installed. The previous injectors were aged and one sounds as if it was faulty.

Is there a mileage time recommendation from Volvo for replacing injectors in their various engines?

Hmmmm, interesting concept, new "Volvo spec" injectors.

That's what i fitted!

Except they were used by a V6 Omega in between whiles!

The thing is, Bosch no loner make the original, single pintle injectors as fitted to my beast when it was new, 30 years ago. What they make instead, and recommend as the updated version, are what i fitted.

The old injectors were definitely aged and one was almost certainly faulty - in fact it looks faulty in the photo!
In theory, two things can cause an injector to become "dead". One is a burned out coil, second is a worn out pintle. It would appear they are all worn and one pintle is sticking in at times, causing a permanent leak of fuel into the inlet manifold.

It would almost certainly be possible to have these cleaned/refurbished but at £15 + VAT per injector plus P&P that's £108 + P&P - these were well under half that so very cost-effective in that respect.

Also because it's a 4-pintle design, they apparently atomise the fuel more efficiently which is probably the reason for the improved torque and throttle response and should improve economy eventually.

The same injectors are also used on the later 960s and if you have a B200F in your 240, would be the same for that as well.

[Stephen Edwin]

Ah now that is clearer. You have fitted second hand items identical or equivalent in specification to what Volvo would currently specify?

And.

Is there a Volvo recommended time mileage recommendation to change the injectors for various engines?

[Laird Scooby]

Originally Posted by Stephen Edwin

Ah now that is clearer. You have fitted second hand items identical or equivalent in specification to what Volvo would currently specify?

And.

Is there a Volvo recommended time mileage recommendation to change the injectors for various engines?

Secondhand items equivalent to what Bosch specify as the replacement for the original injectors fitted. Volvo would currently specify the same or an equivalent Bosch number, the OE fit isn't limited to a single Bosch part number, they made several injectors with similar characteristics, flow @ 3bar and electrical properties so any one of those "different" injectors might have been fitted originally.

To the best of my knowledge, there isn't a time/mileage period for renewing injectors as a matter of course, usually they are only renewed/replaced when a fault arises.
I could as said above, have had the old injectors cleaned/refurbished but in terms of cost, these were cheaper, they're newer and a more fuel-efficient design.

[Stephen Edwin]

This will be academic for me unless a need arises. I am, interested, a little.

There has been reference to yellow injectors. I suspect that might be the Bosch injector offered by parts suppliers for my B200F. And as you say that would be the same for your car. Possibly the part Volvo would specify/supply now. Or would you say Volvo parts supply what you have fitted? Oh well it doesn't matter.

I see your arithmetic. Re furbishing the old injectors costs about the same as buying an entire new injector. And you got a good deal on a set of six secondhand. Cushti.

It would be interesting if the injectors were available, to compare a set of good condition single squirt to a set of good condition four squirt, in the same car. But at these costs who can realistically afford that?