Chasing a slightly lumpy idle...still

[AllHailKingVolvo]

Originally Posted by Laird Scooby

He almost certainly did then Phil! I can't remember exactly where it was on mine, it's about 6 years ago now and as i was crawling backwards on my back into the footwell (after removing the trim) with a torch i got confused over what was left and what was right.

If i was pushed to say where it was, i'd probably say between the clutch and brake pedals as a general area but bear in mind Volvo sometimes move these things on a whim and mine was the B230E so no fuel ECU, just the spark (EZK ECU) and i actually found it when i suddenly noticed this "spare" vacuum hose dangling in the breeze when i was bypassing the audio amp with a bypass loom from fleabay.

That said, mine had been running like a sack of spanners for a while at the time, rough idle, hesitancy/flat spot on acceleration, thirstier than it should have been and not as lively either. However, i put a lot of that down to a manky dizzy cap etc as i hadn't had it long at the time, scraped it through the MoT (emissions were the stumbling block - can't think why!) and like you are now doing, was working through its various problems.

Once i found the EZK unit and the stub (with no hose attached) i put 2 and 2 together and fitted the hose back on and on a road test later found it was the cause of the running problems.

As you can see, i wasn't trying to trace the rough running at the time but bypass the audio amp so i didn't pay as much attention as i maybe should have done.

If you have a spare door mirror glass or can "borrow" one of your wifes make-up compacts (preferably an empty one so that she doesn't moan you've left oily pawprints in her favourite foundation and also that same foundation doesn't end up pawprinted around the car!) and a torch, remove the underdash trim and save your neck, back etc by using the torch and mirror to find the EZK unit.

Hopefully this will be the final piece of your jigsaw puzzle, for now at least! You might also find you don't need to go to the expense of changing the fuel pumps yet too and save those for another time.

Excellent advice, thanks again Dave! I’ll get onto it this week. I’ve just got back from a 4hr round trip in it and it didn’t miss a beat bar the issue we’ve been collectively chasing, drove very well indeed in general!

I’ve been running it this week on firstly a tank of BP Advance and then a tank of Shell V-Power. It seemed initially that the Advance made the idle/hesitation a little worse, but I’m not sure what that indicates/doesn’t indicate.

[Laird Scooby]

Originally Posted by AllHailKingVolvo

I’ve been running it this week on firstly a tank of BP Advance and then a tank of Shell V-Power. It seemed initially that the Advance made the idle/hesitation a little worse, but I’m not sure what that indicates/doesn’t indicate.

Probably clearing out whatever was last used i would think Phil - not familiar with BP Advance, is that the normal 95 RON unleaded from BP?

My redblocks always ran best on BP Ultimate and strangely, the B280E/PRV engine it's a toss-up between BP Ultimate and Shell V-Power Nitro - both being the high octane versions.

None of my cars like Esso (or Tescos - strange you now get Clubcard points on Esso fuel - very little help!) but the Rover 827 prefers BP Ultimate as well.
The bonus for me with that is BP supply Sainsburys (hence Nectar points on Sainsburys fuel) and the strangest of all, recently the B280 760 i've got now has "gone off" Shell V-Power Nitro, preferring a diet of Sainsburys/BP Ultimate.

Anyway - i digress - maybe now it's your weekend you'll have a chance to have a look for the ignition advance vacuum hose that feeds the EZK unit and make sure it's connected - would be great if that is the problem!

One other thought i had - is yours K-Jetronic or L/LH-Jetronic Phil? I@m sure you've posted photos of the MAF so i'm going with LK-Jetronic but the brain cell is having a funny five minutes!
I know on the B230E i had last, the injector "O" rings were Jacobs'd and were leaking which caused a randomly rough idle. The two sets (top and bottom) came out about £18 from Volvo, if yours is K-Jet it might worth checking those. Likewise with the bottom "O" rings on the injectors if it's LH-Jet, just to be on the safe side.

[TonyS9]

Well I got the B230FT in the 360 running again after an upgraded cam (going from T to A) and new adjustable pressure regulator. It is even more lumpy now, but I didn't check the valve clearances, which apparently I should have done. From memory the 360 it came out of was quite lumpy / missy aswell on idle (and not running any O2 sensor so probably on the rich side).

[TonyS9]

Also interesting on the vacuum load input on the older EZK ignition, the LH2.4 (+EZK) uses air flow as the load signal (ultimately slower response though sadly). This is read by the LH fuel computer and communicated to the EZK.

[Laird Scooby]

Originally Posted by TonyS9

Also interesting on the vacuum load input on the older EZK ignition, the LH2.4 (+EZK) uses air flow as the load signal (ultimately slower response though sadly). This is read by the LH fuel computer and communicated to the EZK.

Handy to know Tony, thanks! I wondered why it didn't appear to have a separate vacuum feed on mine (LH2.2) for the ignition, i subconsciously assumed that the LH ECU communicated something to the EZK unit, in the same way as the PGM-Fi system does on my Rover, albeit with a MAP sensor on that instead.

That means if Phil can't find a stub on the EZK or a hose to feed it, his is slightly more modern than i think it is.

[AllHailKingVolvo]

No stub or hose in sight on my EZK alas, it's the B200F which has the MAF and the LH 2.4 Jetronic system...the plot thickens!

Could it be the MAF or an injector not firing properly?

[Laird Scooby]

Originally Posted by Laird Scooby

I know on the B230E i had last, the injector "O" rings were Jacobs'd and were leaking which caused a randomly rough idle. The two sets (top and bottom) came out about £18 from Volvo, if yours is K-Jet it might worth checking those. Likewise with the bottom "O" rings on the injectors if it's LH-Jet, just to be on the safe side.

Originally Posted by AllHailKingVolvo

No stub or hose in sight on my EZK alas, it's the B200F which has the MAF and the LH 2.4 Jetronic system...the plot thickens!

Could it be the MAF or an injector not firing properly?

I'd have a look at the bottom injector "O" rings Phil, as far as i'm aware the LH-2.2 doesn't have a Lambda and the LH-2.4 does but the systems are very similar otherwise.

Sounds daft but have you checked the inlet manifold nuts/bolts for tightness? I was just thinking about squirting some WD40 or Eezi-Start round the injector bottom seals with the engine idling to see if anything altered and it crossed my mind that it's not unknown for the inlet manifold gaskets to go weak, or simply be just plain loose.

[AllHailKingVolvo]

Originally Posted by Laird Scooby

I'd have a look at the bottom injector "O" rings Phil, as far as i'm aware the LH-2.2 doesn't have a Lambda and the LH-2.4 does but the systems are very similar otherwise.

Sounds daft but have you checked the inlet manifold nuts/bolts for tightness? I was just thinking about squirting some WD40 or Eezi-Start round the injector bottom seals with the engine idling to see if anything altered and it crossed my mind that it's not unknown for the inlet manifold gaskets to go weak, or simply be just plain loose.

I’ll torque up the manifold bolts, that’s a good point and one I hadn’t thought of before!

Another thing I’ve noticed, the car has a modern stereo head unit, but the aerial is missing from the car so the radio itself doesn’t work. However, when I plug my phone/iPad into the aux input, I can play mp3s or streamed music. This is no problem, but when I plug a car charger into the cigarette lighter and connect it to my phone whilst it’s connected to the stereo, there is loud and insistent electrical interference introduced into the signal.

Could the radio suppression relay be faulty? If so, would this introduce electrical “noise” into the system and cause embuggerance with ECU/EZK ignition/timing/fueling maps?

[Laird Scooby]

Originally Posted by AllHailKingVolvo

I’ll torque up the manifold bolts, that’s a good point and one I hadn’t thought of before!

Another thing I’ve noticed, the car has a modern stereo head unit, but the aerial is missing from the car so the radio itself doesn’t work. However, when I plug my phone/iPad into the aux input, I can play mp3s or streamed music. This is no problem, but when I plug a car charger into the cigarette lighter and connect it to my phone whilst it’s connected to the stereo, there is loud and insistent electrical interference introduced into the signal.

Could the radio suppression relay be faulty? If so, would this introduce electrical “noise” into the system and cause embuggerance with ECU/EZK ignition/timing/fueling maps?

Thing is Phil, you've come a long way on getting this car running right, it could be now that you're chasing rainbows and that's as good as it'll get, ever or it could be there is something silly that's not common and has been overlooked.
Is there a chance you can take a video of it idling and upload the video? About 30 seconds should do it, just so we can all hear what it sounds like.

As for the interference when using the charger on your phone, have you tried a different charger and is it a genuine one for your phone or a Chinese thing for 99p off ebay?

The sole function of the RSR is to provide a feed for the injectors, Volvo in their wisdom found it reduced radio interference from the injectors when running. As such i doubt very much if it's related to the interference you get on your music when using a charger on your phone. First thought would be the charger, hence the questions above!

I get what you're saying about something causing interference to the ignition map, it could be a faulty or loose knock sensor, they're not meant to be that tight but if memory serves correctly, should have threadlock on the securing bolt thread tp prevent the bolt coming loose. Might be worth checking, fairly sure they're a piezo-electric device so unplugging it should provide a simple go/no-go test (although it may put the ignition map into default minimum advance) to see if it is causing the occasional timing malfunction.

I'm hoping you know where it is which would save me breaking the bad news that it's under the inlet manifold, roughly speaking between #2 and #3 inlet tracts.

[AllHailKingVolvo]

You could be right about it being as good as it gets. Something feels a bit amiss but there has to be a limit when it comes to “firing the parts cannon” at the car!

I’ll check the knock sensor and see how it all looks. The Bosch units are cheap enough so I may replace it just to be sure.

The charger is a Halfords unit which was about £15 as I recall...it’s the only one I could find that was long and slim enough to fit the deep cigarette lighter socket in 7/900s!