Rough running

Rough running

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Discussion

BlueWedgy

Original Poster:

382 posts

102 months

Sunday 11th February
quotequote all
As the title really.

I lay the car up in the winter months, but do try to start it on a regular basis.

Recently 350i has started to run rough from the odd bank of cylinders and smoke fairly bad, smelling of very strong exhaust fumes.

I have checked the compression engine cold, all cylinders are within 10% of each other.
Spark all round and strong.
New spark plugs.
The injector plugs seem to fire an LED ok.

I am wondering if the E fuel has made an ejector go bad, or just a bad injector or 2 in general.
Or is it possible the head gasket could have gone, I understand that this side had some head work previously some years ago, due to a hose coming adrift and overheating.

Just my luck It always seems to be the hard-to-access side of the engine that has issues.

Does anyone have any spare injectors?

Regards

350zwelgje

1,820 posts

261 months

Monday 12th February
quotequote all
Had something that looked like it, was the coolant temperature sensor.
Myself do a check to eliminate this sensor with a paperclip in the connector (shortcut it) to simulate the engine is hot and if running right....., will replace it.
You can use a resistor, but for a test shortcutting it is will do.

Rob

BlueWedgy

Original Poster:

382 posts

102 months

Monday 12th February
quotequote all
Hi Rob, yes will check that when I run it up next ta. It did have a resistor in about 3 years ago. When I checked it then it was working per the specs, so I deleted it and it ran well until recently.

Cheers

adam quantrill

11,538 posts

242 months

Tuesday 13th February
quotequote all
Agreed - CTS is first stop.

BlueWedgy

Original Poster:

382 posts

102 months

Thursday 15th February
quotequote all
Hi Adam / Rob,

I bridged the connector with a 200ish ohm resistor, which did make a small amount of difference, to the smoke, but the misfire still seems to be there. I did not run the car for long, as it was late evening as you know these things are not of the silent type wink.

I measured the current CTS in situ when cold and it read around 3200 ohms, there was a change in resistance for the time I ran the car, down to 1300 ohms, but I did not run it to full warmth at this point, so not sure if it will run all the way down to warm idle resistance reading. I see no reason why not though.
Adam, I assume from this very old thread that the sensor mentioned (and shown in the Wedge Part Numbers) is the correct type? I can buy one of these for not a lot, so will just go and get one in any case I think.

https://www.pistonheads.com/gassing/topic.asp?h=0&...



Still heading towards a sticky or broken Injector


I have based my initial reading off of this.


Cheers Ray

adam quantrill

11,538 posts

242 months

Friday 16th February
quotequote all
"They are very easy to test just stick an ohmmeter across the two terminals and you should see 300 ohms +/- 100 when cold. That's what you need for starting."

So there you are.

Bridge it with a papecrlip or bit of wire.

Wedg1e

26,804 posts

265 months

Wednesday 28th February
quotequote all
It could be ye olde solder issues with the ECU, try clonking it with a screwdriver handle while idling and see if the sound of the engine alters.

BlueWedgy

Original Poster:

382 posts

102 months

Sunday 7th April
quotequote all
I came across this.

https://robisonservice.blogspot.com/2014/02/blown-...

Is this a common fault of the Rover engine?
I am almost at a point of stripping the head off. I know from the previous owner that this head had an issue after a hose blew.
Being the head under the Plenum I know that it is going to be a mission, my enthusiasm for this car is not at it's highest, I am spending more time with it apart than driving it, which is kinda defeating the point of having it.

I do want to look at the cam, but that's another mission should it be toast.
I also have a tappety sound so was looking at replacing the bank of lifters, if the cam proves OK.

Sounds like I have convinced myself to dive in.....argue

mark387mw

2,179 posts

267 months

Sunday 7th April
quotequote all
As Wedg1e says, check the ECU.
I had the same problem and a resolder fixed the issue.

BlueWedgy

Original Poster:

382 posts

102 months

Sunday 7th April
quotequote all
The ECU is working fine, The injectors are firing, I can hear them and used an LED to check. it is a single cylinder misfire not a whole bank, as the ECU fires all even and all odd. The spark plugs are new and I have a lead tester, so electrically all is good.
It seems to be the second cylinder in from the bulkhead on the passenger side. The manifold feels cool on that cylinder.

I re-flowed the ECU a few years back when the same bank stopped working this cured the problem, at that point.

With a full bank out the car will hardly drive, currently, it will drive, but there is definitely a missing cylinder?

KKson

3,403 posts

125 months

Sunday 7th April
quotequote all
Could be camshaft. When I bought my project 390SE it had been under investigation for two years with a misfire. Scott who owned it before me had spent a small fortune investigating and swapping components, including a rebuilt ECU. Found that the exhaust lobe on no 1 cylinder was absent, as in so worn there was no evidence at all of a lobe!! New V8 Development's Stealth camshaft and all was good

BlueWedgy

Original Poster:

382 posts

102 months

Sunday 7th April
quotequote all
Thanks Keith, time to get the spanners out again and jump in with both feet me thinks. wobble

Wedg1e

26,804 posts

265 months

Sunday 7th April
quotequote all
It could be a cam follower not pumping up (hence the tappetty noise) - but they're usually pretty reliable.

Edit: hmm, compression readings would tend to rule out cracked head, bent valve, head gasket.

I have a number of spare injectors, but you can test them yourself with a length of hose and a jam jar.

Some versions of the Jag V12 used the same injectors, you can pick up an entire rail of them for not much.




Edited by Wedg1e on Sunday 7th April 14:20

Wedg1e

26,804 posts

265 months

Sunday 7th April
quotequote all
BlueWedgy said:
With a full bank out the car will hardly drive, currently, it will drive, but there is definitely a missing cylinder?
My ECU infamously decided to play billy suggers on the way to a Wedgefest, a 400 mile round trip for me. Effectively the car would only seem to pull cleanly at full throttle (officer whistle), everywhere else it ran like Oscar Pistorius on a shingle beach.
By the time I hit Ferrybridge services (about 93 miles) it had used most of a tank of fuel, so I unplugged two injectors on each bank and it made it down to Stratford, although it sounded like a Subaru Impreza.

BlueWedgy

Original Poster:

382 posts

102 months

Sunday 7th April
quotequote all
Thanks for the reply. I just removed the plenum and rocker cover, (both very clean inside) to see if rocker arm moves the valves. I figured if the cam was shot then there would be little or no movement, I will stick a dti on to see if the movement is consistent across inlet and exhaust, maybe tomorrow night.

I was going to look at the injectors thanks for mentioning it. I will try to test them, I may also swap for the other side as they appear to be working, that gives me easier access if any are down or need replacing.
I was wondering what the injectors are, I did start to look at it, but being a bit accident-prone of late injuries (self-inflicted) keep getting in the way of doing things.

Wedg1e

26,804 posts

265 months

Sunday 7th April
quotequote all
BlueWedgy said:
Thanks for the reply. I just removed the plenum and rocker cover, (both very clean inside) to see if rocker arm moves the valves. I figured if the cam was shot then there would be little or no movement, I will stick a dti on to see if the movement is consistent across inlet and exhaust, maybe tomorrow night.

I was going to look at the injectors thanks for mentioning it. I will try to test them, I may also swap for the other side as they appear to be working, that gives me easier access if any are down or need replacing.
I was wondering what the injectors are, I did start to look at it, but being a bit accident-prone of late injuries (self-inflicted) keep getting in the way of doing things.
Other way around, I'd have thought: if there's no lobe left on the cam the rocker arm will be slacker than an ex-wife.

From memory, the injectors are Bosch 0 280 150 105, but I'd need to dig out a dusty old tome to verify. They were used on lots of cars where the per-cylinder capacity is about the same as the RV8.
They're something like 193cc/min, again this is poking grey matter that hasn't been disturbed in a while (some stuff seems less important these days).
They have a short hose stub crimped on and are then Jubilee-clipped to the fuel rail; if you extract one you can extend the hose by suitable means. Link out the pump relay or stick a cloth in the airflow meter to hold the flap open. Pull all the other injector plugs off, point the injector into a jam jar, turn ignition on and repeatedly flick the throttle linkage open. You can check spray pattern, no dribbles and the volume against other injectors.

I like to put a pressure gauge in the hose stub for the cold start injector; prime the rail and turn the pump off. You should get about 3 Bar and it should hold around that point for - well, the longer the better, but if it's only seconds you probably have a duff pressure reg or a leaky injector.

I run later-type injectors that are meant to plug-in to a a fuel rail with an O-ring; if you cut the upper plastic stub off there's a steel insert you can clamp fuel hose to. I forget the type but they're something like 220cc/min which means you can drop the rail pressure to get the same running, then a rising-rate regulator gives you plenty of scope for boost whistle

Edited by Wedg1e on Sunday 7th April 18:20

BlueWedgy

Original Poster:

382 posts

102 months

Monday 8th April
quotequote all
The injectors seem to work OK, pulsing with a switch good looking spray pattern. So another evening, to look at the cam and rockers pushing down the valves. I am a fair way in, looking like it's heading towards head off, to see if anything untoward is lurking unseen?

BlueWedgy

Original Poster:

382 posts

102 months

Wednesday 10th April
quotequote all
Been out this evening, pulling more bits off the engine.

I pulled the passenger rocker cover off a couple of nights back. Now both the rocker covers are off, along with lots of other bits, here's the strange thing. The side that I thought the problem was (the Passenger side bank) shows only clean oil around the rocker shaft and rockers. The drivers side however shows signs of water droplets on around the rocker shafts and rockers.

If there is a problem with water I would expect it to show on both banks.
Am I missing something obvious here?

Cheers

Wedg1e

26,804 posts

265 months

Wednesday 10th April
quotequote all
You'd imagine that if it was just condensation you'd have it on both sides... if it's being sprayed from somewhere that would sound like a crack through to the water jacket. Wouldn't necessarily explain the rough running.
Does it taste of antifreeze?

Do you have access to one of those flexi video inspection cameras? I'm thinking poke one into each bore via the plug holes and look for signs of steam cleaning on the piston crowns.

You don't mention the rocker arms, any sign of excessive travel? Thinking about it, if you had a lifter refusing to pump up there's a chance the pushrod would disengage from the rocker arm anyway, which would be easy to spot.

Edited by Wedg1e on Wednesday 10th April 22:56

BlueWedgy

Original Poster:

382 posts

102 months

Thursday 11th April
quotequote all
Thanks for the input.
My initial thought was condensation, as I run it at idle during the winter regularly, and tax for the summer (I do say summer loosely) months for use. So yes would expect condensation to be showing in both sides, unless the breather is allowing in moist air? The breather was cleaned about a year and half ago, at the time the cannister showed no signs of water.
I did notice that the bottom of the Plenun at the butterfly end, underneath was damp and shows signs of being poorly filled with some kind of resin. The Plenun is also linked to the rocker breather by way of a pipe, so could have been drawing in cold damp air?

However I haven't looked into the cylinder, I do have a borescope, but I am so far in now that I will probably just remove the heads in any case, as I want to check the hydraulic lifters. If the piston was washed clean, I would expect the spark plug to be the same. I must say that the oil off the dipstick, to me does smell a little fuel-like, as though a cylinder has washed down.
As with all things re-assembly is a bit of an unknown as I think the heads have been skimmed, so head gasket size may be an issue, I will have to measure the deck height (when I find a standard spec measurement) to see how much material has been removed. Standard top-end gasket sets are very cheap, but I assume a standard tin gasket is a no-go after headwork.

The cam seems to be doing cam things on both sides, so seems there are still lobes on that, at least that is one bonus.
I am still a little concerned that the block may be toast? Hiding some form of hidden water jacket crack.

As mentioned enthusiasm is at an all-time low for this car, so work is in the evenings and very sporadic at best. I have worked on lots of 4 pot cars, but not so V8's, However last winter I did replace all lower bearings and clutch with the engine in the car, that was a mission, all seemed good when looking up from underneath.
With hindsight, it would have been easier to have taken the whole engine out, but things seem to happen at a later date causing more work.