240 General: Mysterious Starting/running Problems

[leftfootleashed]

This bank holiday weekend business seems like a good opportunity to sorting out some niggling problems I've had for a while with my '89 240 GL, B200E.

It may be more than one problem, or they may all be related, but basically:
- It takes ages (up to a minute of cranking) to start when it's been sat for more than a few days. The battery's coping with this so it's not that. It always starts eventually, and once its warmed up starts no problem.
- Immediately after starting, it runs at very low revs (~500rpm) until it warms up a bit. After a run, when it's fully warmed up, it runs too high (I think) - >1500rpm.
- When idling, it sounds what I think is described as "lumpy", as if it's regularly missing every second or so. The guy in the garage commented on it when doing the MOT, but couldn't say what it was.

(Just to increase the mystery, the second problem appeared after I changed the injector seals a couple of months ago. Before that, it started fine, immediately ran up to about 2000-1500rpm, then gradually came down (i.e. the opposite problem to now). After doing the seals, I had to adjust the idle speed to get it to start and run at a reasonable speed.)

OK, anyone got any suggestions?

Cheers,
Dave

PS Any reason my engine isn't in the list of prefixs for the thread title?

[heckflosse]

Originally Posted by leftfootleashed

This bank holiday weekend business seems like a good opportunity to sorting out some niggling problems I've had for a while with my '89 240 GL, B200E.

It may be more than one problem, or they may all be related, but basically:
- It takes ages (up to a minute of cranking) to start when it's been sat for more than a few days. The battery's coping with this so it's not that. It always starts eventually, and once its warmed up starts no problem.
- Immediately after starting, it runs at very low revs (~500rpm) until it warms up a bit. After a run, when it's fully warmed up, it runs too high (I think) - >1500rpm.
- When idling, it sounds what I think is described as "lumpy", as if it's regularly missing every second or so. The guy in the garage commented on it when doing the MOT, but couldn't say what it was.

(Just to increase the mystery, the second problem appeared after I changed the injector seals a couple of months ago. Before that, it started fine, immediately ran up to about 2000-1500rpm, then gradually came down (i.e. the opposite problem to now). After doing the seals, I had to adjust the idle speed to get it to start and run at a reasonable speed.)

OK, anyone got any suggestions?

Cheers,
Dave

PS Any reason my engine isn't in the list of prefixs for the thread title?

Hi,
Assuming all the usual suspects like leads, inlet and head gaskets are good, it sounds like a possible fuel pressure problem?
there is a fault tracing section in the volvo manual for all this,if I remember correctly it involves removing all 4 injectors and lifting the airflow plate/plunger to see if they all spray equally into a measured container.
best of luck, check the easy things first though!
James.

[leftfootleashed]

Hi James,
I assume by leads you mean the ignition leads? This is one of the few service items I haven't replaced since I bought the car so I don't know when they were last done - is it worth trying them?
Gaskets are good as far as I know, have tried spraying carb cleaner around inlet manifold when running to check for leaks, and no water appearing in oil.
Do you happen to know where the airflow plate/plunger is?
Cheers,
Dave

[Paul240480]

The air flow plate (venturi ) is below the rubber belows under the inlet manifold.
Held in place by two large jubillee clips. It has an arrow on it to show its correct position for refiting.
.
Follow this link: http://www.volvoforums.org.uk/showthread.php?t=121331

Which , if blocked may well be the problem

[leftfootleashed]

Hi Paul,
Thanks for the link and the excellent write-up. I cleaned the flame trap out a couple of months ago, but I'd not heard then about the advice to remove it. I've done that now (mine looks a bit different to yours, see left item in photo) and also cleaned both fat and thin tubes, and the venturi, bowl and inside of the bellows with carb cleaner.

In the fat tube and the flame trap holder there was a bit of white "mayonnaise" of the sort that under the oil filler cap I would say indicated head gasket failure. What might that indicate and should I be worried about it?

Everything else was a bit oily but generally clean, definitely nothing blocked.

However, the thin hose came off the brass intake manifold connector when I pulled the other end off, and I later realised it had split from the end (probably when it came off, though it could have been like that for some time since I didn't actually see it split) - see middle item in photo. Since it was only an inch and it looks like there's enough tube to reach until I can replace it (know the dimensions?), I cut the end off. When I tried to put it back on the connector, I realised it wasn't wide enough because there was some sort of rubber cap (right item in photo) on the connector, apparently blocking it off. What do you make of this?

Cheers,
Dave

[Magnumpi]

Your description is exactly what my car is doing. I've yet to get to the bottom of it, after changing all ignition components, both fuel filters, both injector seals and cleaning the venturi (although it wasn't really dirty).

I've recently purchased a compression tester (foolishly from the market) got it home to test and it gives no reading, but not due to there being 0-compression, just the fact it's a Mickey Mouse tool!

I also adjusted the mixture and got it running to a standard that was nice and useable. However after 3 days of being fine it started playing up again.

Could it be some sort of intermitent electrical fault within the ignition system?

[leftfootleashed]

Originally Posted by Magnumpi

Your description is exactly what my car is doing. I've yet to get to the bottom of it, after changing all ignition components, both fuel filters, both injector seals and cleaning the venturi (although it wasn't really dirty).

I've recently purchased a compression tester (foolishly from the market) got it home to test and it gives no reading, but not due to there being 0-compression, just the fact it's a Mickey Mouse tool!

I also adjusted the mixture and got it running to a standard that was nice and useable. However after 3 days of being fine it started playing up again.

Could it be some sort of intermitent electrical fault within the ignition system?

I'm not sure whether I'm more happy to hear someone else has the strange combination of problems as me, or disappointed to hear you've tried harder than me and still not solved them.

In my limited experience, I wouldn't have thought an intermittent electrical fault was likely, given how simple these cars are electrically and how you've replaced all the ignition components. Shouldn't rule anything out though.

One of the regulars (I can't remember who) advocates cleaning the fuel-related fuses to solve rough running problems, which sounds unlikely but he swears it works and I've been meaning to try it.

Another thing I haven't tried yet is taking the injectors out to check the spray pattern. If after the ignition's switched off they're leaking, that could explain the difficulty starting (flooded engine).

Just thinking aloud. Let me know if you make any progress and I'll do the same.

[Paul240480]

Your flame trap looks like one of the original type, I think.

If the pipe was split before it could be a cause for rough running but maybe not the difficult starting matter.... Maybe someone can confirm (or otherwise) my thoughts.

Not sure about that 'cap' thing. To my (uninformed) mind I wonder if it was fitted as some sort of bodge? Again someone with more knowledge should be able to identify it, one way or another.

Other thoughts:
Auxiliary air valve may be at fault, and/or the cold start injector ?

Good luck.

[DW42]

About a year ago I changed the injector seals on my 1988 B200E because they had gone hard. After doing this the car was hard to start and idled erratically. After lots of fiddling around trying to fix it, I replaced the plastic injector holders and the problems disappeared. It turned out that the plastic holders had also gone hard and perhaps slightly deformed, and two of them wouldn't seal again after being moved. Maybe this could be part of your problem? -- not too expensive to try.

David

[leftfootleashed]

Originally Posted by Paul240480

Your flame trap looks like one of the original type, I think.

If the pipe was split before it could be a cause for rough running but maybe not the difficult starting matter.... Maybe someone can confirm (or otherwise) my thoughts.

Not sure about that 'cap' thing. To my (uninformed) mind I wonder if it was fitted as some sort of bodge? Again someone with more knowledge should be able to identify it, one way or another.

Other thoughts:
Auxiliary air valve may be at fault, and/or the cold start injector ?

Good luck.

The cap does seem like a bodge, although the part fits perfectly. I can't see why someone would do that either. I've put it all back together without the cap now, and it runs as before (I was hoping it might solve something).

I'll take a look at those parts, and the "thermo time switch" which controls the cold start injector (think I've got that right) if I can find it. Any ideas for testing them? I guess for the injector just pull it out and see if it sprays on starting?

Originally Posted by DW42

About a year ago I changed the injector seals on my 1988 B200E because they had gone hard. After doing this the car was hard to start and idled erratically. After lots of fiddling around trying to fix it, I replaced the plastic injector holders and the problems disappeared. It turned out that the plastic holders had also gone hard and perhaps slightly deformed, and two of them wouldn't seal again after being moved. Maybe this could be part of your problem? -- not too expensive to try.

David

Thanks David. I'd read that the holders might have gone brittle, and might crack, but when I took them out they seemed fairly strong. Spraying them with carb cleaner to form a temporary seal should show if this is the case. I couldn't detect anything when I did this, but I might replace them anyway.