'86 360 GLE Inj. prob (diff to describe)

[pettaw]

difficult to describe, but basically the engine seems to be holding on to its revs too long, or longer than any other car I've driven.
For those of you who don't know the history of this car. I got it about a month ago with duff electric windows, sunroof, etc etc etc. Basically got everything working apart from the gearchange which is lying over to the right, so that 5 is very difficult to engage without really bending the plastic shroud, I've replaced all the linkages and the bracket at the front as well. Any ideas on that would be appreciated. I do know that some muppet replaced the diff and g/box about three years ago. Could it be the wrong box in the car? Also there is a slight bump-bump-bump noise at around 30 mph goes above this and below it. Related to road speed and not to gear.

Anyway I digress. My main problem is that the engine seems to be holding onto its revs too long. I had to replace the injectors and clean all the gunk out of the AMM, TP etc etc. to make the car come anywhere near the correct CO content. Now tickover is perfect. Anyway, the engine holds onto its revs for a long time and makes gear changing difficult as you've got to wait for the revs to come down again to engage gear smoothly. I think I've adjusted the TP to the correct spec, but is there a better way to check the adjustment rather than ramming a feeler gauge up the gap and seeing if it binds or not. FYI if I put the black adjuster all the way in I get about 600 RPM and the throttle butterfly switch has been confirmed as working correctly.

Sorry for the long post. Any suggestions would be welcome.

Andy

[Peter Milnes]

Sounds as if the throttle cable is sticking inside it's outer casing. This would certainly give the symptoms you describe. Either that or the throttle quadrant may be sticking at some point in it's travel.

All the best, Peter.

[pettaw]

Thanks for the reply Peter. I checked the throttle and it seems free. The valve seems to be contacting its stop properly. I was wondering if I should try readjusting it and if so is there a better way than shoving feeler gauges in?

Andy

[Peter Milnes]

It could be due to a worn throttle spindle which is not letting the flap close properly. This could be due to the fixing screws becoming loose or to the spindle bearings becoming too worn to keep the butterfly central.

All the best, Peter.

Just an idea - if your auxiliary air valve has lost its 12v feed it will only be able to close down via engine heat. Whilst on the move underbonnet air flow will tend to keep it open - come to a halt and revs will be high. heat soak will quite quickly close the valve and revs will drop. Regards (mollusk300 - a new member)

[pettaw]

Thanks for the idea Mollusk. The idle itself is normal or what I would say is normal. If, for instance you rev up to about 3000 it'll take about 4 seconds to drop to idle which seems to be too long to me. I've never had a 360 before, only used to the renault powered 340's but I would have thought that the revs would drop more quickly, like they do on the 340. It makes changing gear smoothly difficult. I was wondering whether you can adjust the throttle butterfly on the throttle body in any other way than the Haynes way of shoving feeler gauges into the gap, seems not that accurate to me. At the moment I get about 700 rpm if I screw the idling screw all the way in. Should this be lower?

Andy

According to Volvo specs idle speed should be 15 r/s (900rpm) on your model.
The Volvo way of adjusting the throttle plate is also by insertion of feeler gauge (actually feeler wire) size should be 0.05 - 0.1mm

Okay lets think logically about the problem - mechanical stiction, you seem to have ruled that out. Gummed up AMM, would be overridden by closure of throttle plate. Throttle plate not closing ?, missing incorrect or ineffective return spring perhaps.
If you rev the engine up and release the throttle pedal does the throttle snap back to its stop quickly ??. If it does not you seem to have a mechanical problem with the linkage. If it does close but revs remain high the problem is almost certainly excess air bypassing the throttle butterfly, check:- butterfly/spindle for wear, throttle body to manifold gasket, gasket between inlet manifold and head, the inlet manifold itself for cracks or loose vacuum pipes, vacuum pipe to brake servo, piping to and from aux air valve.

Try above (brain fading now) regards mollusk.

[pettaw]

when you mention feeler wire you got my brain working. I wonder if I've simply set the gap too wide? I cleaned out all the throttle body, AMM, etc etc 'cos it was all gunked up. The gap was huge after this and I couldn't get the car to idle properly at all, so I readjusted the throttle plate using feeler gauges, but I wonder if it's still too open. The revs don't stay high, they just don't die away as I would expect them to do.

If you are using a flat feeler gauge the setting will be wrong to a greater or lesser extent depending on the width of the blade. Use a feeler wire (the shank of a correctly sized jobber drill is perfect)Obviously after adjustment bring idle speed back up via air bypass screw. If primary butterfly setting is indeed way too large it could well give the symptoms you have.

Keep at it - there is an answer! mollusk

[pettaw]

I've closed up the throttle butterfly screw, and I don't think it's made much difference, so I'm now left with other options, like perhaps leaking vacuum hoses. The hoses to/from the A.A valve don't look like they're the tightest, so they might leak upon the increased manifold vacuum when the revs are high and the throttle is closed.

Too hot to do any more work today, continue tomorrow.

thanks for the ideas,

Andy