new 1989 coupe owner - couple of questions

Hi all, I'm the proud 9th owner of a 1989 coupe 2.0e (UK), & I like the car, though predictably it's got a couple of issues:
1. Once the engine has warmed up, the revs pulse at idle, between 900
& 1100 rpm, about once a second. Funnily enough, my last bmw did a similar thing, & belive they both have Bosch management systems. Googling this group suggests that this could be a vacuum leak, or a bad / dirty ISV. Could there be another cause? Occasionally the car will stall while changing gears, which is probably related to the bad idle.
2. The accellerator pedal's resistance increases in a step, towards the end of it's travel - what's this? It certainly seems to make the car go faster!
3. The spare wheel bay is collecting water, is there a diy solution to this?
Many thanks for any advice, Jamie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Could be a defective Oxygen Sensor AFAIK too. A lot of possibilities with this problem. What did you check? Maybe a test of the system components done at the ECU wiring which should be outlined in the Bentley repair manual is needed. I am not sure if the Bentley manual covers the UK cars though. :-(

I was going to suggest this for both #1 and #2, maybe the throttle body plates are sticking and not freely moving and/or not returning to their stop/resting position.

Check the taillights to make sure they are still sealed to the body. Also check that the rear hatch does not collect water and that it drains, if it has any drains.
Good luck with it!
later, dave (One out of many Daves)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jamie, Congrats on the car. 1. It could also be the oxygen sensor. Try unplugging the ISV (clean it anyway - with "Throttle Body Cleaner" _NOT_ "Carburettor Cleaner" - TB Cleaner is more mild and won't damage the ISV's seals) and the Oxygen sensor individually and see if the removal of one or the other from the engine mgmt has any effect. Replacing the OXS isn't too bad nor expensive, once you've got it unscrewed (that's the hard part), you can splice in a 3-wire Bosch for, say, a Ford. 2. The added resistance is probably from a second butterfly opening in the throttle body. 3. Drill a hole in the bottom of the spare wheel bay.....just kidding.....you've probably got a leak in the weatherstripping, although it could be from any one of a number of places. Find the leak - use a hose, or a carwash - I've even heard of one person who stripped the trunk, and then had his SO close him in the trunk with a flashlight and then spray the car down to find the leak - I guess going that route depends on how much you trust your SO.......or know how to open the trunk from the inside...... Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<snip>

Come on, guys! Just fill up the trunk with water, and see where it leaks! ;o)
--
Gio



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.