

| Subject: | Re: '88 lurching at 2500-3000 rpm |
| From: | Shawn Wright, SMUS Network Analyst |
| Date: | Mon, 11 Mar 1996 19:57:19 PDT |
> for some reason, i was thinking they bent it outward, not inward. might want > to ask the list and get the opinions of them what has done it. but i think > that the cleaning would be a good thing. i think you can get some "cleaner" > in a can from Radio Shack or any good electronic wholesale place. > > >How do you adjust the idle? Mine is at about 1100rpm & surges from > >1000-1250 or so regardless of temperature. I'm thinking this may be > >another cause for the surging - is this likely? > > hmmm. that sort of surging is usually associated with the coolant temp > sensor ... the blue sender gizmo on the thermostat. it's a $12 part (don't > forget to get a NEW o-ring with it ... another $2!!!). it's telling the > engine that the coolant isn't warm yet. maybe. removed the connector & idle went up right away (engine hot). When given any throttle, engine sounded like it was choked (running rich) & almost stalled. Back to normal when plugged back in. I guess this means the sender is OK?? > another possible surge cause could be the adjustment of the throttle switch. > if the engine seems to idle ok with the throttle cracked just a tiny bit, > this might be the cause. it's the little gizmo located on the air intake > plenum (the silver "spider" just to the left of the air flow meter) and > down kind low, near the throttle cable connection. it has a small adjusting > screw (and it is EASILY damaged!! be careful) which should be set at the > factory and blobbed with wax to keep people like me and you out of it!! :) Didn't seem to matter if throttle was touched a bit, although there's a vey fine line between idle & 2000rpm... Wait a minute - you said switch... hmmmm. I looked everywhere, but there is NO switch anywhere connected to the throttle linkage - just a standard set-screw type of thing. My Jetta has these switches for idle & full throttle, but I can't see any here - it loooks pretty much like my old CIS injected Scirocco... Is it possible this switch has been removed??? > another surger cause could be the idle mixture air valve ... on the rubber > boot that goes from the air flow meter to this silver spider, there is a > smaller rubber hose that runs off toward the back of the bus. it eventually > goes to the crankcase breater thing in the middle of the back of the engine > (back is back). somewhere along that hose is a thing with an electrical > connection. it looks like a metal cylinder stuck off at an angle to the hose. > this thing works like a PCV. sort of. when the engine is cold, it's supposed > to allow more air to recirculate, and raise the idle. you might try removing > it and cleaning it with spray cleaner (or brake cleaner) to remove any > gunk and stuff inside. several folks have reported smoother idle after doing > that. > > and lastly (that i can think of), check all the electrical connections on the > engine. especially the ground strap over by the ignition coil ... make sure > it's connected tightly on both ends. and over in front of the right rear > taillight (we got "front taillights?? :) there is a bunch of relays and such. I checked all the plugs I could find, but no relays aside from two inside a box over the coil... Are they in a different place on an '88? With those under the dash maybe? > the big one is THE idle stabilizer what controls your idle. you might pull it > out (it's a bear to get it off that plugboard) and clean the contacts and > put it back. one fellow said that cured his idle problems. > I'll pull all those under the dash & clean just in case.. Thanksfor all the info so far...! Shawn. good luck. > joel > *--------------------------------* | Shawn Wright, Network Manager | | St. Michaels University School | | 3400 Richmond Rd, Victoria, BC | | Canada V8P 4P5 | | (604) 592-2411 Fax: 592-2812 | | swright@smus.bc.ca | *--------------------------------* I haven't lost my mind; I'm sure it's backed up on tape somewhere!
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