super eta with low idle speed - solved

[TSMacNeil]

I can already tell that tn535i is a better resource than me on this...so where we differ, I'd go with him. Having said that, (and just to be clear) if you get a small mirror and have a look under your throttlebody with car off...it will be real obvious what has to happen. You dont have to disconnect anything at all, IF you can get to those screws and just loosen them a tad. Once you do that, nudging the switch a little until you can work the throttle and hear a click is all you need to do...then just tighten down those 2 screws...recheck it by hand to be sure it clicks as soon as you begin to twist the throttle by hand....then your done.

Since you have positively indicated that this "click" is NOT happening, this is the first thing you need to do for your idle....we can go from there if need be.

By the way, the "click" is pretty loud and mechanical...you can actually feel it...this will be easier than you think.

Post your findings here and be brave, it wont bite ya...

In depth idle factoids (courtesy of Rod Paine again):

http://www.mesaperformance.com/faqs/idle.html

[TheDuke88]

Or I could lose my car under 4 foot snow drifts. Looks like the TPS has to keep itself warm as is til I find the car.

Peace. Thanks for easing all my worries about the adjustment.

(It is strange but I think the Bentley has more subparagraphs that say "NOTE ---- On all 1988 528e models, the previous 4 pages of instruction does not apply.")

[TSMacNeil]

Yes, the Bentley is a must-have, but you have to watch what you're reading!

Happy shovelling!

[TheDuke88]

Finally warm enough to adjust TPS....

Afterwards, took it for a spin and there did not seem to be a change. In fact, stumbling on acceleration got a bit worse. So I put it back to where it originally was.

When it was loose and I was trying to hear the click - it is there but faint. The position of it makes it very hard to adjust it gently, so I let it stop opposite where it originally was. Could it be a more finite movement that I need to do or is it either set to one twist til stop or the other way one twist til stop? Or is it shot?

Also, just to see what would happen. I loosened both screws slightly, then started the car. While it ran, I shifted the tps slowly from one extreme to the other and I did not find a obvious position that made the idle any better.

Other questions:
1) Is the ICV supposed to have an audible rapid click when running normally?

2) While it was running and I was searching for an idle change, I unplugged the ICV. After about a minute, my idle surged/pulsed from 500 to 2000rpm until I shut it off, plugged it in and restarted. Fine. Would this suggest my ICV is OK?

Why can't 'poor idle' just be a blown fuse.....
...or low idle fluid.

[Bimmerguy2002]

That is a ghetto way of adjusting the TPS, just use a muiltimeter and do it right.

[Area 52]

Follow the Bentley:
1. verify throttle plate adjustment...remove intake bellows and if there is a fingernail width gap between the plate and the ridge-stop on the bore, it's good. (may need to clean out first with throttle body spray cleaner-open fully to clean back side of throttle plate and wipe with cleans rags. Adjust clearance with screw on linkage (head of screw faces forward and may have clear tamper cap that pulls off).
2. use ohmmeter setting of DVOM to adjust TPS (again, refer to Bentley).
3. remove connector on TPS and clean (may see green corrosion on the TPS tabs-disposable emory board and contact cleaner spray. Spray harness connector end too.
4. use ammeter setting of DVOM to adjust ICV (refer to Bentley).

Report back

[TSMacNeil]

Obviously, if you have a VOM, adjusting it for continuity at plate closure is best. I dont recall if you have a VOM, but if you are unsure of whether you have it set right, do what I did and pull the TB off and adjust it with a VOM.

Very little "ghetto" about whether the switch works or not. It either does, or it doesnt. If you arent sure about it while its installed, just pull it off and do it the easy way with a VOM.

As we discussed early on...the TPS operation is crucial...you have to set it so that it operates properly...THEN address the idle from that point. If that means pulling the throttlebody, pull it.

Only then can you address the idle properly from that point on.

Yes, ICV "buzzes" with ignition.

HTH

[TheDuke88]

Follow the Bentley:
1. verify throttle plate adjustment...remove intake bellows and if there is a fingernail width gap between the plate and the ridge-stop on the bore, it's good. (may need to clean out first with throttle body spray cleaner-open fully to clean back side of throttle plate and wipe with cleans rags. Adjust clearance with screw on linkage (head of screw faces forward and may have clear tamper cap that pulls off).
2. use ohmmeter setting of DVOM to adjust TPS (again, refer to Bentley).
3. remove connector on TPS and clean (may see green corrosion on the TPS tabs-disposable emory board and contact cleaner spray. Spray harness connector end too.
4. use ammeter setting of DVOM to adjust ICV (refer to Bentley).

Ok, so....
1. throttle plate was already adjusted to .0015 prior to moving the tps.
2. I used the ohmmeter to test for continuity/no continuity and per Bentley Table k, my tps was working fine prior to adjusting it. (Just couldn't hear a distinguishable click upon manually moving throttle.)
3. All connections were spotless, but I cleaned them up and added electrical goo. (male&female)
4. Per bentley, my ICV is controlled by my ECU (motronic 1.1) and therefore not adjustable.


Allow me to ask what exactly is the DVOM setting on an ohmmeter? My digital multimeter has AC/DC Voltage, DC current, resistance, Frequency, Temperature, Diode and Audible Continuity test < which is what I used to check TPS.
Thanks.

[Shawn D.]

4. use ammeter setting of DVOM to adjust ICV (refer to Bentley).

Allow me to ask what exactly is the DVOM setting on an ohmmeter? My digital multimeter has AC/DC Voltage, DC current, resistance, Frequency, Temperature, Diode and Audible Continuity test < which is what I used to check TPS.
Thanks.

I'll rephrase #4:

"... use ammeter setting of DVOM..."

"... use the ammeter setting of the Digital Volt-Ohm Meter..."

[TSMacNeil]

Ok, so....
1. throttle plate was already adjusted to .0015 prior to moving the tps.
2. I used the ohmmeter to test for continuity/no continuity and per Bentley Table k, my tps was working fine prior to adjusting it. (Just couldn't hear a distinguishable click upon manually moving throttle.)

Lets work from here:
1. Excellent.
2. Was this done at the connector while TPS still mounted on the underside of throttlebody?..or have you removed it?

Lets focus on the "tps working fine prior to adjusting" Do you mean that if you work the switch with your finger, you see (or tone) the "make/break" of continuity? If so, all you know is the switch itself works...which is good. However, what we are all trying to determine is does the switch operate when it's supposed to?
This is the adjustment that must be made. It is possible that attempting this while the throttlebody is installed is complicating things too much. I recommend you pull the throttlebody off (need a gasket for this) and just flip it over to set the adjustment using your ohmmeter (continuity setting) at the connnector so that the switch works when the throttleplate hits the idlestop. The "clicking" is incidental to its operation...its possible the switch is inaudible, the V-O-M is the best tool to use.

[TheDuke88]

Continuity was checked in place.

Unfortunately, the car's repair has to wait a while. Family of two cars - the other car, a Saab, became a true SaabStory two days ago. I hesitate taking a "well-enough" car apart now. In a few weeks, we hope to have another vintage BMW in our midst. But for now we are down to the one.

I'll get back to on this when I can attempt to remove throttle and start fresh, right side up. Thanks for your help.