RiggerParish

Interesting. You are right, 2seater. With the volume it is hard to tell. Its at its loudest when I start the car from cold and it much quieter when warmed up after a drive. I have a receipt from the previous owner for a new instrument panel so I cannot be sure about the mileage. I would guess that it is over 100k based on its appearance.

Hello gang, I've been driving around all year with zero issues, just with what I thought was a typical power steering whine. I found the time to investigate with a stethoscope and then by removing the drive belt. With the belt off, the noise is still there. When I place the stethoscope just behind the balancer on the block, that is where the noise seems to be emanating from. Any mechanically inclined members know what is making this buzzing noise? Could it be the harmonic balancer itself or something more sinister inside? Thanks all, RP

I removed the switch to see if it affected the draw and it was obvious something wasn't right. A black wire had been spliced on to the blk/wht wire for the headlight switch. I removed it and repaired/insulated the blk/wht wire. Now there is no parasitic draw and battery is in good health. Any idea what that black wire could have been for?

The parking light switch works normally, when I press it the parking lights come on and when i press it again they go off. Then when I turn the ignition off and remove the key, the parking lights are off but the circuit is still drawing 400 ma.

I decided to figure out why the car battery drains when not driven regularly and I found out that the parasitic draw of 0.40 amps was being caused by the parking lights. As soon as I pulled the PK LPS fuse (position 10) the draw went down to 0.03. Looking through the service manual, at the wiring diagrams, is making me quite nervous. Is there any simple things to check first? For now I just remove that fuse when I park it for a few days. Thanks 1990 Coupe

Thank you Ed and Ronnie for the kind and encouraging words and thank you to all who contributed to what turned out to be a rather simple fix. It is quite embarrassing to be honest but I really don't mind, one day someone might stumble over this thread with the same issue and go out to the garage and fix it in 2 minutes. That makes it worth it! I have learned a lot of things about my car in the pursuit of a correct idle and as a result am a more competent Reatta mechanic! The idle is smoothing out and getting lower as I test drive it so I'd like to thank everyone again for your sharing of knowledge and patience. This drive past is for you!

Thanks, Ronnie. More often than not I miss things, but the help on here is invaluable and gets me back on track! Padgett posted a helpful chart a while ago with temperatures and the idle it should be at at those temps. At 80 degrees C the idle should drop to 625 but mine is never lower than 750 unless in gear. It also idles erratically on occasion between 750-900, up and down. So still more things to iron out, just happy to be making progress. Video of the new idle with ED22 displayed.

I do remember that. I was under the misapprehension that it was fully closed, in the correct position about a month ago. As you have highlighted, I am not perfect.

They were not right! I backed the idle stop out and it immediately helped the situation. it'll fire right up at about 1000rpm and then slowly reduce to about 900/800 then when fully warmed up it drops to 700/750rpm (600 in gear). Still a touch high which I could bring down to a really nice 625rpm with the help of ES09 but this override only works in diagnostics, correct? I guess I cant just set that as my idle and it memorizes it? We're getting there.

Sigh indeed. I should have went to bed. Located this stop screw. It does look like someone has been at it as I can see thread lock or something over it. this looks promising. Appreciate you saying that!

Its after midnight and I'm still in the garage. I put some tape over what I believe is the IAC intake port. So, if the butterfly valve was completely closed, the car shouldn't start? Well, the car did start and although it started at about 700rpm and settled there, it eventually crept back up to about 900/1000rpm.

Yes it is fine, I have attached a picture. No, it has never idled correctly as long as ive owned it. I have attached a picture where I spread some Rodico over the bottom of the butterfly valve to make sure no air was coming in and still 1000rpm. Im sorry to all if this thread is getting tedious.

It appears closed and im able to stall the engine by blocking air off here. Still idles at 1000rpm. Search continues.

This will be tonight's project. Thanks for the reply, Dave. I've already cleaned as much of the TB as I could without taking it apart, including the butterfly. My first try at fixing this was to clean out the IAC channel and all surrounding ports with carb cleaner. The IAC o ring and MAF gasket are both present.

It will choke and die, yes.

Thanks for the reply, padgett. I took the MAF sensor off to expose the butterfly valve and it appeared closed while idling. Since I am stumped and will try anything at this point, I'm going to check again. Thanks again

IAC passes testing on chart C-2 above. Changed connectors on TPS and IAC, have lights on all circuits. Still idles at 1000/1100rpm. IAC 0 counts at idle so the ECM knows the idle is too high! I am baffled and back to square one.

Home from work. Testing can continue! I'm waiting on new wires and connectors for the IAC and TPS, both of which have seen better days. Waiting on those parts I was able to at least check the 3 IACs I have and the results (in ohms)are as follows: IAC#1: A-B = 45.5, C-D = 46.2 IAC#2: A-B = 47.2, C-D = 48.0 IAC#3: A-B = 47.4, C-D = 47.4 A-D and B-C on all three resulted in infinite resistance. Although the tolerances (A-B, C-D) specify between 48 - 58 ....therefore none of mine really made the grade, but I think they were close enough. What were the results of your test 63viking? I also performed the test light procedure (shown above) and both blue/white and green/black wires produced no lights, while the blue/black and green/white produced steady lights! Now need to check for open or short, I guess. Hope the issue is in the connector. Cheers

Thanks for your posts, Ronnie. I replaced the ECM already, it came from a 1990 Reatta with normal idle. I was able to see the car running before the ECM was pulled. The IAC connector is looking quite rough indeed and multiple plastic parts of it missing. I tested all four wires with my meter and they tested good... but I found this IAC valve check in the manual which is the next step. I hate having to pull wires out of the harnesses but this might need to be done... I will trace oil pressure sender and IAC wires. Historical evidence of mice around harness! Thanks again

I found the hose and it looks good. I even blocked the vacuum off before the check valve by the intake and plugged it to rule out any leaks under dash and it idled the same at 1100rpm, unplugged it increased to 1300rpm. I have sprayed around all gaskets and I cannot find any leaks. I think I can rule out vacuum now as being the culprit. This is the current condition:

I see...so, Im looking for the cruise control vacuum switch under the dash?

With car running IAC value is 0 so all I could do in ES09 was increase the RPM up from 1100. Could not bring it down. Coolant was at 87 so commanded RPM should be 625. There is vacuum to a brake switch? Im looking around and I cannot find it anywhere. Is it the brakes or parking brake? Thanks

I suspected this, so a friend smoke tested the intake and any smoke was really negligible, the most i saw came from the EGR so I replaced that gasket. The first thing I did was clean the IAC opening as per the instructions on ROJ. The IAC that I messed with to bring the idle down was a junk one that I never connect. The one in the car now is new and never been adjusted by hand. When I said I was able to get the idle down a bit, it was by moving the IAC pintle by hand on that old IAC I mentioned. I am unfamiliar with adjusting the throttle plate. I have observed it when at idle and it appears fully closed. I will study some literature to see how to use ES09 tonight. 👍 Thank you Ronnie, Padget et al, I appreciate all the time you spend helping.

21 degrees Celsius is considered cold? I'll have to monitor ED04 when the engine warms up because even when its been running for half hour it still idles at 1100.

With some cleaning of the contacts the diagnostics stays on longer and I have more success accessing it, but I think it can still do with more cleaning. With the car in spark and at idle this is what it was telling me. TPS/ED01 - .40 CTS/ED04 - 21 Injector pulse width/ED06 - 5.3 Oxygen sensor voltage/ED07 - .50 Spark Advance/ED08 - 33 Battery voltage/ED10 - 14.5 Engine RPM/ED11 - 1087 VSS/ED12 - 0 Spk angle/ED16 - 0 OLD PA3/ED17 - 178 Oxygen sensor cross counts/ED18 - 20, 10, 6 (This value was not steady and changed between these numbers) Fuel integrator/ED19 - 128 BLM fuel (Block learn mult)/ED20 - 128 Air Flow/ ED21 - 9.0 IAC/ED22 - 3 MAT/ED23 - 13 Ignition cycle counter/ED98 - 9 I'm going to pull the climate controls again to clean more as this is progress. Any glaring discrepancies? Thanks