Bushwack

The Reatta listed belongs to (almost) everyone's favorite multi-Reattas owner, Steve S. I spoke to him recently (he's doing well and as ornery as ever 😀). I know it's difficult for him to have listed the car as each are like his children. But as the market is as hot as ever,... At least we know the buyer will get a meticulously well-cared for car.

A new ECM fixed the problem (after replacing the IAC a couple times and fixing a vacuum leak). Thinking back, a few years ago I had another '90 Reatta with the same problem. I lived with it for a while (after various failed troubleshooting efforts) and the car eventually fixed itself.

Five weeks ago I purchased four Kumho Solus TA11 All-Season Tires from Amazon at $88.10/each (now priced at $95.20). They were shipped free from North Carolina to Los Angeles. Tirerack had them priced at $95.00/each (now $102.00). Not sure what possessed me to think of Amazon for tires. But I purchased them using my Discovercard, which gets me 5% cash back to use for a future Amazon purchase (I'm grandfathered at 5% - I think most others using their Discovercard get either 1 or 2% cash back).

Excuse my ignorance, but would the higher setting make for a higher idle? If the setting was .33 - .38, would the idle be lower then the recommended .38 - .42?

Both horn buttons on my '90 coupe work intermittently - maybe twice out of ten attempts. I'll get a short toot from either button. I know the horn works as I've accidentally set-off the factory alarm. After making sure the fuse is OK, any suggestions/advice where I should first start troubleshooting (before taking off the steering wheel)? Thanks.

For what they are, the SIlverstars work fine. But when your daily driver has LEDs, there is a huge difference.

I decided to install Silverstars for two reasons: I didn't find the answer (just not in this forum) that I was looking for regarding LEDs. And, as I consider the Reatta a second car, I'll rarely drive it in the evenings. The Silverstars were $20/each and installed in 30 minutes. LEDs probably a bit more costly and more time consuming to install.

Thanks Dave - appreciate it.. Having read the thread (I hope everyone with cataracts has since taken advantage of medical science), my take-away is there is no plug-n-play option for LEDs for a 1990 Reatta. When it comes to electricity, my limits are turning on and off a wall switch. If a harness or relay is involved to get LEDs, I'm going with the tried-and-true SIlverStars

Can the OEM headlights be replaced with LEDs (plug-n-play scenario)? I've been doing some research and have read that it's possible, but there's an issue with the headlight covers (either they will not open or close). I also read that an additional relay needs to be installed for LEDs. And lastly, I read with today's technology, it is a simple installation. Of course, nobody provided documentation or which LEDs are being referenced.

UPDATE: Problem resolved. After lots of troubleshooting and at last resort, the ECM was replaced (thanks Jim Finn), moving the old PROM to the 'new' unit, and life is good. Car idles at normal temperature when in gear slightly higher then I'd like (800 RPM, I think normal is 650-750). Nevertheless the car now drives as well as any Reatta I've owned. In retrospect, maybe I didn't need to have the IAC or TPS replaced. But assuming they were original and not too expensive to replace,... Thanks everyone for your input

So not to keep anyone hanging, I dropped the car off at a mechanic who works on cars pre-1996. If there is something electrical happening, it's beyond my expertise. I did send him some of the comments/suggestions everyone made. I hope to have more information by the end of next week. Thanks.

Original paint.

Thanks folks for the suggestions. Curious...would any of these be the power relay - https://www.rockauto.com/en/catalog/buick,1990,reatta,3.8l+231cid+v6,1019911,electrical-switch+&+relay,accessory+power+relay,2944

I drove the '90 Reatta over 40 miles yesterday. This morning, the car would not start. I was going to adjust the headlights this morning. When I opened the hood, I heard ticking noises (the car was cold). I went and tried to start the car,...dead. I recharged the battery and took the car to the mechanic. He said the problem is the IAC. He replaced the original IAC a few days earlier. The next day at his shop, he was going to replace an oil pan gasket (he had the car on a lift from the day before). He popped the hood and heard ticking. Went to turn on the ignition,...dead battery. He determined it was the IAC ticking and draining the battery. He replaced the new IAC with another new IAC. I took the car home last Friday afternoon, didn't drive it until Saturday night. Drove it again on Sunday. This morning as I popped the hood to adjust the headlights, I heard the ticking and...dead battery. Mechanic thinks I should replace the ECM (of which I have one en route) for this and other reasons surrounding idling issues (isn't that the job of the IAC?). He feels the ECM is not communicating with the IAC. Question is...could there be a short somewhere and if so, how do you determine where it is? Installing another ECM, if there is a short, solves nothing. There are no vacuum leaks and the TPS has been replaced. EGR is fine. There are no error codes. This has become frustrating in what I feel isn't a difficult problem to solve (I wish I was mechanically inclined). Any suggestions are appreciated.

Appreciate it!! I saw those bulbs but I question why the tip of the dome is gray. I did find these (https://www.amazon.com/gp/product/B000BLNTGK/ref=ox_sc_act_title_5?smid=A5H1OAYE8AOI9&psc=1), which are the same as this (https://drivcat.com/overlays/part-detail.aspx?brand=WL&PartNumber=BP890&pt=Turn Signal Light Bulb&lu=1990 BUICK REATTA&vin=) and appear OEM (originally from Wagner). I purchase a few and will install them this week.

Bulb needs to have a round bull-nose top. That point at the tip causes problems with the housing (bulb is too long).

I'm realizing that GE (as it appears) discontinued the 890 bulbs (when did this happen?). Anyone have a recommendation for a substitute (1990 passenger front corner)? Or, anyone have two bulbs gathering dust on a shelf he/she would like to part with for a reasonable sum of U.S. currency? 😁

About 4-5 years ago, I spoke with two Reatta buyers. One purchased a white/burgundy '90 vert for $8,800 (asking price was $10,495). The other purchased a '90 white/tan coupe for $5,500 (asking price was $6,995). Neither car needed anything and were in great shape inside and out. Both were purchased from eBay. I don't put much weight behind Mecum or B-J sales figures. That's the 1% of the 1% that live in their own universe. For a true purchase price, need to speak to the buyers. Meanwhile, if you see a car you like, no harm in making an offer.

So... this morning I reconnected the battery and the car had difficulty maintaining idle (had to help it get to 1200 RPM to warm up). After a few minutes, idle was at 700-800 RPM. I took the car on a 25 mile drive of mixed city/freeway traffic. I noticed when I got off the freeway to return home, idle was at 1600 RPM when in neutral (the car felt like it was pulling as I came to a stop). I returned to the freeway to go home, eventually got off the freeway after another 8 miles going between 55-70MPH, and idle was normal at 600-700RPM. A trusted mechanic who no longer has his shop mentioned I have two separate problems. The cold start problem (he suggests to replace the cold start valve - isn't that the IAC?). For the high idle, check for vacuum leaks (there are no vacuum leaks). Might also be a throttle body issue, but he said that should be a last resort. The IAC and TPS have been replaced (and set to specifications) and there are no error codes. I would think if a vacuum leak exists, idle would always stay high and not return to normal after 20 minutes. Before replacing the ECM (as some have mentioned because of the idle fluctuations), I still think the issue is something else. ...and if I was mechanically inclined, I wouldn't be posting this - asking for advice. 😁

Thanks folks. I think what I will do is disconnect the battery, let the car sit overnight, re-connect the battery and take the car on a 20 mile drive of both highway and stop-n-go traffic. Afterwards, I'll pull codes and see what we find.

As the OP, here's a follow up: Mechanic determined the reason the RPMs are inconsistent (very low on a cold start and high when hot), is the ECM is not sending a signal to the IAC. Mechanic thinks the problem is the ECM (the TPS, O2 sensor, and MAF are good). There were two vacuum leaks that have been repaired. He did re-install the TPS. Questions... the problem still persists. Because the TPS was reinstalled, should I drive the car for 10-15 miles so the ECM can 'adjust' (is this necessary)? Is there something else to look at? *I* would think the ECM would be consistent - either it sends a signal or it does not. Could the ECM be the problem?

Other then a scratch on the drivers side (too deep to make it go away) and a small tear on the driver's door panel (anyone have one in gray?), it didn't take much to make it shine. Need new tires and if anyone has one exceptional wheel at an exceptionally good price, send me a PM.

TPS....Throttle position sensor???

Hi Folks, I posted this question on FB. But in case some do not log participate in the FB forum,... Just bought a '90 coupe and I never had this problem: At 86,000 miles, the engine runs well but intermittently, whether hot or cold, the engine will rev to 2500 RPM and not decrease RPMs. There are times I'll get a normal cold start (1,200 RPM and eventually settles to 800 RPM). There are times I'll get a normal hot start. And there are times it gets to 2,500 RPM and stays there. Putting the transmission into gear does not bring the car down to a normal idle. I've changed the idle control valve (twice), clean the fuel injection - the engine will still rev intermittently at 2,500. Any suggestions on fixing this problem is appreciated. Thanks.

Haha.... I thought I swore off Reattas a few years ago when I sold my last convertible. Majority I owned were show cars or near-show cars. This one is in good/very good condition aesthetically. This is a Reatta that will not irritate me if it gets a door ding or a scratch. Bought the car first, checked the VIN second (isn't that how it's done?). Has lived its entire life in SoCal (within 15 miles from my home). I was acquainted with the gentleman who owned it through the local Buick chapter (he passed away last summer). He owned several Buicks and tinkered with them for years (he stopped driving a few years ago). A couple members of the local Buick Chapter reached out to me about both Reattas (I wasn't actively looking for another Reatta). ...and here I am with Reatta #15.