2seater

I had calculated the relative axle ratio some time ago due to the 91 also running a taller tire, but the effective ratio is still lower. I estimated the change would be the same as an earlier Reatta running a 3.25 final drive. Essentially the difference works out to a bit over a nine percent rpm change at the same speed. You could get the same effect by running a 23.5” diameter tire🤨

I have wondered about the LS conversion also. I am pretty sure it is all aluminum also. There are only a few engines with the GM metric bellhousing pattern which is peculiar to only a few engines, mostly the 60deg GM V6’s. I must say if I had things to do all over again I would have used the Series2 engines to start with, much like Daniel has done. If you start with a higher baseline, performance mods are generally magnified. I have heard of people doing a final drive ratio change, which I believe is relatively straightforward but I don’t have any example. GM did that, 3.33 final, on the 91 Reatta. It is my belief that was done to help the relatively soft low rpm torque of the Series 1 TPI engines. They do have a higher torque peak, by a small amount, but at a much higher rpm, which is where the increased hp comes from ad well.

I know a lot more now than two decades ago. The funniest thing about this resurrected thread is my latest project is a supercharged variant🤔

I also saw that light in a vintage car magazine. It looks very nice and the design is such that the cooling fins on the rear of the housing have the same shape and contour as the back of a standard bulb so would likely work with out flip up headlamps. $400 is a pretty steep price IMHO, so not a casual change.

If memory serves, it is a clip on fitting with a sort of hairpin retainer, I don’t remember exactly. The air lines are 1/8” plastic and I believe those kits are available. The two struts are tee’d together with a single line to a place of your choice for a Schroeder valve.

I have Riviera struts on my car since the turn of the century without air in them and have never found that to be an issue. The strut is essentially the same but it has an external air bag added to the upper end, sort of like a coilover. Initially I added air lines and a central schroeder (tire valve) inside the console. It will jack the car up if desired but it seems most people want to go the other way. I am pretty certain there is no air in the strut after a couple decades and perhaps the rubber bladder is now inoperative, I do not know. When I get the car out in a little while I will try adding air to find out.

Slightly under diameter, about 3/8". 235/60 are about a tenth of an inch large. Not big amounts, but does have a small effect. Speedo tends to over report speed slightly with stock size.

No mention of mileage, pics under the hood or in the trunk?

I have the Hella E-spec lights with 80/100w bulbs, and have had for many years. They eventually killed an expensive and rare 1990 headlight switch, actually a couple of them, but then we did a relay project, which solved multiple problems. Today, very little monkey motion is required. Just add the readily available aftermarket relay harness which is completely reversible, makes LED's function properly, feeds high powered incandescent light and makes whatever stock bulbs you are running, better by providing full design voltage. For roughly $15, it supports and improves whatever you are running. YMMV

The one downside to some available tires is the speed rating is lower than the factory recommendation of an "H" speed rating. It isn't only the raw speed rating that may never be used, but it is also the stiffness and sidewall construction that does affect handling. I was just working with my EEPROM programming yesterday and the fuel cutoff is 125mph, which seems a pretty good match for the factory 130mph tires. Despite the relatively small size of our cars, they are as heavy as a LeSabre of the same year, and 65% of that weight is on the front tires. YMMV

I am going to stay out of this one as well except to mention one item: I have repaired two different Reatta's that had broken wires inside the big rubber boot in the hinge area. It is a poor design that bends the wires each time the door opens and closes. There are no points to disconnect the wiring so you need to work on it in an uncomfortable position. A better design has the two ends of the harness between car and door to be offset vertically from each other so the wire bundle rotates rather than bends. Good luck

I have two of them in my spare parts. One is likely the original as it is fairly stiff and the only markings are the numbers 192 and 172 directly opposite the other number and what appears to be a capital AB with the letters touching each other. The other one is nice and soft but it is lying loose without the original packaging and I am guessing it may be a Dorman "Help" part. It does have a part number cast in: 6042316 M I have a couple Dorman PCV grommets in the package with the part number 42311, reinforcing my guess the above number is Dorman

I honestly don't know but it does seem to be implied that it might be the case. I would think that it wouldn't permanently change the idle, but it might affect it until the ECM learns the new normal? Sort of like the fuel integrator and block learn. The ECM can adjust the fueling to maintain the desired mixture but it has only limited ability to do so and needs to be in a range that it can adjust for.

Maybe there was a running change in the TPS recommendation? That is such a huge range I don't know how that would work but I was curious how our tribal knowledge came to .38-.42 for idle setting. According to my 1990 FSM, the acceptable range is .33-.46, a bit wider than we generally use as a guide but further along, in the section dealing with part replacement, it does recommend .38-.42 for the setting on installation as it is in the center of the acceptable range. Of course, I noticed it also made the point that if there is either code E021 or E022, the ECM will generate a substitute signal for the TPS and it will also have a high idle.

I went through a very long and involved project to be able to get the doors to close after adding relays for the headlights, and then the harness discovery, necessitated by LED's, and that worked with no cutting or splicing. All are valid, but the best thing about the harness is it improves any lighting system, no matter the type, by supplying the full system voltage, bypassing those skinny little ~16ga. wires.

I have never used the rear defrost either and it has been a summer only car since the mid 90's

I can't find any relatively closeup photos of my car which was tinted back in the 90's. It sounds like you are already pretty experienced with having tinting done. Franklly, mine really needs to be redone, but I am honestly surprised by the number of Reatta's that are still clear glass, even in southern states. It seems like a no brainer to me with the size of the greenhouse relative to the interior. My first brand new car, a 1975 AMC Pacer, had a somewhat similar layout, and was hot as can be in the summer. The interior takes a beating, the A/C has to work harder etc... The only thing I can say from my experience is the rear should be a dark tint, maybe not limousine level, but dark and the side widows no more than 50% or the view out the side at night, especially at intersections, is very challenging, local laws not withstanding. I don't know if available or not, but a gradient tint on the side windows would be just the ticket, dark at top and lighter below or photo reactive like photo gray type glasses.JMHO

I don't know what ECM relay is being referred to or if it even exists? There are multiple 12 volt "hot in run" inputs to the ECM, fuse #5 being a primary one, and one B+ fusible link hot at all times. Much of the functioning of the ECM is to switch grounds on and off to make things operate, injectors for example; are fed a constant 12v with the key on and the ECM switches the individual grounds to make the injector fire. Many items are like that, they have power directly and the ECM does much of the grounding, but not in all cases. In the case of the IAC, power and ground come from the ECM and there is an indication of the source being "battery". See the attached diagram. I don't quite follow the symbology, but it looks like a pulsed current operates the IAC, and maybe voltage can be measured between A-B and C-D??

The one item that is sort of close to the IAC is the EGR which does have a "hot in run" connection, plus the ECM grounds. Technically, the injectors do too. It should be pretty easy to discriminate between them, but they are the only other items that might "click" when activated, so it is unlikely but?? They should be dead with key off too.

I agree with the above, which sounds like it comes from experience🙂. I did double check FSM wiring diagram and the wiring for the IAC connects to the ECM only, no other source of power. I couldn't venture a guess what might be keeping the ECM awake and trying to adjust idle speed on a dormant engine?

I am somewhat out of ideas at this point, but even though it does sound obvious, you should check that there isn't some sort of throttle cable anomaly causing the throttle to hang up at times. When it is in one of its high idle moods, just manually check the arm under the hood to be sure it is in closed position. The other item to watch is the IAC counts in diagnostics. You need to sort of develop a feel for this one as it isn't a static number. The counts will increase when you open the throttle so it is ready to catch the engine and let it down smoothly if the throttle is snapped closed and you can watch the counts as the engine warms up where they should slowly decrease to bring the idle down. Once you have a feel for what the counts are at a good warm idle, you can see if they are out of that range when it acts up, either high or low. If you are familiar with diagnostic overrides, you can manually close the IAC from the driver's seat to see if the idle can be forced lower by overriding the IAC.

Any time things are changed or adjusted, the ECM may need time to fill in the desired settings, so driving it under varied speeds and loads is a good idea. You can sometimes see the difference by disconnecting the battery so the ECM starts over from its base programming. It may run better or worse for a bit until it fills in the blanks. As Ronnie alluded to, sometimes a sensor is out of range enough to cause the ECM to adjust, but not out far enough to set a code. That is much of the reason as a test to sometimes disconnect a sensor, like the MAF for example, which forces the ECM to substitute a programmed safe setting. It is possible for an ECM to be bad, but not common.

The TPS range sounds like it is spot on now. The ECM must learn the new parameters now that the sensor has been corrected so it will take a little time for it to adjust. Even better is to disconnect the battery ground for a couple minutes to force the ECM to start over and learn from scratch. In any case, It really needs to be driven for a while for changed settings to be accommodated. A new O2 sensor as suggested is always a good idea if the existing ones history is unknown or you are chasing a mileage issue. It is usually a good idea to make one change at a time to see the effect but the O2 replacement is an exception.

Yes, loosen mounting screws and rotate to .38-.42v. Does it increase with throttle as it is now? I don't remember ever seeing one that far off unless there were other issues.

A darn shame for sure. I hope the future is brighter.