2seater

It does get confusing when many numbers get bounced around at the same time🤪. I did mean that the O2 sensor reading, ED07, should be constantly moving. The usual range it circulates in is .2 (lean)-.8 (rich), with the crossover between rich and lean being around .45v. The cross counts, ED18, is the rate at which the O2 signals the exhaust is crossing over this target between rich and lean. There is no set figure for cross counts but generally the higher number, the better. Single digit cross counts at hot idle and in the teens and more while driving indicates a good operating system. Just a suggestion, but an inexpensive infrared temperature gun might save toasted fingers when looking for an underperforming cylinder🙂 Getting to the rear exhaust would be an adventure but you are on to a good and useful means to narrow the search. You can also go into the override section of diagnostics and turn individual fuel injectors on and off to check for changes in idle quality. Sometimes it is helpful when doing a balance test to disconnect the IAC after a warm idle is achieved or the ECM will adjust idle speed to cover for a dropped cylinder.

I hope you meant ED07 when you typed ED08? Under what conditions were those readings taken? The engine must be warmed up and the exhaust hot to be sure the O2 sensor is active. If that is the case, then the ED08 should have been moving around constantly or the sensor is either dead or reading a very lean mixture. This can be caused by a misfire, which may read lean, or with both the fuel integrator and block learn maxed out, the ECM is adding as much fuel as possible. A misfire plus adding too much fuel will run very poorly. Check the fuel pressure just to rule that out. Just an outside chance and it does no harm: disconnect the MAF and see if it runs cleaner. If someone else pulled the plugs, does that include the rear ones? Unless done one at a time, and reconnected before moving on, it is quite easy to switch two of the rear ones, how well I know🙄

E044 is an O2 sensor code for lean. Have you checked the fuel pressure? What does diagnostic live data show for O2 sensor activity, ED07 (voltage) and ED18 (cross counts)? Related to this are the two fueling indicators ED19 Integrator or short term adjustment and ED20 Block Learn, long term fuel adjustment. Were the coil pack and ICM both replaced? If this is a spark issue you may have two cylinders out, that would be #3 and its mate, #6. Were plugs and spark plug cables checked for quality and is there any chance plug wires were crossed on assembly?

You can't go wrong purchasing from Jim. The 1990 is a one model year headlight switch. Maybe not related to your original reason for taking it apart but I highly recommend installing a headlight relay harness to take the headlight load from the switch.

Not true on the LN3. Maybe later model engines are not?

You can just eyeball it in the most basic way. Since everything that meshes together is curved, determining the spacing takes looking from every angle possible. The actual spacing isn’t that critical as long as nothing touches or rubs. A couple pieces of matchbook cover on either side of one vane will give reasonable proof the spacing is okay.

Only you can decide if it is worth the trouble to look into it further, but if both parts have been replaced, and they are generally reliable, there is something else going on. I do not know where the wiring for the cam sensor is routed on an '88 but if similar to an '89, it runs across the front under the radiator area. I had a cam sensor code on the '89 I purchased and found the wiring cut up front, maybe from being lifted or something but splicing them back together fixed the problem. When the sensor and magnet have been replaced, does the code go away, at least temporarily? Have you cleared the codes to see what returns? Just out of curiosity, if the cam interupter (magnet) was replaced by removing the front cover, did it also get a new timing chain and sprockets?

If you are familiar with LeSabre's of similar generation then it is exactly the same. Defects in the area mentioned do set any codes. Balancer and crank sensor behind it are best accessed through the wheelwell. Yes, the little shock and its mount must be removed to remove the balancer. If you have never removed the big bolt in the end of the crank, be prepared to apply lots of force. Torque spec is well over 200 lb/ft. Balancer itself is a slip fit and a puller is not needed. If the face of the balancer rubber has cracks or chunks missing, it is likely the source of the rattle at idle.

There are no caps for the end of the door pull straps. The end of the strap simply inserts behind the panel itself. If you pull the ends of the straps back toward the center of the strap, the two long fasteners will be revealed.

No, it is the harmonic damper on the front of the crank, not an unusual problem. Check for spark when it won’t start. Probably won’t have spark. What is your level of mechanical ability?

Typical items for loss of spark when hot is Ignition Control Module under the coils or the Crank Sensor. The crank sensor generally doesn’t heal when cooled off, it stays broken, but I had one that did so, so it can happen. Check the area between the coil pack and ICM for sticky or soft material oozing out. Sure sign it is failing

So much of the testing should be under load and heat that multimeter testing gives incomplete results. It is not useless, just not the full picture. Go to the Reatta Owners Journal site and look under diagnostics in the menu header and there is a link to the YouTube video of testing the module and coils

If they may have been original it could just be coincidence? I use Rock Auto parts a lot, but they usually have a selection of price, brand and possibly quality, in each category, so that is a pretty wide open choice without a pattern. The hi-po Walbro I have had in my '90 has been ticking along for over 20years and has been subject to race gas and experimental fuel additives over the years, not a steady diet, but hasn't missed a beat. If it needed replacement today it would probably get a turbine style from GM designed for one of the early supercharged cars.

Any particular brand or type of pump? I have never had such an issue with multiple brands of vehicles. Perhaps it is because my cars are almost always stored inside? Something odd about your gasoline?

The cam sensor may have a slight advantage in smoothness at low rpms, but unlikely to have any other discernible effect. Lots of engines have been produced without the sensor at all. The little brother of the 3800, the 3300 found in early '90's midsize cars like the Century, operates in batch fire mode and has no cam sensor. Rough figures: At 1000 rpm, the intake valve is only open an appreciable amount for 1/16 of a second every two revolutions, about 62 milliseconds total time. As demand increases from throttle input and rpm, the injector is open far longer than any possible intake valve opening so it is possible to time the fuel shot only at lower speed.

I am not familiar with the Reatta.net code reading instructions? Is it for shorting the aldl and reading flashes or is it to access the onboard diagnostics through the climate control head?? Is the check engine light indicating there are codes during normal driving??

Sounds like a good price on a good oil, and is appropriate for all of them. Now if you can just get fuel for all of them, life will be rosy.

3800’s into Fiero’s is a very common swap. Try GMTuners for some detail.

Well, I don’t know what change the timing might make, especially if not in a location with consistent temperature. The two interior air temperature, sun load and in car temp, are way in left field and would ignore them. A little sunshine through the glass would change things dramatically. It is interesting both the ecm and bcm report the exact same temperature, which makes sense if they are both reporting the single coolant temperature sensor. That leaves the underhood temperature in the air filter box MAT, the high and low side refrigerant and the ambient air temperature which are all within a four degree range. Not bad for over thirty year old sensors and would consider that a non issue. The coolant reading much cooler is sort of unusual, but I suspect as the day warms up, the coolant will lag behind the other temperatures under the hood? I would doubt these readings would have much effect on the AC performance but may want to check coolant temperature against a heat gun or actual thermometer.

I have never seen numbers quite like that? This is an '88, correct? I am not as familiar with the touchscreen so I am not certain about a blinking check engine light, but mine blinks when in diagnostic and closed loop. I will need to drive mine and see what mine does again, just for confirmation, but those numbers are extremely high. Ordinarily, that's a good thing, but seems out of range, and the dropping to zero shouldn't happen for extended periods. Almost seems as if dropping out of closed loop for some reason. What is coolant temperature indication? The previous comments about exhaust leaks and catalyst issues are certainly valid. Coasting downhill the forces on the drivetrain are somewhat reversed, engine vacuum is high and it is holding the car back to a small extent, less so in overdrive above about 50mph where there is almost no engine braking. Does it seem to vibrate more when idling or moving in reverse?

I don't think it has set long enough to equalize all the different areas of the car, and it must be a fairly warm area to be in the 70'sF at 3 am😎 I think any mileage change is purely coincidence.

If I understand, the engine shakes when not under load, like going downhill? The first thing I would do is watch the O2 sensor cross counts, ED18. It is the easiest way to get an idea if it is functioning properly. More cross counts is better. It needs to be warmed up and driving to get the best overall picture

Wabco STC 2784 Multiple sources online including eBay. This is a larger accumulator, equivalent to the Hydac, .33liter vs the .25liter standard. Usually requires adding a washer or two under the mount for the strut tower brace.

Does the CRT work? The module in the photo is definitely not the ECM and is called the information display module for the (CRT) for an '88, reman. If they are changing this module and the engine runs differently, something is very peculiar. Perhaps it is just coincidence and it simply runs better for a while until heat or vibration causes the issue to crop up? The ECM is located forward of the glove box, mounted vertically, with three large connectors on the bottom. Typically and engine that runs okay until warmed up that develops a misfire it is the coil pack and or ignition module below the pack. The ECM can also be subject to failure when hot. I suggest you or the mechanic visit the Reatta Owners Journal website and at the top of the page are links to diagnostics, repairs and a multitude of issues solved by actual owners over many years. Padgett mentioned the correct part numbers above.

Ahh, made the assumption it was ECM but I had the 1228253 number stuck in my head, so it looked wrong. I didn't know how wrong😣 Many of the same suggestions apply but shouldn't affect engine performance unless I am missing something? The underhood wash would be more likely, especially where harnesses connect or sensors plug in. Look hard at the ones concerned with the ignition, but anything that can be disconnected, checked for moisture and plugged back in would be in order.