2seater

What does the climate control screen look like in normal operation? Does it display fan speed, inside/outside temperature, air flow indicators etc..?

It would seem it is either the climate control or a BCM issue. The contacts in the climate panel is not uncommon but to stick part way into diagnostic is unusual.

The ECM energizes the fuel pump relay both for priming and for running. The prime we all know is to get enough fuel for the engine to start but when the ECM sees the pulsed signals from the ICM, it re-energizes the fuel pump relay. The switch in the oil pressure sender is a backup to the ECM control and connects directly to the fuel pump bypassing the relay.

Does it still fail to go past Ec? when you press Fan Up? You can read codes but not actual sensor data if that issue still exists.

Something doesn't look right here. The engine should not need to be running to get into diagnostic mode, only key on. But that is beside the point, since it appears the engine was running with indicated oil pressure and rpm visible, and yet the HVAC panel was blank and dark? I don't have my car home to confirm exactly what it should look like at the moment before getting into the ECM sensor displays. Can anyone confirm?? Regarding the cleaning of the HVAC panel. The contacts are inside the little gray buttons. It is similar to cleaning phone button pads or remotes for tv's and such. Everything runs on very low voltages so it doesn't take much. The most common failure mode of the buttons is the ability to raise or lower temperature, but even if it doesn't cure the problem, it eliminates one possible cause. The diagnostic displays are a function of the BCM.

If the HVAC panel is blank, there is more diagnostic information missing. Information is located in the HVAC panel as well as the buttons to change function. Something is amiss in that area. Oil pressure doesn't look too healthy for almost 2k rpm but the pressure sender is a known problem item.

Does the odometer reading work normally when not in diagnostics? That reading is a function of the BCM so ??? I was just looking at the photos again and I notice with the engine apparently running, the HVAC control panel is dark? It should be displaying something if ignition is on.

One other function that can't be accessed is the clear code function.

I cannot think of any reason your diagnostic system doesn't engage except the fan control button doesn't make good enough contact?? If that doesn't work, you are missing a lot of valuable and handy information. Maybe Padgett has a clue?

It should be less than one volt when closed but if the arm on the sensor has not engaged the drive pin on the throttle shaft correctly, it may be stuck at full voltage? If I am understanding correctly, you can access the diagnostics, since it shows an ECM code in the above photo, but the fan control doesn't work to get beyond the Ec? point, correct? That means you cannot step through the various sensor data readings??

It sounds like you could have two separate issues. If all the controls on the Climate Control panel do not work, it probably needs to be cleaned. The contacts inside get dirty over time and cleaning the contacts almost always restores functionality. See here Reatta Owners Journal - How To Clean 1990 Climate Control Panel Use the diagnostic function to read the TPS voltage. ED01 is the TPS and it should read .38-.42 volts at idle position and over 4.0 volts at full throttle. Of course the Climate panel must be operational to use the onboard systems. Edit: Codes that are active will not clear and the TPS needs to be adjusted when it is being installed.

That must be a BCM code, b132 is the oil pressure sender.

The pressure drop is normal as it references vacuum in the intake manifold. If you blip the throttle the pressure should spike upwards in response. 042 is the code for poor communication between the ECM and ICM. The ECM tries to take over the operational ignition timing after the engine starts and there is a problem with that. On a 1990 there is a short harness on the front of the engine that connects the ICM to a connection on top of the engine behind the power steering pump. Disconnect and examine the plug at the ICM looking for corrosion or backed out pins. Hopefully just removing, contact cleaner spray and reassembly may help. Same for the plugs on the ECM, specifically the black 32 pin one. The diagnostic chart is page 8D52 and 8D53 of the FSM.

I have never removed the transaxle on a Reatta, but I have removed the engine numerous times. Once the two items are separated, the torque converter simply slides out of the transaxle bellhousing. It is not fastened in any way but the drive notches (dogs) must be engaged inside the transaxle before bolting the two items back together. There are no new seals or fittings required regarding the torque converter itself. The three torque converter to flex plate fastener bolts are the first thing removed and the last thing installed.

I have no issue with the Allante mixed in here.

I would check with Jim Finn to see about a complete replacement line. There are three plastic lines connected to the fuel tank, 3/8"fuel pressure line, 5/16" fuel return and 1/4" vapor line to the charcoal cannister. Fabricating your own line seems pretty similar to patching it, but it is unusual to get "knicks" in the plastic line?? My $.02

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Opinion only, but I kept mine R12 when I replaced the compressor, (leaking oil). It still had some charge and worked minimally, so I didn't have quite the same dilemma you do. I was able to find a local shop that still had the equipment to recycle R12 but that is getting harder to do. Yes, R12 costs more, but, it isn't like the quantity needed is vast, especially if factored against the other changes required for 134a. I purchased all my parts from Rock Auto, compressor, condenser, accumulator and the correct oil and an o-ring kit. I would think the system will need to be flushed at the very least due to the mismatched fluids used. As long as the system will hold a deep vacuum for an extended period it can be refilled with R12. The shops I know won't do so unless the system is sound, as it should be, since that is illegal.

Correction to previous; yes the year is in the title😞 This sounds similar to what happened with Daves, ironically also an 88, when the crank sensor was loose in the bracket. Terrible behavior but not a constant.

You didn't mention what year Reatta, but do you know how to access the onboard diagnostics? Is the check engine light on?? Is the ICM and coil pack new or salvage yard and is it the correct package? I know that may be a silly question but there are similar setups for some other GM V6's that may not function correctly.

Well, as one person that has spent too much time, and money, on an obsolete engine, I can relate🙄

I agree. I know I am veering off the original purpose of this thread, but for the apparent amount of work involved in shoe horning a 3800 into a Cavalier, you can supercharge or turbocharge the original. Of course, if the original is worn out, that does change the equation some, but the major fitup work is already done.

I thought about relocating the fwd drivetrain to the rear, similar to Fiero. Space wise, there is enough room. The video is a fwd transplant? It looks like it will have some peripheral and accessory stuff to work out. I imagine the engine and trans were bolted together for fit up only. If he can’t get it to fit, no sense working out a clutch arrangement🤔

I am certainly not an authority, but I am pretty certain the 200R4 from the Grand National 3.8's is a BOP bolt pattern, which is not compatible with the 60deg V6 pattern used on the fwd 3800. While the 3.8 is the predecessor to the 3800, they are not the same aside from displacement. I grabbed the info below from Wikipedia. According to this, the 3800 in a rwd Camaro has the starter on the opposite side so is the rwd transmission compatible with the fwd engine is an unanswered question. There are some interesting or unexpected vehicles on the list below. One item I often wondered about and that was why no one has done the LS4 into a Reatta? I found, from Ryan at GM Tuners, that part of the shortening process to create the LS4 relocated the starter to the transmission bellhousing, making it incompatible with our transaxle. Rumor is that the trans. from an S10 with a V6 will work???? GM metric pattern[edit] Also called the GM small corporate pattern and the S10 pattern This pattern has a distinctive odd-sided hexagonal shape. Rear wheel drive applications have the starter mounted on the right side of the block (when viewed from the flywheel) and on the opposite side of the block compared to front wheel drive installations. The 2.2l S10/Sonoma had the starter located in the same position as front wheel drive cars. A rear wheel drive bellhousing is displayed at right, and the integrated front wheel drive bellhousing is displayed at the lower right (in this case, as a part of the GM 6T70 Transmission). GM 60-Degree 2.8/3.1/3.4/3.5/3.9 L V6 (also used by AMC) Buick 3300/3800 V6 Cadillac HT4100/4.5/4.9 L V8 Isuzu all 3.2 and 3.5L DOHC V6 AMC/Chrysler 2.5L I4 found in Jeep Cherokee, Comanche, Wagoneer, CJ and Wrangler and Dodge Dakota GM Iron Duke/Tech-4 2.5L I4 GM "122" 1.8/2.0/2.2 L I4 GM 5.3L LS4 V8 GM High Value engine

Well, the 3800 does have the same bellhousing bolt pattern, which is the 60deg V6 pattern, so would likely be similar to the swap into a Fiero, but it is a fairly tall and wide engine. Being a 90deg V6 with a ~9.5" deck height, it has about the same cross section as a 351 Ford engine. A Series 2 3800 is more compact but that doesn't help the using the original problem.