2seater Posted January 27, 2023 Share Posted January 27, 2023 Do you know how to access the diagnostics? My suspicion is the engine is going into limp mode when the rpm indicator disappears. First it will give you existing trouble codes, and second, you can watch pretty much all the relevant sensors while it is running from the comfort of the drivers seat. Link to comment Share on other sites More sharing options...
jg2003 Posted January 28, 2023 Topic Author Share Posted January 28, 2023 18 hours ago, 2seater said: Do you know how to access the diagnostics? My suspicion is the engine is going into limp mode when the rpm indicator disappears. First it will give you existing trouble codes, and second, you can watch pretty much all the relevant sensors while it is running from the comfort of the drivers seat. Only code I got that wasn't a history one was E041C y'all don't happen to know what that might be?. Link to comment Share on other sites More sharing options...
rogold Posted January 28, 2023 Share Posted January 28, 2023 ECM Diagnostic Code Chart - Reatta Owners Journal Link to comment Share on other sites More sharing options...
Padgett Posted January 28, 2023 Share Posted January 28, 2023 See here. Link to comment Share on other sites More sharing options...
Ronnie Posted January 28, 2023 Share Posted January 28, 2023 1 hour ago, jg2003 said: Only code I got that wasn't a history one was E041C y'all don't happen to know what that might be?. Code E041 is cam sensor. Usually you don't see a noticeable difference in performance. Engine should start and run without problems. Gas mileage might be slightly lower. 1991 models might be different. Link to comment Share on other sites More sharing options...
jg2003 Posted January 29, 2023 Topic Author Share Posted January 29, 2023 22 hours ago, Ronnie said: Code E041 is cam sensor. Usually you don't see a noticeable difference in performance. Engine should start and run without problems. Gas mileage might be slightly lower. 1991 models might be different. Do you guys think it might be the cam magnet it has 60,000 miles on it and was sitting for a couple of years do you guys think it wore off?? Or could it be a simple replacement of the sensor itself? Link to comment Share on other sites More sharing options...
Ronnie Posted January 29, 2023 Share Posted January 29, 2023 Usually the problem is the magnet that triggers the sensor. It doesn't wear out. The plastic that encases the 4 magnetic rods gets old and breaks allowing the magnets to fall out. Padgett has an documented an easy fix (in the menu above) that can be done without taking the engine apart. If I were you I would focus on getting the engine running properly and save the cam magnet for later. Thanks to Padgett for the photo. Link to comment Share on other sites More sharing options...
jg2003 Posted January 29, 2023 Topic Author Share Posted January 29, 2023 (edited) Okay guys so drove it around the block for a bit and yepp it's going into limp mode significant loss of power car struggled to get into the driveway. Any suggestions on where to start looking? I'm having a recurring issue where dash shows no rpm and the car doesn't have much power. But when it was displaying rpm and mph it was driving fine and felt like it had power. Also did an oil change and the car seems to start up at first crank now. Edited January 29, 2023 by jg2003 Link to comment Share on other sites More sharing options...
Padgett Posted January 29, 2023 Share Posted January 29, 2023 Should have set a code but may be in history (h) and not current (c) Did you look at my web page ? Lost the magnet in 2002/about 50k and replacement is still working. Link to comment Share on other sites More sharing options...
jg2003 Posted January 30, 2023 Topic Author Share Posted January 30, 2023 GOOD NEWS it runs no issues so far drove 20 minutes around nearby roads didn't stop or do anything weird. We got around to doing basic maintenance like an oil change, checking the filters, and whatnot. The oil change helped it start at first crank but still had that weird limp mode. Dad had bought some Lucas injector cleaner we put it in and had it idling and boom fixed the issue it doesn't go into limp mode anymore and the car was accelerating and driving no issues. Now we need to checkout the code y'all were helping me out with. Plus need to fix the headliner and some new tires I'll post pictures once I can get the car cleaned up. Thank you guys for being willing to help me out learned a lot about cars in one week haha. I hope to be able to contribute and I'll for sure be back with questions in the future thank y'all. Link to comment Share on other sites More sharing options...
2seater Posted January 30, 2023 Share Posted January 30, 2023 I was going to ask how you determined it was in the limp mode, which is generally indicated by reduced timing and perhaps richer fueling but it sounds like you have a fuel system that needs some TLC. I am glad it is behaving better. Link to comment Share on other sites More sharing options...
Ronnie Posted January 30, 2023 Share Posted January 30, 2023 1 hour ago, jg2003 said: The oil change helped it start at first crank I'll have to remember that. If mine gets hard to start, I'll change the oil. Glad to hear you are getting it straightened out. I'm sure you will enjoy it when you get it running as it should. Link to comment Share on other sites More sharing options...
2seater Posted January 31, 2023 Share Posted January 31, 2023 Another not directly related item but I made a comment about limp mode and it is actually "module mode" in GM speak. Code 042 would be one way for this to occur but I believe there are others. It is the normal mode the ICM is in to start the engine ignition independent of the ECM. It is a fixed timing of 10deg advance if the ECM ignition timing signal to the ICM is somehow lost or shorted to ground. Link to comment Share on other sites More sharing options...
jg2003 Posted February 5, 2023 Topic Author Share Posted February 5, 2023 (edited) On 1/31/2023 at 4:22 PM, 2seater said: Another not directly related item but I made a comment about limp mode and it is actually "module mode" in GM speak. Code 042 would be one way for this to occur but I believe there are others. It is the normal mode the ICM is in to start the engine ignition independent of the ECM. It is a fixed timing of 10deg advance if the ECM ignition timing signal to the ICM is somehow lost or shorted to ground. Welp it very well might be an icm issue a negative update for everyone. Car was good if sluggish for like 3 days. As you may or may not know a light freeze came to Texas. Well temperature dropped to 35 degrees car hated it and decided it didn't want to get out of bed like me. Refused to start at all and now won't start without gas input then it'll stall and sputter. Now it's starting but running rich and it goes without rpm reading and revs high fans come on too. Now it's starting but running like shit weather went up to 56. Anyone have a guess at what might be causing the issue. I saw some people said these were symptoms to bad ignition stuff like coil packs or something. Sunday I'm going to do the fuel pressure test. And I'm going to check the ignition packs and while I'm at the icm any tips on what to look for in the icm. And anything to look into overall? My uncle's mechanic friend thinks the catalytic converter is bad cause there was a lot of heat in the rear of engine y'all think that might be it? He also pointed out the mass airflow sensor as a possible issue car was kinda bogged when he messed with the airflow. It doesn't look to dirty AutoZone says 100 for an OEM one might just use alcohol. Also car went into to gear while in idle and it died. Edited February 5, 2023 by jg2003 Link to comment Share on other sites More sharing options...
jg2003 Posted February 5, 2023 Topic Author Share Posted February 5, 2023 Okay overnight we managed to get it going starts but has issues. As the car was let idle it started to behave better and was able to shift gears no issue. I recently checked fuel pressure and when I did the test it was at 40 psi. The issue of rpm disappearing and the car idling at high rpm/fan activating also persists. As we examined the car the Idea of the Mass airflow sensor being bad was brought about we took the sensor off and had it idle it stumbled and then after letting the car idle longer it became smoother. This morning we cleaned the sensor with alcohol and again tried it on no issue took it of and again no issue. The mechanic thought the car might just need to clean its fuel system. We put some octane booster in and it helped. Took it on a drive going constant 30mph for about 15 minutes I noticed that the car lacked acceleration and was just sluggish. On the way home the car marked low oil and shut off. Tried to start it normally cranked but no go then pressed the gas pedal while starting and was able to drive it back home. I am going to go ahead and replace the fuel filter anything else I should look into?. Link to comment Share on other sites More sharing options...
Padgett Posted February 6, 2023 Share Posted February 6, 2023 a: "marked low oil and shut off." it is supposed to b: MAF: ED021 is air flow (what the MAF measres) See the 88-89 diagnostics booklet above. Link to comment Share on other sites More sharing options...
2seater Posted February 6, 2023 Share Posted February 6, 2023 Did you get into diagnostics and see what the indicated ignition timing was? The fuel pressure sounds about right but a bit more detail about the conditions under which it was obtained would be helpful. Normally the IAC, idle air control, will supply enough air to start the engine without touching the throttle, but I get the impression you needed to open the throttle a bit to get it to start and run? Did the MAF sensor look like the one on the right or left in this photo. A 1991 should use the model on the right, but either style will bolt on. 1 Link to comment Share on other sites More sharing options...
Ronnie Posted February 6, 2023 Share Posted February 6, 2023 Quote Posted January 28 On 1/28/2023 at 1:03 PM, jg2003 said: Only code I got that wasn't a history one was E041C y'all don't happen to know what that might be?. Code E041 is cam sensor. Usually you don't see a noticeable difference in performance. Engine should start and run without problems. Gas mileage might be slightly lower. 1991 models might be different. I wonder if a code E041 has a bigger effect on performance in '91 models than it does in other models? I always make statements like the one above without thinking that the '91 models might be controlled differently. Maybe that statement was wrong and the code 41 is causing the problem. Anybody know? Link to comment Share on other sites More sharing options...
2seater Posted February 6, 2023 Share Posted February 6, 2023 8 hours ago, Ronnie said: I wonder if a code E041 has a bigger effect on performance in '91 models than it does in other models? I always make statements like the one above without thinking that the '91 models might be controlled differently. Maybe that statement was wrong and the code 41 is causing the problem. Anybody know? I cannot say with 100% certainty, but since the ignition coils and ICM are completely interchangeable with the Magnavox, odds are there is no difference. The cam sensor inputs its signal to the ICM. The clues about losing the tachometer and some other apparent gremlins may be a wiring issue, or a bad connections? Link to comment Share on other sites More sharing options...
2seater Posted February 6, 2023 Share Posted February 6, 2023 One other item I know I have mentioned before and discovered by accident, and that is hidden damage to the wiring inside the small front engine harness of the 90/91. This harness connects the ICM to the Crank,Cam and Knock sensors as well as plugging in to the main harness behind the power steering pump. Link to comment Share on other sites More sharing options...
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