rgi82

I forgot to mention that after it was purring nicely at 950 RPMs, the moment I increase RPMs with the accelerator, it starts running very roughly and uneven and labors to get up to higher RPMs. It will eventually get up to the higher RPMs (4500) but it is not smooth - it's rough and the exhaust pops and sputters.

Hello again, Here are a few more observations: the fans for the radiator will immediately come on when the ignition is in the "on" position and stay running even though the engine is cold and not running. When the engine is turned on, and is still cold, the fans continue to run even though the temp is no where near 100. when the engine is initially started, it runs rough and labors to keep running turning at about 600 RPM and eventually gets up to 800 RPM...but still laboring to keep running; and I am not touching the accelerator at all. During this time, the CEL is on but is intermittently dimming and blinking out momentarily before becoming brightly illuminated again. Then, about 3-4 minutes later, all by itself, it gets up tro 950 RPM and is purring smoothly with no misfires, pops, or smoke in the exhaust...yet the CEL is still illuminated...this time with no blinks or dimming. I uploaded the Freescan program again into the laptop and connected it to the forward glovebox ALDL connector and it still did not receive data. I installed a driver for the program which ran out of COM 6 and noted that the "Bytes Sent" and "Bytes Received" continued to read 0 after clicking "start" in the "Communications with ECU" box. This was the case with both "listen" and "Interact" modes. I did note that when I pulled the USB connector out of the computer, a window popped-up indicating that an abnormal disconnection had occurred. I'm leaning toward the ECM being the problem but would welcome any other opinions and recommendations. Thanks. Romero

Hello all, Thanks for your suggestions so far...sadly though, no joy yet - engine still misfires. So this is what I have done/learned: I found the 3 grounding wires that originate from the ECM and terminate on top of the transmission casing - removed the bolt, washer, and wire rings...wire brushed and filed all contact surfaces and sprayed with Lectra-Motive electrical part cleaner and re-installed. No change...engine still misfires. I disconnected all 4 wire harnesses from the ECM. Conducted continuity check on the orange wire (serial data) from the J2B(red) connector harness which leads to the two ALDL connectors and discovered: continuity exists to the forward (glove compartment) connector at the "G" port. no continuity to the aft (trunk) connector at the "G" port. I then verified that all the other pins in the forward (glove compartment) ALDL connector were functional: continuity on the white/black wire from the J2B(red) connector harness to the "B" port. +12 Volts on the purple wire of the "F" port; and +12 Volts at the ECM fuse between the ALDL and the ECM connector harness. ground continuity on the "A" port. I sprayed Lectra-Motive into the ports of the four ECM harnesses, let them drip out and then reconnected all the harness while wiggling the connectors. I also disconnected all the connectors and spark plug leads from the ignition modules and high tension coils and then wiggled them as I reconnected them; as well as the connectors for the: throttle position indicator MAT sensor Verified all fuses are intact and functional Noted equal level of carbon build-up on all spark plugs - replaced all spark plugs These were my observations when the engine was running after I accomplished all the above: At start-up, the engine would run rough and hoover around 700 RPM. After slowly revving the engine up to 2200 RPM and maintaining it at that level, the engine continued to run rough with a noticeable imbalance of power to the crankshaft. When returning to idle, the engine ran at 950 RPM and was completely smooth - no imbalance of power, no popping and no smoke in the exhaust; however, the CEL stayed illuminated. When revving to higher RPMs (2200 - 3000), the CEL would dim and flicker off for brief moments and then come back on (fully illuminated) and it would continue this behavior until I brought it back to idle (950) where the engine would again run smoothly but the CEL stayed on (brightly) with no flickering. The car is 35 years old and has 187,000 miles on it (yes, that number is correct...I'm the original owner). It used to be my daily driver when I was working and now that I'm retired, I take it to the track often...most recently, Watkins Glen. Would it be safe to say that the ECM has gotten too tired to work properly at this point in its life or is this there anything else I can check? I really hate the fact that I still can't get diagnostic codes to read. Thanks again for any suggestions you may have. Romero For Tomcattom, where did you get your "AC Delco Professional" branded replacement ECM? Romero

Hello all again, I am unable to read any codes from ECM. I've tried both the engine compartment and the "behind the glove compartment" ALDL connectors using the "paperclip ion slots A and B" method and confirmed that slot A has continuity to ground; and the CEL just stays illuminated...it doesn't blink a code. Does anyone know what I should check to get the ECM to blink the CEL when slots A and B are connected? I have also read the other topics regarding Freescan connection problems and have tried them, but I still have no data coming into the Freescan program. I suspect that for some reason, the ECM is not sending data down the orange wire of the ALDL connector even though it still causes the CEL to illuminate. Any ideas would be most welcome....thanks. Romero

Hello all, my 1990 Esprit SE was garaged for about 6 months and when I took it out a month ago, everything worked perfectly fine. I have driven it intermittently since then and then 2 days ago when I picked-up the car from an auto-body shop, the engine began to run roughly and the CEL was blinking erratically (very dim and then off and then dim) while the engine was running roughly. The car was at an auto-body shop have work done on the front bumper where they did not go into the engine compartment and did not disconnect the battery, but they did take it to a car wash to have it cleaned after which the shop's driver noted the CEL flashing. After noting that the problem still persisted increasing RPMs, I disconnected the battery and then reconnected it to see if resetting the engine settings would resolve the problem...it did not. I noted though that after this action, the car idled perfectly smooth at 950, but the CEL was still on and would start to run rough when I increased the engine RPMs. I decided to drive it off the lot and after a few minutes, it ran perfectly fine and the CEL went out. I drove at 35 MPH for a long stretch in 3rd gear to let the ECM relearn its settings and then took it onto the parkway where I had it up to 70 mph without any problems. I was thinking that perhaps some water got sprayed into the engine compartment at the car wash and had initially caused the problem but had now evaporated. As I approached home and was driving slower however, the CEL came on again along with the rough running engine. I was troubleshooting today and CEL is still on and the engine still runs rough and it appears that it was running rich as the exhaust fumes were initially dark and noticeable coming out of the tailpipe. Interestingly, after idling for awhile, the engine began to run very smoothly at idle (950 RPMs) and the exhaust was now normal and not apparent. If I increase RPMs however, it will run roughly as I increase it and become less rough as I maintain a steady (albeit higher) RPM...I went up to and maintained 4200 RPMs with some popping noise. I tried to read the diagnostic codes by running a paperclip from slot A to slot B in the engine compartment ALDL connector, but the CEL just stays on when I turn the ignition to the "on" position....it doesn't blink. I verified that the ground wire of slot A is grounded by doing a continuity test between the slot and the engine. I also have the Freescan program in a laptop and when I connect it to the ALDL connector in the compartment, no input data is detected by the program. Please provide any advice on: 1) what could be causing the CEL to not blink the trouble codes when connecting slots A and B of the ALDL. 2) how I can get the Freescan program to receive the ECM data 3) what could be the root cause of the aberrant engine behavior. Many thanks, Romero

Hello Ian, Thanks for the feedback…I'm at the point of disassembling the exhaust system aft of the turbo…we'll see what's found….

Hello all, I took the air filter assembly off as well as the air trunk the connects to the turbo intake and noted no obstructions with the intake system although I noted the air filter probably needs replacement. Additionally, I was able to turn the compressor end of the turbo rotor pretty easily with my fingers and noted that it rotated smoothly with no abnormal sounds (e.g. grinding or clanking). I suppose that now leaves the exhaust system downstream from the turbo to be evaluated. As I thought about this further, I realized that two other things occurred that may have a bearing on my situation: four years ago, an injector malfunctioned which caused the engine to run very roughly. I disabled the other associated injector so that I was able to limp home with the engine running a little smoother but I suspect that I wound-up with a muffler fire as the muffler was extremely hot - so hot that it caused the fiberglass of the rear bumper to heat-up and start melting to the point where I could smell fiberglass vapors. After I replaced all 4 injectors, the car ran normally which included the routine boost acceleration from a properly functioning turbo. two years ago, my Cat detached at the collar of the flange that attaches to the turbo during a "spirited" run. I had it welded and then I cleaned-out the honeycombs in the Cat of debris and ensured good air movement though it using the discharge section of a vacuum cleaner before installing it. The car performed perfectly as it had before until a month ago when the above noted behaviors occurred. As I think about it, the manner in which the exhaust gasses come out of the tail pipe seems different - not as forceful. Does anyone have a suggestion on how I can test the exhaust system to see if the necessary flow capacity is present? Also, how long should a Cat last?…the car is 25 years old and I've driven it as my everyday car all those years and have 146K+ miles…thanks. Romero

Hello Bibs, Jim and Travis, Thank you for the suggestions. I've ordered the connector wires and will conduct a scan after they are delivered. Also, I checked all the air hoses that emanate from the turbo unit including the plenum connector and all are properly connected and have no rips/tears/holes. The Exhaust back pressure valve has been disconnected from the vacuum line and the valve is wired to the "open" position. With your suggestion, I had hoped that the wire had broken and the valve was the source of the problem; unfortunately, that wasn't the case…the valve is still locked open. I'll take a look at the air intake system this weekend. Regarding the "boost" gauge needle, it doesn't move…it stays pegged left at 0 with only the slightest little movement to the right (barely off the 0 line) as noted earlier. I recall in some of the other entries that inadequate fuel pressure caused others to have problems with their boost capability. Do you think the symptoms that I'm experiencing could be caused by inadequate fuel line pressure? If so, how should I go about testing for this possible cause? If my turbo rotor is froze, or spinning too slowly, how could I check for this?…and if this is the situation, do I have any options to salvage the turbo? Thanks again for your time and advice. Romero

Hello Bibs, Thanks…I tried to download the Freescan (v.2.1.0) but was unsuccessful…I suspect that the Apple computer I'm using is not compatible. Is there an Apple compatible variant available?

Hello all, Here's updated observations once I removed the wastegate control valve capsule: - the capsule appears to be working properly because when I took it to my bench and used a hand-pump with a better fitting, the capsule arm moved to an extended position and maintained that position until I allowed the air pressure to escape from the fitting. - the hoses that connect to the wastegate control valve capsule and the pressurized air plenum did not leak either when put under 20 pounds of air pressure…the lines maintained the pressure each time - having applied the pressure from the different ends. - one other observation that I forgot to mention earlier is that I did detect a very slight movement (barely above the 0) on the boost gauge when the engine initially reached normal operating temp (80 C) when I floored the accelerator (at 3000 RPM) - but it didn't translate to any discernible acceleration. I repeated this a couple of times and noted that as I continued to drive, the boost gauge needle wouldn't move at all. Thanks again for any ideas and/or assistance you may have to offer. Romero

Hello all, I would be very grateful for any assistance that you could provide. I have a turbo boost problem with my '90 Esprit SE which has just appeared for the first time…I do not see any boost indications nor do I feel the normal significant acceleration that typically occurs at 2800 RPM…and I do not hear the turbine wind-up any more either. Having read other threads from others experiencing turbine problems and the trouble-shooting recommendations that were provided, I have made the following observations: - engine temp settles to a little over 80 C when at freeway speed but runs hot at slower speed (close to 100) which requires the fans to engage - I suspect this symptom is more a function of a degraded (inhibited air flow) radiator given that I have over 146,000 miles on her. - engine behaves normally (minus the missing boost capability) both in actual driving and when idling although when trouble-shooting, I noted that the check engine light illuminated when reaching 4500 RPM (no actual load on engine - was in neutral and parked). - after applying air pressure into the end of the pressure sensing hose at the point it connects to the turbine outlet, the wastegate control capsule did move to open the wastegate flap valve; however, the wastegate flap valve moved back to the closed position within a few seconds. I didn't hear/notice any air leaks in the hoses. I believe that the valve was supposed to maintain its open position rather than return to the closed position. Questions: - Would a degraded diaphragm in the capsule cause the above noted symptoms? - If the diaphragm is the source of the problem, where can I buy a replacement and is there anything else I should get?…and are there any special procedures I should be aware of when replacing it. - If it's not the diaphragm, what else should I look for? Thanks…and I look forward to your assistance on this. Romero