stevenM Posted July 23, 2005 Report Share Posted July 23, 2005 I have a 1993 Eldorado Sport 4.6L. The car is having problems with fuel load up. I have replaced the following. Map Sensor O2 Sensor Fuel Pressure Regulator TP Sensor TP Switch Ignition Module Spark Plugs Checked and Cleaned Injectors Checked Injector Drivers- It Seems They Are Open All The Time... I Have Tried Using Three Different PCM's I start the car and it belches out black smoke. It clears when at high RPM, and loads up at lower RPM. It sucks up gas so fast I can't beleive it! Is it possible the injectors are staying open all the time, and if so would it do it with three different PCM's? Stumped in Denver Link to comment Share on other sites More sharing options...
TDK Posted July 23, 2005 Report Share Posted July 23, 2005 StevenM, Do the injectors leak fuel when the ignition is on, but the engine is not running? How did you actually "clean" the injectors? I though they were simply a replacable part (not a user serviceable part) What do you mean by "Injector Drivers"? WHOOPS! Sorry I first missed your part about the FPR being replaced already (was it new)? The following was submitted incorrectly... ***************************** Have you checked the Fuel Pressure Regulator (FPR)? As I understand, if it fails it can have fuel come out the vac side, which will be drawn into the engine uncontrolled. You may have been lucky to not hydrolock a given cylinder and blow the engine by pouring fuel in. Don't start it up, but disconnect the vac hose from the FPR, turn the ignition on. If it leaks fuel out the vac connection - replace it. Good luck ! Add power to leave problems behind. Most braking is just - poor planning. Link to comment Share on other sites More sharing options...
stevenM Posted July 23, 2005 Author Report Share Posted July 23, 2005 StevenM,Do the injectors leak fuel when the ignition is on, but the engine is not running? How did you actually "clean" the injectors? I though they were simply a replacable part (not a user serviceable part) What do you mean by "Injector Drivers"? WHOOPS! Sorry I first missed your part about the FPR being replaced already (was it new)? The following was submitted incorrectly... ***************************** Have you checked the Fuel Pressure Regulator (FPR)? As I understand, if it fails it can have fuel come out the vac side, which will be drawn into the engine uncontrolled. You may have been lucky to not hydrolock a given cylinder and blow the engine by pouring fuel in. Don't start it up, but disconnect the vac hose from the FPR, turn the ignition on. If it leaks fuel out the vac connection - replace it. Good luck ! I tested and clead the injectors by removing them from the car. I ran carb cleaner through them to make sure they didn't have anything causing them to stick. I used a battery recharger to activate them and make sure they were opening and closing. I then bench tested them and they were all in spec.. Then I hooked up a blood pressure bulb and made sure they were not leaking under pressure. I tested the injector drivers (wire Plugs to injector) by using a voltage meter and turned the engine over. Ideas? Link to comment Share on other sites More sharing options...
KevinW Posted July 23, 2005 Report Share Posted July 23, 2005 Have you inspected for fuel rail or regulator leaks while the system was pressurised (intake manifold cover removed - remember not to start the engine)? How do the spark plugs look? ___________________________________________________ Link to comment Share on other sites More sharing options...
stevenM Posted July 23, 2005 Author Report Share Posted July 23, 2005 Have you inspected for fuel rail or regulator leaks while the system was pressurised (intake manifold cover removed - remember not to start the engine)? How do the spark plugs look? The fuel rail and regulator seem to work fine. The plugs are black from the carbon. When the car is running the smoke smells of gas. This is a 55k mile engine. I feel that this must be an electrical problem that I am missing. Link to comment Share on other sites More sharing options...
KevinW Posted July 23, 2005 Report Share Posted July 23, 2005 I assume that all 8 plugs are equally black? Are any diagnostic trouble codes being reported by the PCM? While in diagnostic mode, have you reviewed all the engine-related parameters for 'reasonable' data? A poor ground connection might skew one or more PCM inputs. For example, an incorrect MAP input could force an over-fueling condition at idle, but might not be extreme enough to trigger a DTC. It is important to see what the PCM is 'seeing'. ___________________________________________________ Link to comment Share on other sites More sharing options...
stevenM Posted July 23, 2005 Author Report Share Posted July 23, 2005 I assume that all 8 plugs are equally black? Are any diagnostic trouble codes being reported by the PCM? While in diagnostic mode, have you reviewed all the engine-related parameters for 'reasonable' data? A poor ground connection might skew one or more PCM inputs. For example, an incorrect MAP input could force an over-fueling condition at idle, but might not be extreme enough to trigger a DTC. It is important to see what the PCM is 'seeing'. Yes, all eight plugs are equally black. There are not any current codes. I have looked at all the data. I am not sure how I can see what the PCM sees except for the codes? That is why this is such a mystery. Link to comment Share on other sites More sharing options...
MAC Posted July 23, 2005 Report Share Posted July 23, 2005 When you say the fuel rail is fine, does this mean you took the cover off and checked for leaks? I just fixed a nasty fuel rail leak caused by a bad o-ring. The fuel regulator was fine but the o-ring allowed fuel to fill up the intake. I suggest if you haven’t already done so, that you run the car, shut down, and immediately take the cover off and check for leaks. Link to comment Share on other sites More sharing options...
KevinW Posted July 23, 2005 Report Share Posted July 23, 2005 Under "PCM DATA", what is the value for parameter PD02 (MAP)? BTW, have you checked the fuel pressure? ___________________________________________________ Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 When you say the fuel rail is fine, does this mean you took the cover off and checked for leaks? I just fixed a nasty fuel rail leak caused by a bad o-ring. The fuel regulator was fine but the o-ring allowed fuel to fill up the intake. I suggest if you haven’t already done so, that you run the car, shut down, and immediately take the cover off and check for leaks. The problem lies beyond the fuel rail. The engine will run great as soon as I can figure out the reason for so much gas to be dumped into the cylinder. As I said before, when I checked the injector drivers they all stay hot while the engine was turned over but not started. Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 Under "PCM DATA", what is the value for parameter PD02 (MAP)? BTW, have you checked the fuel pressure? How would I get into "PCM DATA", and what is the proper reading. The fuel pressure is in the normal range. However, when the key is turned off the pressure almost emediateley drops to zero. Link to comment Share on other sites More sharing options...
Ranger Posted July 24, 2005 Report Share Posted July 24, 2005 when the key is turned off the pressure almost emediateley drops to zero. Bad check valve at the pump. Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 when the key is turned off the pressure almost emediateley drops to zero. Bad check valve at the pump. Bad check valve? Would this cause the car to flood? Link to comment Share on other sites More sharing options...
KevinW Posted July 24, 2005 Report Share Posted July 24, 2005 I suggest consulting the FAQ on this site for information on the entering diagnostic mode. http://www.caddyinfo.com/howto.html What method did you use to check the injector drivers? The engine would never run if all the injectors were at 100% duty cycle. ___________________________________________________ Link to comment Share on other sites More sharing options...
Ranger Posted July 24, 2005 Report Share Posted July 24, 2005 when the key is turned off the pressure almost emediateley drops to zero. Bad check valve at the pump. Bad check valve? Would this cause the car to flood? I am not 100% sure, but it would account for the pressure drop right after key off. Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 I suggest consulting the FAQ on this site for information on the entering diagnostic mode. http://www.caddyinfo.com/howto.htmlWhat method did you use to check the injector drivers? The engine would never run if all the injectors were at 100% duty cycle. I checked the drivers with a voltage meter not a noid light. As you say the engine would never run at 100% full duty. However, you would not beleive how much gas it can suck down in just minutes. Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 I suggest consulting the FAQ on this site for information on the entering diagnostic mode. http://www.caddyinfo.com/howto.htmlWhat method did you use to check the injector drivers? The engine would never run if all the injectors were at 100% duty cycle. Is there a way to test the PCM? Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 I suggest consulting the FAQ on this site for information on the entering diagnostic mode. http://www.caddyinfo.com/howto.htmlWhat method did you use to check the injector drivers? The engine would never run if all the injectors were at 100% duty cycle. Is there a way to test the PCM? Is there a way to lean out the fuel system, or is it set by the PCM? Link to comment Share on other sites More sharing options...
KevinW Posted July 24, 2005 Report Share Posted July 24, 2005 Is there a way to test the PCM?Is there a way to lean out the fuel system, or is it set by the PCM? The probability of all 8 injector drivers or the fuel calibration 'changing' in such a way that it affects fueling in the way you describe is probably in the order of winning the lottery jackpot 3 times in a row! Wouldn't the 3 PCM replacements rule-out the PCM itself? If the Memcal failed the checksum (i.e. one or more bits of data were changed), a DTC would be reported or the PCM would go 'dead'. I believe there's a fail-safe mode, which might contribute to richer than normal operation, in the event of a major electronics failure, but this should be immediately apparent when entering (or attempting to enter) Diagnostic Mode. The fuel calibration is determined by software code and reference tables, contained mostly on the aforementioned Memcal, or what some refer to as a 'chip'. It is possible to modify the fueling characteristics, but why would assume the calibration has changed? The PCM pulls the individual injector circuits down for a very short period of time; I don't know how one would use a voltmeter to verify properly their operation. How did you determine that no DTCs are current? Have you reviewed the FAQ link on how to enter Diagnostic Mode? ___________________________________________________ Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 Is there a way to test the PCM?Is there a way to lean out the fuel system, or is it set by the PCM? The probability of all 8 injector drivers or the fuel calibration 'changing' in such a way that it affects fueling in the way you describe is probably in the order of winning the lottery jackpot 3 times in a row! Wouldn't the 3 PCM replacements rule-out the PCM itself? If the Memcal failed the checksum (i.e. one or more bits of data were changed), a DTC would be reported or the PCM would go 'dead'. I believe there's a fail-safe mode, which might contribute to richer than normal operation, in the event of a major electronics failure, but this should be immediately apparent when entering (or attempting to enter) Diagnostic Mode. The fuel calibration is determined by software code and reference tables, contained mostly on the aforementioned Memcal, or what some refer to as a 'chip'. It is possible to modify the fueling characteristics, but why would assume the calibration has changed? The PCM pulls the individual injector circuits down for a very short period of time; I don't know how one would use a voltmeter to verify properly their operation. How did you determine that no DTCs are current? Have you reviewed the FAQ link on how to enter Diagnostic Mode? I know there are no current codes when I enter the diagnostic mode. I am at a loss as to what the problem could be. I talked with a local dealer and he too was stumped. I am trying to figure this out before taking it to the shop. It is a fuel problem, and I would think it could only be so many things. Link to comment Share on other sites More sharing options...
KevinW Posted July 24, 2005 Report Share Posted July 24, 2005 While in Diagnostic Mode, are you able to view the PCM Data parameters? Answer 'Yes' to the prompt "PCM DATA?". ___________________________________________________ Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 While in Diagnostic Mode, are you able to view the PCM Data parameters? Answer 'Yes' to the prompt "PCM DATA?". KevinW I was able to retrieve the PCM parameters. How do I find out if they fall in the normal operating range, and can it be reset in diagnostics? Link to comment Share on other sites More sharing options...
KevinW Posted July 24, 2005 Report Share Posted July 24, 2005 I was able to retrieve the PCM parameters. How do I find out if they fall in the normal operating range, and can it be reset in diagnostics? The factory service manual is an invaluable resource. You should be able to confirm the MAP reading by using a good vacuum gauge and a barometer. I already asked you to post the reading for parameter PD02; while you're at it, PD01-PD11 and PD36-39 might be useful too. ___________________________________________________ Link to comment Share on other sites More sharing options...
stevenM Posted July 24, 2005 Author Report Share Posted July 24, 2005 I was able to retrieve the PCM parameters. How do I find out if they fall in the normal operating range, and can it be reset in diagnostics? The factory service manual is an invaluable resource. You should be able to confirm the MAP reading by using a good vacuum gauge and a barometer. I already asked you to post the reading for parameter PD02; while you're at it, PD01-PD11 and PD36-39 might be useful too. The car was not running. The PCM parameters are as follows. PD01=5.4 PD33=.28 PD78=0 PD02=82 PD34=0 PD78=0 PD03=82 PD35=0 PD79=0 PD04=28 PD36=128 PD80=.000 PD05=31 PD37=128 PD81=.0 PD07=51 PD38=128 PD82=.000 PD08=8 PD39=128 PD83=2 PD09=2.456 PD40=.00 PD84=64 PD10=.0 PD41=0 PD97=1306 PD11=0 PD42=0 PD98=2 Pd12=0 PD70=21 PD99=1106 PD13=0 PD71=111 PD15=12.0 PD72=0 PD16=0000 PD73=0 PD17=0010 PD74=.000 PD30=.0 PD75=1.035 PD31=.0 PD76=4.000 PD32=.00 PD77=28 I thought I would list all the codes. Is there a site that list them and the normal operating range? Thank you in advance. Link to comment Share on other sites More sharing options...
KevinW Posted July 24, 2005 Report Share Posted July 24, 2005 The car was not running. The PCM parameters are as follows. PD01=5.4 PD33=.28 PD78=0 PD02=82 PD34=0 PD78=0 PD03=82 PD35=0 PD79=0 PD04=28 PD36=128 PD80=.000 PD05=31 PD37=128 PD81=.0 PD07=51 PD38=128 PD82=.000 PD08=8 PD39=128 PD83=2 PD09=2.456 PD40=.00 PD84=64 PD10=.0 PD41=0 PD97=1306 PD11=0 PD42=0 PD98=2 Pd12=0 PD70=21 PD99=1106 PD13=0 PD71=111 PD15=12.0 PD72=0 PD16=0000 PD73=0 PD17=0010 PD74=.000 PD30=.0 PD75=1.035 PD31=.0 PD76=4.000 PD32=.00 PD77=28 I thought I would list all the codes. Is there a site that list them and the normal operating range? Thank you in advance. The 'normal' range would depend on the operating conditions. The service manual suggests minimum/maximum acceptable values, but some interpretation is needed. The MAP reading (PD02) prior to start-up indicates the barometric pressure (PD03). I suppose 82 kPa would be acceptable for Denver, but closer to sea level, I'd expect 99-103 kPa. I wonder why PD32 (front O2 sensor voltage) is at 0.00 volts; PD33 (rear O2 voltage) is more reasonable. At key-on, the voltage would start at the reference (0.45 V) then drop gradually as the heating element warms it up. See what PD32 reports while running, and compare it to PD33. PD98=2 means there have been two ignition cycle events since the last trouble code was set, or the battery was disconnected recently. ___________________________________________________ Link to comment Share on other sites More sharing options...
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