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Everything posted by teamzr1

  1. Hi Logan Thanks for the time and effort in getting an image for me. ! Hope this is not too hard to get to be able to replace PSP switch
  2. Hi and thanks for the reply Is this for a 4.9 L 1993 Deville and is that next to the exhaust pipe, image kinda small so was not sure ? Thanks
  3. If having a fuel pressure regulator. If it has a vacuum hose, while at idle is take the hose off and see if any fuel comes out and regulator is leaking would need to be replaced Using a fuel pressure gauge connected to the test port of fuel rail see what the fuel pressure is with key on, engine off, should read at least 35 PSI Turn key off and see via that gauge if pressure holds or quickly bleeds down showing leak somewhere including fuel injector(s) Otherwise, need a full OBD-II scanner and see if the problem happens when the engine is in open or closed loop. If closed then look for how the fuel trims look, is MAP and MAF reporting correctly, etc
  4. HI All ON the subject of the Power Steering Pressure Switch Having moved to an area where the summer is very hot my 1993 Deville 60 special 4.9L engine On random basis on startup the idle would go nuts and sometimes engine dies No DTCs trip and OBD-I shows all looks good as to fuel trims, MAP, timing etc. So I assumed it was the ISC and replaced it, though this issue then seemed better over some cold starts the problem still exists but happened less. I assumed then it was a thermal issue as the weather went from 100 deg days to low 80s. Used 2 different ECMs, Memcals and calibrations and both have the same issue Car has over 210,000 miles on it, but more about car's age that some sensors are original and get weaker. So I started researching this, and it hit me a weak PSP can cause idle issues It is even labeled as part replacement as : 1993 Cadillac DeVille Idle Speed Control Power Steering Pressure Switch - 10218778 AC Delco - $24.18 I understand testing the PSP with an Ohm meter with steering wheel flat straight will show open and when wheels are locked hard either direction then circuit should then be closed Question is having PSP not fully going faulty but having degraded cause the idle issue ? I did a simple test where on cold start kept the wheels dead straight and idle was perfect around 650 RPMs for good 5 minutes. The began turning steering wheel back & forth (half to full wheel to wheel) and sure enough idle RPMS change. Put the wheels straight, idle fine and again back/forth on steering wheel and RPMS go up and down So where physically exactly is it for 1993 as from engine bay I could not find it ? Is this on the rack and only can be seen/replaced jacking front end up and getting under there and if so, can PSP be replaced without having to take other things out ? I assume being down there then taking PSP off that will lose most of the power steering fluid and when PSP is installed have to add fluid and then bleed the system ?
  5. Hi Bruce and others I notice your in Plano, Tx I just moved from Oregon to Greenville, Tx which is just east of you I used to work for GM at the Tech center in Warren, Mi back in mid 1980s to early 1990s Frankly you need to find a better dealer or shop as their diagnostics game plan is lacking So just doing some thinking 1. PCM uses a 5 volt ref to several engin sensors such as CAM, Crank, TPS, APP, MAF, AIR, etc. So if the fuse for 5 volt (of PCM) or the PCM itself was faulty there would be a lot more problems and DTCs tripped so to me that leaves it is not a PCM issue 2. You did not mention if the engine goes into limp mode, if it does I would go right to diag APP (gas pedal and TPS) as 2 of your DTCs are drive by wire issues. Depending on model year APP consists of 2 or 3 pots, the TAC (DBW controller) is doing multi checks to assure APP is not faulty and would cause a run away vehicle and cause a crash. Simply with a good OBD-II scanner (as I show below ) even with just key on, engine off APP and TPS can be seen if APP and TPS agree or not. 3. Also, can use the scanner to see if 5 volt ref is functional 4. Should be checking for TSBs for that vehicle as many times the problems are weak crimps of wiring pins or the wiring loom has no slack such as to APP and causes stress to wiring pins connections As example : SUBJECT:Service Update for Inventory and Customer Vehicles Main Engine Harness Wire Chafe Expires with Base Warranty MODELS:2016 Cadillac ATS-V This service update includes vehicles in dealer inventory and customer vehicles that return to the dealership for any reason. This bulletin will expire at the end of the involved vehicle's New Vehicle Limited Warranty period. PURPOSE This bulletin provides a service procedure to inspect and, if necessary, reposition the main engine-wiring harness on certain2016 model year Cadillac ATS-V vehicles. In some of these vehicles, the orientation of the main-engine wiring harness could cause the wires to contact and chafe against the right-front valve cover bolt and washer. If the engine-wiring harness insulation is compromised, the vehicle’s tachometer, powertrain, and automatic-braking systems could be effected. While this condition could—if uncorrected—cause a loss of propulsion or the activation of the automatic braking system, GM has no reports indicating that either event has occurred on a vehicle in the field. This service procedure should be completed as soon as possible on involved vehicles currently in dealer inventory and customer vehicles that return to the dealer for any type of service during the New Vehicle Limited Warranty coverage period. So check for other TSBs such as VEHICLES INVOLVED 16 ATS-V TSBS Check for how the DTCs are defined will help zoom into the areas to look at first such as : Symptoms of a P2135 code can range from stalling when you come to a stop, total lack of power, no acceleration, sudden loss of power at cruise speeds or stuck throttle at current rpm. Additionally, the check engine light will illuminate and the code will be set. Potential Causes of P2135 DTC It's been my experience that the wiring connector or "pig tail" on the throttle body gives problems in the form of a poor connection.The female terminals on the pigtail corrode or pull out of the connector. Possible bare wire on pigtail shorting to ground. The top cover on the throttle body distorted preventing the gears from turning properly. The electronic throttle body is faulty. The accelerator pedal sensor or its wiring failed. The engine management computer has failed. The TPS sensors were not correlating for a few seconds and the computer needs to be cycled through its relearn phase to restore active response to the throttle body, or the computer needs reprogramming at the dealer. Diagnostic / Repair Steps A few points about the electronically controlled throttle. This system is incredibly sensitive and vulnerable to damage, more than any other system. Handle it and its components with extreme care. One drop or rough handling and it's history. Apart from the accelerator pedal sensor, the remainder of the components is in the throttle body. On inspection, you will notice a flat plastic cover on the top of the throttle body. This houses the gears to actuate the throttle plate. The motor has a small metal gear protruding up through the housing under the cover. It drives a large "plastic" gear attached to the throttle plate. The pin that centers and supports the gear fits into the throttle body housing and the top pin fits into the "thin" plastic cover. If the cover is distorted in any way, the gear will be compromised requiring total replacement of the throttle body. Pull the electrical connector out of the throttle body. Inspect it closely for missing or bent female terminals. Look for corrosion. Clean any corrosion using a small pocket screwdriver. Place a small amount of electrical grease on the terminals and reconnect it. If the terminal connector has bent or missing pins you can pick up a new "pigtail" at most auto parts stores or from the dealer. Inspect the top cover on the throttle body for cracks or warping. If any are present, call the dealer and ask if they sell just the top cover. If not, replace the throttle body. With a voltmeter, probe the accelerator pedal sensor. It will have 5 volts for reference and next to it a varying signal. Turn the key on and slowly depress the pedal. The voltage should climb from .5 to 5.0 smoothly. Replace it if the voltage spikes or it has no voltage at the signal wire. Look online for wire terminal identification on the throttle body of your vehicle. Probe the throttle body connector for power to the throttle motor. Have a helper turn the key on and slightly depress the pedal. If no power is present, the computer is at fault. If there is power the throttle body is malfunctioning. -------------------------------------- If problem is resolved, problems still might happen but it could be now that APP and TPS are NOT rezoned to PCM Some GM makes to rezone TPS as to angle of TB butterfly is with key on, engine off, disconnect the wiring connector of TPS PCM will trip a TPS DTC and set TPS angle at zero angle, go key off, plug TPS connector back in, turn key back on and PCM will rezone TPS angle to zero, Clear any DTCs JR _ Team ZR-1 Corvette Racing - Custom GM PCM and TCM Tuning
  6. Hi All This is related to my 1993 Deville 60 Special with 4.9L engine which has about 200,000 miles on it I will be replacing the sparkplugs & wires, fuel filter & fuel pressure regulator that may have never been replaced before or at least the 20 years I have owned the car I ordered sparkplugs, wires, new fuel filter, & a fuel pressure regulator and should be here by the end of this week. Looking for tips for doing the swaps 1. Where is the fuel filter exactly located ? Any special tools needed to do the swap, and if so what size ? 2. I can barely see the fuel pressure regulator and cannot tell all that will be need to do the swap until I take off the air filter assembly Any tips to do this smoothly, what size tools are needed, what else will have to be taken off to get to the regulator and be able to get to the one mounting bolt and fitting for fuel line attached to it ? Can this be swapped without removing anything else ? Should the vacuum hose to it be replaced or not if it looks OK ? Would it be best to first spray a cleaner to the mounting bolt and fitting for fuel line to break them loose first ? 3. Any workaround or easier way to replace the 8 spark plugs and wires, as engine mounted sideways cannot even see 4 of them and fronts do not look easy either? Thanks for any guidance/experience you have on this JR
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