Scotty Posted July 16, 2004 Report Share Posted July 16, 2004 Have you considerer that you may have an exhaust restriction? I saw the post about the ignition module also, have you eliminated that? I think you need to systematically eliminate potential problems one by one... Can you summarize what you have done so far? Mike Link to comment Share on other sites More sharing options...
Marika Posted July 16, 2004 Report Share Posted July 16, 2004 Have you spoke with the mechanics who installed your TPS unit and found out from them if they set it up correctly in the computer? Scotty is right, the correct way to troubleshoot is to do one thing at a time. If you try to tackle even two things at one time, you'll never be able to isolate the problem and fix it. If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans. Link to comment Share on other sites More sharing options...
92 deville-loveit Posted July 16, 2004 Report Share Posted July 16, 2004 MOst assuredly the 92-93 Deville 4.9L has a limp mode when the compuer shuts down four of the cylinders. This doesn't have much effect at high way speeds on level ground or down hill but ... when stopped and 4 people are in the car ... it becomes a real dog. I had this problem occasionally when my TPS was psssibly "dirty" inside after I cleaned the trottle bore with out removing the ISC motor or TPS. THe TPS did "heal" itself asd as for the ISC motor ... it and its two screws are in a sandwich baggie under my front seat 5000 miles and a month later. I am meaning to reinstall it but the car is in constant use and I haate burning my fingers. for the gurus out there or anyone that deals with lots of caddies ... what should the tps angle be at clsoed trottle. Mine varies from 1.2 to -8.8 degrees and the voltage is an almost perfect .502 volts. Yesderday when I ran diagnostics it was 0.2 degrees. IF YOUR CAR GOES INTO THE LIMP HOME MODE ... and you are sure that nothing serious is wrong ... you can clear the codes while the car is running down hte highway ... press Off and Warmer till the segments all liht up in the a/c panel and the fuel gauge (FDC fuel data center). Then watch the codes at the FDC. First will be the current codes that will be followed by the stored "history" codes. That will be folowed by a 7.0 when done press Off and fan HI to clear all codes. press LO fan and you will get a number/code E9.0 (this tells you that you are in the PCM data mode.) Then press HI once and you get the TPS angle in degrees (P.0.1) press again and you get map reading (P.0.2) press agian and you get calculated current atmospheric pressure (P.0.3) (when I was in the Rocky Mountains two weeks ago, I used this to estimate my altitude.) press again and you get coolant temp (P.0.4) and again the under hood temp of air going through air cleaner (P.0.5) press again and you get the amount of advance in degrees (P.0.6) press again and you get battery voltage (P.0.7) and again you get engine rpm/10 (P.08) . press again and you get the vehicle speed. (P.0.9) (I have only memorized and used P.0.1 - 9). Keep pressing and you get 10 more items the last being the PCM prom number (P.2.5). GM replaced my prom by many others afterwards because of ... you guessed it TPS problems. Alas mine is the original #393 (that tidbit of info about proms came from a snap-on book, that I got with my code and data MT-2500 scanner. If you press HI one more time you get the tps reading again (P>0.1) and the process has gone a full circle. Pressing LO after being in the data display mode allows you to go backwards to a previous reading. I have copied 4 pages of my service manual that explain this data and the codes and how to run the computer diagnostics and I laminated them back to back into two plastic sheets that I carry in my passenger seat pocket. When my car is acting up I grab the sheets and check out the meaning of the codes as I clear them. I live with e22 and e70 ... but I expect they will go away when the ISC motor is reinstalled as it also contains the closed throttle switch. THat switch position is displayed in the air condition control panel when in diagnostics. It is very easy to check ... put your foot in and out of the gas and you will see the icon (lighted segment that says OFF) change. The engine does not have to be running for that test. IF anyone wants a set of laminated pages like mine ... I will do it for $7 email me at ibmpro@ez2.net. Everything above and lots more is on those 4 pages. 92 and 93 Sevilles shared the same Helms factory service manual as both cars are identical mechanically. As for this 93 Caddy's problems .... if a customer gave me $50 for parts to fix it and told me to do my best for the least ... I would go buy an ignition module. I had the almost exact same problem on my 86 Olds Cutlass supreme and Fianlly I was able to finally prove it was the module but not until it had let me down making me wait for it to cool off and start working again. This happened many times. (I hate to buy parts needlessly. In my case I was lucky. It was a typical 100+ day here in the desert and a cup of icewater revived the module instantly sevearl times after it died in a 30 minute time period.) I still have the old bad module in the glove box as an emergency spare. When the module is working it works perfect ... when it gets too hot it dies but as soon as it cools off it works again. On my 92 Deville when my module got hot it did not die completely, but only lost spark advance. That I could see in the engine diagnostics (P.0.6). But I also saw that the IAT was even higher then the engine coolant temp and I knew that was not good or right in a moving vehicle. I reduced that temp by changine gears and manually turning on the radiator and a/c fans (via engine diagnostics (E.5.8) and the module worked perfect. I don't think it was designed to run continuously at over 240 degrees F. There fore I have not rushed out to buy its replacement. Would a new one work better? I doubt it. Now that I am home in the hot flat dry desert (100+ and wild fires a mile away twice this week) and I have emptied the overloaded car (I had a lathe and an air compressor in the trunk all the way form Connecticut) ... the car is running flawlessly. 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98Concours Posted July 17, 2004 Report Share Posted July 17, 2004 Interesting! I thought only the NS had limp home mode. Jeff Jeff 98 Concours 90 Seville 04 Corvette Link to comment Share on other sites More sharing options...
Ranger Posted July 17, 2004 Report Share Posted July 17, 2004 I do not believe the 4.9 has a "limp home mode". Link to comment Share on other sites More sharing options...
KHE Posted July 18, 2004 Report Share Posted July 18, 2004 MOst assuredly the 92-93 Deville 4.9L has a limp mode when the compuer shuts down four of the cylinders. The 4.9 engine does NOT have a limp home feature. Only the Northstar engine has that feature. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
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