ok this is rather interesting. I did get the water pump fixed thanks for the help on that !!!! this was the first day we took it out, we drove it all day. and on the way home i set the cruise control at 70 or so. when i did the truck continued to accelerate on it's own we got up to about
100 mph and i hit the brakes to shut the cruise off, it continued to gain speed.i used the brakes again but the engine kept cranking. i managed to get it stopped but the engine wasn't . i had to shut it off. when the tow truck guy got there he unhooked the cruise control and we started it back up and the engine went wide open so we instantly shut it down. the throttle cable is not stuck which makes it more confusing. the tow truck dude said something about a tps or throttle position sensor..... does anyone know anything about these? glad i was driving and not someone else that could have been ugly.
=========================== Sorry but, with the info you just gave your little story is impossible.The throttle had to open to go that fast. It doesnt matter if the TPS said it wide open, it has to BE wide open for that to happen. You better re-check you throttle from the pedal to the plate. Or stop telling stories :)
ok? I am not telling stories. while the tow truck guy was there. we look at the cable and had my mother push the accelerator. it did then open. when she let off it went back. now as for seeing anything happening inside the engine as for fuel injection and that stuff i don't know. i am not a mechanic by any means . I just called the local Chevy dealer and they said it sounded odd as well. i'll get it figured out and let you guys know. it might be something of interest to some of you....
"~Perkins Racing~" wrote in message news: snipped-for-privacy@storefull-3197.bay.webtv.net...
It is possible... the throttle position sensor tells the computer how much the throttle plates are open and the computer will inject the appropriate amount of fuel. If the tps has a short it may, at one position, tell it to idle then immediately tell it that it is wide open. But for the engine to rev up the throttle plates will have to be open enough to burn the fuel or it will flood out. You don't have error lights??? Has the speedo been working properly? Has it been shifting properly? I am going to assume you have a throttle body (not familiar with 97 trucks), I would make sure the throttle cable moves smoothly and the throttle plates move smoothly. Get a good volt/ohm (from walmart or similar) meter and a service manual. The test the resistance of the TPS, it should change smoothly as you push the throttle open. If it jump then this is you problem. The tps would account for the over rev once the towie was there, after he unhooked the cruise control. Did he unplug it from the throttle body (i.e. yank the cable off) if he didn't then maybe your cruise control was not really off and when you started it up again it all of a sudden realized the truck was not going 70 and tried to accelerate. If it was me I would check the resistance of the tps (service manual will tell you the proper resistances) and unhook the cruise cable from the throttle body. If it still does it then you know the throttle body or the computer is the problem.
The more I think it sounds like the cruise control was stuck on. Maybe the vacuum solenoid is stuck open sending vacuum to the diaphragm. This would cause the truck to run away from you and once you restarted the truck it would build vacuum and open the throttle plates. Maybe somebody here can tell you the resistances of the tps but the first thing I would do is unhook the cruise diaphragm cable from the throttle body and go from there. If this is what it is then you need to trace the vacuum circuit to find the supply solenoid. If I remember correctly I think the control solenoid is actually part of the diaphragm assembly...
================================ There is no sensor on the truck that can make it go 100mph by itself. It had to be the cruise or stuck throttle. My guess at this point is the cruise did it and the tow truck driver diconnected the throttle cable. Lets us know.
It was indeed the cruise control cable, it was stuck .a buddy of mine at our local chevy dealer got a kick out of the fact i pulled it with a tow strap 25 miles and he unhooked it then i drove it back home. I just didn't realize how much actual movement there was on the throttle on the engine i could move it by hand a few inches but when he unhooked it . it went a few more. My fault i am just learnng this good stuff. i am ready to quit learning for a while and just want to drive the damn thing. lol Have a Great One and Thanks
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