| Author | Message | ||
     Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 110 Registered: 01-2003 |
My 95 D1 has a bad idle, it hesitates opon acceleration from idle. The problem seems more pronounced when the truck has been at operating temputure for a while. My truck ran fine last week and on saturday, tired starting it on sunday and it was hard to start and now has a very rough idle. I checked my cap and rotor, plug and wires. I replaced all of those about 700 miles ago and all seemed fine. I checked my timing, it to was right on. I double checked all wire connections for corrision and if they were on tight. I put in a fresh tank of gas. What drives me crazy is at speed the truck runs just fine, also I had no issues on saturday. Suddenly on sunday the truck craps out. Any thoughts? Fuel filter? Injectors? bad coil? stepper motor? maf? The truck has 105K and starts hard, but stays running, tries to stall, but never quite gets there. Any help would be greatly appreciated. Thanks | ||
| Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1203 Registered: 02-2002 |
Andy: By the time our trucks get to be as old as yours and mine, many things can begin to wear and show the characteristics yours is. Could be so many things. Start with the stepper motor and go from there. I've gotten it down to injectors on my truck so that's my next step in search of a smoother idle. I'm just hoping it isn't camshaft wear... Paul | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 111 Registered: 01-2003 |
I hear you on the camshaft wear. I plan on putting in a new fuel filter tonight and cleaning the stepper motor. I think I might check the coils impedance cold and after I run it for a while. | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 112 Registered: 01-2003 |
I'm bumping because I am going home soon to get some parts and to try to fix my truck, so any ideas? I know I'm impatient | ||
| Chris Browne (Chris_browne) New Member Username: Chris_browne Post Number: 32 Registered: 02-2003 |
you're checking the right things, don't forget the airfilter too. | ||
| Rick Clarke (Tugcap) New Member Username: Tugcap Post Number: 12 Registered: 02-2002 |
Andy Keep us posted. My 95 still idles fine, but would like to hear the rest of the story. Thx Rick | ||
| Rick Clarke (Tugcap) New Member Username: Tugcap Post Number: 13 Registered: 02-2002 |
BTW, when was the last time you did wires, plugs, rotor and D cap? Rick | ||
| James (Jimmyg) Member Username: Jimmyg Post Number: 201 Registered: 10-2002 |
My 95 with 178,000 miles is starting to do the same thing. Starts, then tries to die and then runs fine at speed. I'm thinking something with O2 sensor and injectors. | ||
| Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1205 Registered: 02-2002 |
Jimmy: Don't bother with the oxygen sensors unless the light is on. I just replaced mine after 165K annd no change in performance or fuel economy. At least it was an easy fix. Peace, Paul | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 114 Registered: 01-2003 |
Well messing with it last night, I checked the timing again and put my old wires, cap and rotor back on, and no change. I am pretty sure that the ignition is not my problem, I also checked my coil impedance hot and cold, it to appeared to be fine. Then I pulled out the stepper motor or idle air bypass valve and wow it was a mess. I cleaned it, the hoses going to it and pulled the block it screws into theat attaches to the plenum. After cleaning and putting it back together I started it and the truck still did the same thing. When I put the a/c on the truck will stall at idle, I am starting to really suspect that my stepper motor is bad. Any one know how to test the motor/valve? The service manual said there is a resistance test for it, but I guess thats in the electrical service manual, which I don't have. I am off to search the archives. I let everyone know what I figure out. | ||
| Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1209 Registered: 02-2002 |
60 ohms across each set of windings. | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 115 Registered: 01-2003 |
Thanks, I'll check that asap. I found this link, useful information; http://www.jpurnell.com/RR/repairs/Air%20Bypass%20Valve.htm | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 119 Registered: 01-2003 |
Well I put in the new stepper motor, a Wells AC-102 from autozone $34.99. The truck idles and runs fine cold. Not even hard to start anymore. But now when the truck get hot, or up to operating temputure, it coughs accellerating from a stop. Run the truck for a while, like my work commute, and it started to cough under any acceleration. The longer I run the truck the worse it got. Any ideas, any temputure sensitive parts I should check? I'm pretty sure it's a problem related to the fuel system, as the truck in time and all the ignition parts look fine. I doubt the fuel injectors are clogged as the problem should show itself when cold, but it seems fine cold. Also no vacume leaks and air intake parts look good, also no leaks or clogs in the exhaust system. | ||
| Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1226 Registered: 02-2002 |
Coolant and fuel temp sensors? | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 120 Registered: 01-2003 |
Good ideas, I check those over lunch. | ||
| Jared Schnelle (Jared) Member Username: Jared Post Number: 56 Registered: 09-2002 |
Andy, I have a similiar problem on my truck. I've replaced quite a bit lately, and it's still doing that. I have a new fuel pressure regulator, fuel pump, stepper motor, coil, plugs, wires. I'm going to pull the injectors pretty soon and ship them off to be professionally cleaned, repaired. This probably wont be for a week or more, but when I get them back I'll let you know if it helped any. Paul, do you by chance know a place to purchase both sensors? | ||
| Paul T. Schram (Paulschram) Senior Member Username: Paulschram Post Number: 1227 Registered: 02-2002 |
Lowest cost vendor is almost always Discount Rovers. Most reliable is almost always Rovers North. Next best vendor is usually DAP. There are some others who are less reliable and less economical. | ||
| Andy Thoma (Andythoma) Member Username: Andythoma Post Number: 121 Registered: 01-2003 |
Is there any kind of gm or generic that works as a replacement part for those two sensors? I'm going to try the disconnect the sensors when the trucks doing its 'cough'. I had little time but I checked the plugs and both looked okay. I read in the archives the sensors are cheap, so I think I'll try to replace them. |
