| Author | Message | ||
     max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 32 Registered: 02-2003 |
Hi all The truck would stall at highway speeds like it was being turned off and on. #2 it takes a bit of cranking to start. The 60k maintenance was just done. I thought vss and bad injectors. She took it to LR and they said bad fuel pump, replaced, the next day same problem. Back to LR and they say bad vss, replaced. The truck runs good for a week (still has a hard start) and stalls at the train tracks and wont start turns off the ac and radio the truck starts but idles rough. She pulls into pep boys and the say bad alt. still stalls at stoplights and low idle. I did a search and found a lot about the stepper motor. I do not know what this is or if the 97 has one. Help? Where should I start? max | ||
| Brent (Silly_me) On Probation Username: Silly_me Post Number: 82 Registered: 07-2003 |
The stepper motor is the idle air bypass valve. Have you replaced your fuel filter? Fuel Pressure regulator? You would think the dealer would have tested your pump before replacing it...... | ||
| max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 33 Registered: 02-2003 |
Thanks Brent The fuel filter was replaced with the 60k check-up. The regulator has not been changed. The dealer said thy "test" the pump but i'm a sceptic. The Disco belongs to a friend and she takes it to LR for everything, but this time she doesn't feel like they know whats going on so she asked me. | ||
| Sergei Rodionov (Uzbad) Member Username: Uzbad Post Number: 66 Registered: 08-2003 |
Max - stepper mottor is also known under name "idle air controller". I had heck of the time to figure what everyone was talking about too  . Its basically small thingy on the back of plenum cover (i think its there from 94 onwards), that designed to let air into plenum while gas pedal is depressed - hence throttle is completely closed. On my 94 its located on left (if you facing car) rear side of plenum. You need to disconnect plug and then use sure-grip or wrench to slowly get damn thing out. Cleaning it (petrol, carb dissolver.. something like that) might be key to get rid of rough idle. Another key might be dirty T-section on air valves that goes to flame catcher and crankcase breather (to be sure just disconnect those, and also hoose that goes from plenum to that stepper motor - and just wash damn things in petrol or something like that till they really clear). Those should be checked like every 12/24K miles but i am not sure everyone does it, as mine were contaminated by LOTS of crap. So was stepper motor. | ||
| max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 34 Registered: 02-2003 |
Thanks all I will try some cleaning and see if that helps. seeing as i'm a night owl i'm going to bed but if anyone else has more to add please do and i'll look at it tonight. Thanks for the help Max | ||
| Joey (Joey4420) Member Username: Joey4420 Post Number: 234 Registered: 04-2003 |
It may even be a slightly clogged fuel injector....Worth some good injector cleaner to make sure. | ||
| max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 35 Registered: 02-2003 |
Thanks Joey I thought about the injectors and think she needs to pull them and have them tested. Update: the truck only stalls when it has less then 1/2 tank of gas. Max | ||
| Joey (Joey4420) Member Username: Joey4420 Post Number: 241 Registered: 04-2003 |
Has she changed the fuel filter yet....my '97 did the shut down thing at high way speeds, but did not shut off at idle....Changed the fuel filter and havent had a problem in 10k miles. | ||
| john heath (Jheath6) New Member Username: Jheath6 Post Number: 35 Registered: 09-2003 |
make sure the alt belt is on right | ||
| Joey (Joey4420) Senior Member Username: Joey4420 Post Number: 253 Registered: 04-2003 |
Here is a good link for things to check if not running smooth.....should be applicable for the 4.0 as well as the 3.9 other than distributor stuff. http://www.britishpacific.com/disco/FAQ_roughrunning.html | ||
| max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 37 Registered: 02-2003 |
Thanks all The filter has been changed and I looked at the hoses in and out for leaks all is good. I think it is an injector problem. The part that gets me is if she has a full tank of gas it runs fine no stalls but it still has the hard start. When the tank is less then half it stalls at stops (but not all the time). If the fuel regulator is bad would the level of fuel in the tank make a differance? Thanks for all the help Max | ||
| Sergei Rodionov (Uzbad) Member Username: Uzbad Post Number: 72 Registered: 08-2003 |
Fuel tank ventilation thingy? If it stall again - try to go and open/then close tank cap. See if it will runs again smoothly for a while, and then stalls. It can be case when tank cant restore pressure that developed by sucking fuel away. If thats the case - check tank cap - i think on your year it should be "venting cap". Might need change. | ||
| max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 38 Registered: 02-2003 |
venting cap? I know on the 97 if the cap is not seated right it will throw a code for a vacumme leak. Max | ||
| Bazzle (Bazzle) New Member Username: Bazzle Post Number: 17 Registered: 09-2003 |
http://www.britishpacific.com/disco/FAQ_roughrunning.html This site seems to have all the answers to your questions as Joey said Bazzle | ||
| max garcia (Max_n_erica) New Member Username: Max_n_erica Post Number: 39 Registered: 02-2003 |
I did a search before I started this thread and saw that. Did a clean and added a fuel treatment. Not sure if this helped or if it was just that the tank was full again. Should know more on how it is doing later today. Max |
