QuestionQUESTION: 2000 cirrus 2.4LT. 165.000 km car runs great but about 6 months age when driving steady at about 70 to I'm hr. the car hesitates had a tune up done transmission oil replaced even had the motor mounts replaced by a mech. that told me the old ones needed to be replaced thats why it hesitates $375 later he was wrong so we replaced fuel filter and the Idle air Control relay but it still hesitates,and if you come to a sudden stop it fells like it wants to stall,it has stalled a few times but it starts up wright away we did a diagnostic test and it showed no problems every thing was working fine
ANSWER: Hi Felix,
I would take a look at the function of the exhaust gas recirculation valve which is located in a small pipe that connects a line from the exhaust manifold to the intake manifold, near the throttle body. That valve could function well enough to not set a fault code, yet it could cause a stall when slowing down to stop. It is bolted into the pipe. It has a vacuum line attached to an electrically operated solenoid nearby.
But the item you want to check is the valve stem, located between the valves round top and the body of the valve bolted into the pipe. The stem is hidden a bit by a flange that is between those two parts of the valve but look inside the flange for a rod that has a circumferential slot. That is the stem. You can put a screwdriver tip in the slot and move the stem back and forth. An internal spring will help to close the valve. You want the valve stem to return to that closed position positively, to a dead stop. If it isn't doing so or seems sticky in its action then spray some penetrating oil like WD-40 on the stem where it enters the valve body, then work the stem back and forth until it move well and closes positively. That may be the answer to your problem as if the valve sticks ajar it will lean out the mixture and cause a stall like you describe. It will also cause a stall/hesitation if you step on the gas when cruising at highway speeds.
Roland
---------- FOLLOW-UP ----------
QUESTION: Should I replace this part, thanx for the quick response
ANSWER: No, I wouldn't replace this part unless it seems to have failed mechanically. My experience is that periodically you may find it advisable to lubricate the stem as I described. At some point the inside of the valve may be clogged up which even that can be removed with a wire or wire brush. So try the 'action' of the valve stem and see what you find.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi,did what you asked to do with egr valve,it seemed to work for about 15 min. of driving then it started up again,but you can still fill the hesitation,and a small lack off power going up a small incline,while working on the egr valve I sprayed carb cleaner down the carb,while holding down the throttle I can will the motor has a slight miss, I replaced the gas filter,new plugs wires air filter and so on
AnswerHi Felix,
All I can suggest is to recheck the movement of the valve stem and verify that the spring will close it to the fully closed position on its own. If it does that, then the egr should not cause hesitation.
It may be that you will need to wait a bit more for a code to be recognized. Otherwise it is a frustrating exercise to try replacing parts hoping that you will find the problem by chance. Almost everything else is monitored so a code should show up. You might check that the throttle valve's plate is clean on both side and also the throat and idle air by-pass channel.
Thanks for the report.
Roland
