UK Car Repair: vauxhall astra., throttle position sensor, astra mk3

Question
hi, i am having a little trouble with diagosing a problem with my astra. it is a mk 3 1.6i and the engine stalls when coming up to a junction and on trying to restart the car sometimes it fails to restart, never starts within one or 2 seconds and i have to really push my accelerator to make it start. i have also noticed that on restart it lets out alot of black residue from the exhaust and sounds like lots of little pops. all garages that i have been to so far have not a clue about what the problem could be. i recently managed to get in touch with a friend of a friend who suggetsed it may be the idle control valve that is faulty, i have recently replaced the valve and still the engine keeps stalling. i was just wondering if there was anything that you knew it could be.
thanks look forward to hearing from you.
anna hill.  

Answer
Astra Mk3... Around 1996 or so? Five door? Automatic trans? It sounds like one of three things. The Throttle Position Sensor is my first suspect. The Mass Airflow Sensor, Or a Major vacuum leak possibly from a split intake air tube between the mass airflow sensor and the intake. Is the smoke you see a misty gray color and smell slightly of sulfur? That is a sign of over fueling and the popping is the fuel burning in the exhaust system. I feel you could also have a leaking injector or possible an injector that is stuck open. You will need to find a garage with a machine called an Exhaust Gas Analyzer. This machine is able to detect the amount of oxygen and unburned hydrocarbons in your exhaust fumes and tell how much fuel your car is actually burning. Any well operated garage worth its wrenches will have one. It allows the garage to gain input past the cars own diagnostics system. General Motors "A US Company that is barely a breath away from collapse" markets this car in the USA as the METRO. These cars are well known for sensor failures. Find a garage with a sniffer and see if they can figure out where the additional fuel is coming from. Unfortunately, without laying hands on the car it is rather difficult to determine an exact aria to focus on. However; your local mechanic should be able to find the problem provided he looks for it. If it only happens to you take the mechanic with you and try to recreate the symptoms. Sometimes different driving styles can mask the problem. If you run into any snags or have any more information drop me a line.



Anna! I just had an epiphany! I have a 1999 Panoz that was doing the exact same thing and the first thing I did was clean the throttle body! I'm sorry it slipped my mind the first go around. It's a fairly simple procedure and is noted for solving a myriad of drivability issues. Here they are just to help narrow it down. Stalling on deceleration, rolling "loping" idle, rough idle, off idle or tip in hesitation, stalling when shifting into gear.
Try having the throttle body cleaned "must be removed to be done properly". let me know if it helps the situation.