Hi, My Jetta3 cli guage is showing that the car is overheating. The electronic console unit reports correct temperatue 94 degrees. The car is using in excess of 14L/100km. This is attributed to the car thinking it is over heating and therefore supplying more fuel. The four pin temp/fuel which was causing the car not to start properly (but displaying correct temperatue). I've changed the four pin temperature switch (with the same yellow colour code), the car now starts properly but is using excess fuel and reports overheating. Any idea?
Is the car an automatic, if so quickly check the transmission fluid levels and make sure they are where they should be. Is the car actually overheating or is it that it is just reporting overheating. I confess I never heard of a system that would respond to overheating by burning yet more fuel.....seems all wrong. If the car is overheating it could be because the car is actually burning more fuel. The fuel air mix is always enriched when the engine is cold at time of starting. Very quickly as the engine and the catalytic converter warm up the fuel is leaned out to normal running mix. Two further sensors to check are the air intake temperature sensor on the air intake pipe and the lambda sensor on the exhaust manifold. Either of these if faulty could allow the car to keep the fuel mix rich as the system still considers the car to be in cold start mode.
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The computer will very likely be generating engine fault codes if you have quite excessive consumption and there is no point in guessing what the problem is as there can be numerous causes. You have not mentioned if you have a check engine light showing but if you don't just yet you soon will if the problem persists.
1. Go to a reputable mechanic and have the car scanned for fault codes because it will be very likely throwing some codes if you are having a high engine fuel consumption issue (as opposed to a loss of fuel from the fuel system due to an external fuel leak).
2. On thing you can do yourself is remove the old dusty air filter element in the air intake box ( which no doubt has not been changed since ????) and put in a new OEM air filter unit. A dirty clogged unit will cause your engine to run poorly.
Hello, There are several causes for excessive fuel consumption . Dirty or clogged air filter, leaking gas hose or fuel lines, under inflated tires, wrong sized tires, excessive weight in the trunk, a heavy foot on the gas pedal are only a few.
HI do you now the color of the smoke if engine emits white smoke its not burning the fuel it could be water mixing with fuel = head gasket even tho you dot have water in the oil if engine emits black smoke - that's excessive fuel to air ration check air filter & air inlet to see if clogged if engine emits blue smoke - excessive oil consumption cloud be valve seals
Hi,black smoke from tail pipe is unburned fuel ( excessive fuel consumption ) so your not firing on all cylinders!!! ( that's where the surging is coming from ) if i recall the 88 model has a carburetor.( not tbi,or injected) but either way its going to be in the spark! start with the easiest/cheapest and work your way up... will be like a #1.bad spark plug wire, or #2.bad plug, #3.bad distributor cap,#4.bad distributor rotor,#5 bad electronic distributor module. will be one or more of those items that's bad.......good luck..yz-maniac
May be oxygen sensor which also regulates fuel. That plus temp sensor is main inputs to fuel control. As 02 sensor fails computer can send wrong amount fo fuel and this will eventually burn up your cataylic convertor which will cause more problems. scanners are hard to come by on bosch systems but you need to get some info on voltages coming from 02 sensors and look for cross counts which is an indication of reaction times for the sensor. It should show movement from high to low voltage as the computer adjusts fuel. If the signal is staying in one range the computer will keep adding fuel thinking it is running lean. Hope this helps a little. If so please reply as this helps me continue to answer questions here and good luck
this could be an air intake problem, check the air filter but what ive seen before is the flexible intake pipe collopse only when the engine was under pressure as you describe.Try removing this pipe & driving again but not for long as dust would enter the engine .it might confirm or elimiate this.