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<x-charset iso-8859-1>Jim, I had this problem caused by several things: - bad or disconnected throttle switch (enrichment circuit off ) - wrong version of manifold pressure sensor (way too lean) - bad spraying injectors (way too lean) - timing not advancing (rusted stuck, very gutless when cold and uphills when warm ), Check your timing ! My main cold problem was that the engine was running way too lean when cold. Every engine must run rich when cold , that is why carbed engines require a good working choke in order to suck in more gas, injected engines receive a 'more fuel ' signal from the temp sensors during the cold and accel movement from the throttle switch. Enrichment can come from the pressure sensor if your EFI version has the accel enrichment in the pressure sensor. The pressure sensor is essential for fuel mixture, if it is faulty or the wrong one you may end up with a lean condition or a rich condition. When the engine warms up or heats up , fuel demand goes down and the engine can be leaned out and still work very well but if the same amount of fuel is applied to the same engine when cold, it may not start and if it does , it will run somewhat ugly and weak. The temp sensors regulate the amount of fuel going in, depending on engine head and air temps. All of these causes listed, caused my problems but the main one I found to cause the most grief, were my injectors, they stayed lean when engine cold and also when warm. Ran like crap when cold, very slow car, top speed 25-30 mph. When engine was warm , top speed was 50 mph , at this blazing speed the engine felt like it was pushing and pulling. I found that the injectors were clogged/worn , the junkyard ones I bought did not give the best expected results (I thought it was fixed but was not sure beacause only experience was with big V8's ). I ordered injectors from a rebuilder (PYTHON) and decided to test these using my injection system and the trottle pump, found that volume of fuel per same number of injections was very different between rebuilt injectors as much as 50 percent and a couple cut out at an equivalent of 2800 rpm., I returned these several times before getting others from another rebuilder (BRET) and new from Bosh , these last two vendors injected more and evenly, all the way across. Good injectors changed the way my engine worked so sooo much , good power and top speed of 100 mph and a cold engine now is more peppier than when warm, engine temps are down and fuel economy is better because of less full open throttles. Injectors seem to last 30 years before the inside is worn and scuffed by years of contamination. Old injectors can be cleaned by some injector shops but I was told mine were beyond cleaning and they seized or fuel cutout at higher on/off injection rates. Check your spray pattern from each injector pair (diagonally from each other at different engine positions, ignition disconnected and injectors spraying in a bottle or can) . You should see a conical pattern, no peeing streams or mishapen cone patterns. If you have a throttle pump feature on your throttle switch, you can spray the injectors with a pumping action at the throttle, you will hear a clicking sound. You can also pump vigorously to check if your injectors are cutting out , more vigorously they inject , the more bad injectors quit spraying. Study your particular system , ask us questions. I hope you find your problem. LEON MARTINEZ 1969 SQUAREBACK EFI/AUTO 1967 FASTBACK PROJECT. SAN DIEGO AND TIJUANA . ------------------------------------------------------------------- List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org </x-charset>