5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
Hi Guys, I have (as described below) a very Angry 1994 530 V8 Automatic tourer, it moves rather well when it starts. idle is rough, around 450-480rpm, with a working MAF connected it runs sometimes and cuts off sometimes at whatever speed. the last time that happened, i was overtaking at 170kph (yeah i know its not exactly legal to dricve that fast here in Nigeria) engine just lost power suddenly, i pulled to the slow lane, took my foot off the gas, and it stumbled a bit and fired up again. when i start (cold or hot) it cranks and starts the first time most times. if it does not start the first time, it takes continuous cranking with flat out accelerator to start! cabled accelerator, i did a diagnosis which came out with MAF faulty, i changed the MAF and the same thing. i checked the plugs and it is very black (running rich) yes that will happen if the MAF does not work or is not connected, but it runs well without the MAF (no cut-offs in motion) i concluded i have an air leak, which is not allowing the fuel pressure regulator return fuel. BUT what is the cause of the intermittent cut-off? ECU failure? i recently did a 400km trip and burned 40ltrs of fuel (20ltrs/100km) THATS A LOT FOR HIGHWAY TRAVEL!! if thats the normal fuel consumption, so be it.. but why are the plugs black then? DESPITE THE BRILLIANT ENGINE RESPONSE AT ALL TIMES? Thanks In Advance
injectors not leaking... already checked. thanks. today, i disconnected the air intake temp sensor, drove the car around a bit (not good performance) plugged it back with my MAF and it drove like a dream, 5 minutes later after switching off to get a bite, the whole madness started again!!! the strange thing is.... i disconnected the Camshaft position sensor and the car does not miss it at all (ie like it was not doing anything) should the car start at all without it?
"If the hot him breaks or if there is no output from the air flow
sensor, the ECM automatically SWitches to a "limp-horne"
mode and turns on the Check Engine light."
when i disconnect my MAF i do not get a 'bong' neither does my car turn on the MIL light ( i doubt if i have one as i have never seen it) and my car can still kick ass!! JUst takes a lot of gas!!! i get the same fuel consumption either in town or on the open highway!! something MUST be wrong. i can afford the fuel, its just not running properly. the ONLY authorised BMW workshop in Abuja, (BMW NIGERIA) wants me to pay the cost of the car to "diagnose" and asked me to leave the car for about a month because "intermittent problems on cars this old take more time" i felt like shoving my foot in his mouth!!
Changes the MAF (again) and lousy fuel consumption becomes dramatically better like double my former MPG!!! ONLY issue unsolved is erratic idle. thanks Guys
Check all the vacuum lines and intake boot all the rubber hoses and tighten all the clamps. what about the cam pos. sensor that didn't sount right it might be on its way out... run some Seafoam engine cleaner through it. what till you have like 1/8 or a tank and put it in. drive it till almost empty the fill with pre. fuel and drive till empty again
__________________ 1991 Ford Taurs SHO 5 Speed White on Tan
1996 Chevy Lumina LTZ Rep 3.4L
1992 318i Coupe parts car
1992 325i Ls1 swap with a T56 6 speed 12.2 quarter mile
1976 Mercedes Benz 300D with a Ford 5.0L Fuel Injected soon to be Modded I am Captain Obvious
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