'88 325 - starts hard - check engine light on

My new to me 144k 325 which has been a joy to drive for 108 trouble free miles needed lot's of cranking to start this morning. I crank in 10 sec tries and then rest. I guess it took about 5 tries. It was 48F
and wet. I don't normally depress the gas pedal when I crank but after a few failed attempts I started a panicked pumping and holding the pedal down etc. Finally started. Ran fine most of the day then the "check engine" light came on. The fluids were all good and the temp normal so I just drove on. The next time I parked it wouldn't start, just cranked. Same deal, after a few tries it starts and the "check engine" light goes off after a few minutes of driving. Any idea on where to start with something like this? I tried turning the key to position one and pumping the gas pedal 5 times but I couldn't start the self diagnostic mode so maybe my model doesn't have it. The inherited tech report from last August said it had the tank and line cleaned out and the fuel pump replaced. A new battery was fitted and then the car would stall at stop signs, starting normally afterwards. No engine codes. Wire wiggling was found to solve the problem but no one was sure what they did right. All the oil change lights are on and some one covered them up with a sticker so we wouldn't have to look at them. That's all I know. Thanks as always.
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Holding the pedal down really doesn't do much on EFI cars. Could be the cold start circuit has a fault (coolant sensor would be my first guess there) but I'm actually leaning towards a different diagnosis.

The check engine light is most likely the O2 sensor. You can get the original part for around $80 or fit one for a 1990 Ford Mustang (5.0 litre) for around $30. Replacement is easy and straight forward.

88 and earlier used an older mnotronic version that didn't include the self diagnostic mode. Some have been fitted with newer ECUs but the stock ECU was a no go.

Check the reference sensor and it's wiring (passenger side near the harmonic balancer) forfaults. If this wire is broken (but still making contact) the car may run but stall out or fail to start due to vibration. Also, check the cap and rotor and the condition of the plugs. If the cap, rotor and plugs are good and you have spark when the engine is refusing to start, that will give us a direction to go.
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I'm not sure about Motronic, but pumping the pedal on some EFI systems pulses the injectors beyond the 'normal' as a richer mixture is needed for quick engine response to demand. Could be this is inhibited during cranking, though. A wide open throttle when cranking can get the engine going if it's flooded - but don't pump obviously. Standard proceeder on some E39s which have been started from cold then near immediately stopped - like moving out of a garage and stopping to close the door, etc.
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On Fri, 12 Oct 2007 18:40:41 +0100, "Dave Plowman (News)"

If you depress the pedal some more after it feels like it's at the bottom of it's throw you can feel a switch clicking. Any idea what that does? Is there a cold start proceedure for this car? Thank you, I'm waiting for the Bentley manual.
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If this is an auto than this is the "kickdown" switch that puts the transmission into the next lower ratio depending on speed and has nothing to do with cold starting.
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On Fri, 12 Oct 2007 12:28:54 -0400, Michael Yeager

This is located just below the header meets the exhaust pipe? I googled for parts and prices but there's a zillion connectors with the 3 wire walker "direct replacement" being common to most sites at $50 for the Ford and $125 for the BMW. You're right, the picture looks the same for both.

http://www.unofficialbmw.com/repair_faqs/sil.html Found this for resetting the oil change light and dash panel batteries. The diagnostic connector is round and located on top towards the radiator?

Thanks, out of curiosity, what's the oil bath thing on the drivers side near the air intake? It seems to be just a reservoir fed from some type of crankcase breather. The fluid in it looks awful. Today the ABS light came on for about 10 minutes and went off again. The check light started flashing but it drove ok. When I had a passenger in the car there was a rumbling and vibration from the rear of the car or driveline which went away when they got out. The cruise control stopped working for a while for no reason I could see. Then it worked fine next time I started the car. Maybe I inadvertently disabled it. Everyday a new adventure.
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wrote:

most likely cause is a faulty O2 sensor, there are several other reasons for the check engine light to come on.
This light indicates that the engine is sending more polution to the outside world. This happens when the mixture is not optimum, but the range of mixtures for good operation of the engine is quite broad. Thus, it can easily be that the light will be on, the engine will be running well, but it is also sending more of the bad products of combustion that is allowed by the regulations.
Jim
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I used the part for the Mustang and just spliced my connector onto it. Match the wire colors and it's all good. The part I used was a 4 wire and the odd wire just got grounded to the frame.

Big round connector with a Pac-Man looking hole in the middle (after you remove the cap) I'm sure it's the same one you're looking at... :)

My bet is your looking at the power steering reservior. There's a filter in it and you can buy a new reservoir and replace it and the fluid at the same time.

Many trhings can cause this. Worry about it if it happens all the time or the light doesn't go back out.

Maybe tire balance or wheel bearing.

The cruise control is a fairly simple system but you can't disable it. Quite possible you just didn't activate it. :)
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