More damp weather issues

A few weeks ago I started having some starting, and running conditions just on warm up. Now, after a good rain or in a damp spell the car won't start; it spins over great but its like the spark is not happening.

Once it starts it will run for a few seconds and cut out (wants to die) and when that happens the econo gauge swings all the way over to the left and then when it cuts back in the gauge swings back to normal.

The car bucks and carries on till it warms completely up and then things are pretty much back to normal, although starting can still be a bear.

Seems to me Ove used to say that when the econo gauge makes that swing it meant something (like the fuel was okay but the motor had no ignition), I forget what... I'll try a new main relay and see if that helps, I have everything I would need in stock so parts are easy, its just getting the right one!

For some reason I might be feeling a connection with the gas pedal, maybe AFM related definitely likes to start with no gas pedal now that this damp issue has showed itself, and that is not how its been along.

Cheers and thanks for listening, Rick

The econo gauge story makes me think it is the fuel supply, if it stops supplying fuel and there's engine rotation, it will give you infinitely large fuel economy (in mpg), thus moving to the left.

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Michiel 318iS
The econo gauge story makes me think it is the fuel supply, if it stops supplying fuel and there's engine rotation, it will give you infinitely large fuel economy (in mpg), thus moving to the left.

Interesting, when it starts cutting out its like turning a switch off though, maybe fuel relay?

I know that econo meter means something!

Thanks Michiel

I dunno.

The econo gauge swings full left like that whenever you're coasting and take your foot off the throttle. The throttle position switch registers that the throttle has fully closed and that signals the computer to stop cycling the fuel injectors and ignition. The engine is still turning, but receiving no fuel or spark, so the econo meter shows infinitely good economy, until the rpm drops to idle level at which point the idle controller should take over to keep the engine running.

I agree wth Michel, it sounds like it's cutting out the ignition/fuel supply. Not a fuel pressure issue though, like in the pump stops running, because it should take a moment before the pressure bled down enough to starve the engine. But it does sound more like something electrical cutting out causing the injectors and ignition to stop.

Try swapping the main relay.

I experienced a similar problem and also thought that the main relay was defective. Turned out that I was partially correct. It was actually the green (I think) wire at the main relay socket that had corroded and started to give intermitant contact. The green (at least I think that it was green) wire is the signal wire to the fuel pump relay.

Salut, Bob P.

Wow, is this thread ever timely. I am having a similar problem as Rick. For two years, ever since I replaced the timing belt/water pump/etc., my car has started hard in the cold or wet. I've replaced the AFM (based on a 1215 code shown), coolant temperature sensor, fuel pressure regulator, and checked all the wiring, to no avail. I've just lived with it, because it always started eventually, especially if I floored the throttle.

Until this week. Tuesday morning I started the car as usual, drove it for 10 minutes, and parked it. It sat for about an hour in a cold rain, and hasn't started since. It cranks and cranks, but not even a hint of a cylinder firing.

I haven't checked for spark or fuel yet, but it sure sounds to me like an electrical problem, based on how suddenly it came on two years ago, and how suddenly it got worse this week. I sure hope it's something as simple as a wire connection.

Where would I find the main relay and this green wire that connects to it?

__________
Dave
'91 325iX

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Dave_G
Where would I find the main relay and this green wire that connects to it?

Never mind, I found it. No corrosion there, and looks good, but I also discovered that the fuel pump itself isn't making any sound. I guess the next step is to test the main relay (is there a test?) and the fuel pump itself.

Sorry Rick, I didn't mean to hijack your thread. What code do you get when you do the 5-stomps-on-the-gas pedal thing?

__________
Dave
'91 325iX



Edited 1 time(s). Last edit at 10/29/2009 06:39PM by Dave_G.

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Dave_G

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Dave_G
Where would I find the main relay and this green wire that connects to it?

Never mind, I found it. No corrosion there, and looks good, but I also discovered that the fuel pump itself isn't making any sound. I guess the next step is to test the main relay (is there a test?) and the fuel pump itself.

Sorry Rick, I didn't mean to hijack your thread. What code do you get when you do the 5-stomps-on-the-gas pedal thing?

Thanks guys.

No problem Dave, its all in the family hopefully we'll both get fixed before really cold weather sets in- I have not tried the 5 stomper yet, will do. Judging by what everybody has been saying I feel a little closer

The econo gauge reading is calculated on injector duty cycle and speed. No throttle input needed. (And no correction for fuel pressure, I think)

If I'm right, our Motronics open the injectors (split in 2 banks) once every two crankshaft revolutions during normal running. Below 600 rpm all injectors are opened every crankshaft revolution. You should check your camshaft sensor/connector, along with the fuel supply. The fault codes could help finding the first part to look at.

The econo gauge operates differently in NA from the Euro models.
I remember Ove pointing that out.

Could the intermittent connection be the crank sensor giving the computer an indication that the crank is not turning at all?

Bob in Everett

Interesting... Wonder what the difference is then.

Okay, can someone give me the fault codes (I lost the folder) and the complete procedure for a 1988 325is please?

Thanks, Rick

Like this?

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Michiel 318iS
Like this?

Thank you Michiel, for a 3/88 car I'm thinking is a 1.3 motronic, yes?

Is there a fault code series for the older cars; eta and early 2.5 (1987 usa) models? or did they not have this option?

Best Regards, Rick

Another Motronic link

Looks like yours should be a 1.3 (88 onwards).

The eta engine might have it as well, though very limited.

1988 was supposedly the first year of Motronic 1.3. Earlier cars used Motronic 1.1, which had a much simpler output with only four codes.

Further reading:

http://www.unofficialbmw.com/repair_faqs/motronic.html
http://en.wikipedia.org/wiki/Motronic

__________
Dave
'91 325iX

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Dave_G
1988 was supposedly the first year of Motronic 1.3. Earlier cars used Motronic 1.1, which had a much simpler output with only four codes.

Further reading:

http://www.unofficialbmw.com/repair_faqs/motronic.html
http://en.wikipedia.org/wiki/Motronic

Wow

Okay, today I finally got back to the car and did the fault codes, it comes up 1441 so I guess the next damp/rainy day I start pulling relays and see what happens Thanks for all the help, and I'll keep you posted.

Cheers, Rick

Forget everything you've read or heard...check the distributor cap for carbon tracks;you have all the symptoms.

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Archeo-peteriX
Forget everything you've read or heard...check the distributor cap for carbon tracks;you have all the symptoms.

I'll check this out Peter, I have a proper cap and wires set-up for the 2.5, which will replace the eta set-up I have on it now. Somehow though, it doesn't feel like it did a while back when the cap and wires were the problem, BUT, its electrical, so all will be checked out!

Thanks Buddy and all my other brothers here This place is a gift... Rick

It's been said before and it'll be said many times again: this place ROCKS!

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Michiel 318iS
It's been said before and it'll be said many times again: this place ROCKS!

More importantly, it ROLLS!

Oh little Beemie! How do I love thee Beemie!

Kelly

ROCK and ROLL and all that's related to it!

Okay, the other day I couldn't get a bark out of Eubie so I cleaned the main relay (hosed it down with 5-56) and stuck in a good relay; car fired right off and ran perfect for days.

Needed the car this morning and no go, not even a hint of a bark, so I tested the spark, had plenty and then I did a 5-56 job on the fuel relay plug and stuck in a known good relay, next to its main relay brother and it fired up instantly.

So, its looks like rain tonight and we'll see what tomorrow brings I'm really getting pretty tried of this crap!

Bobs main relay wiring issues might be what I'm dealing with; as soon as I start routing around in there the car fires up- electrical, brother, it can sure run you around!

On the hunt for truth and justice (and damp weather issues), Rick

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rkj
Okay, the other day I couldn't get a bark out of Eubie so I cleaned the main relay (hosed it down with 5-56) and stuck in a good relay; car fired right off and ran perfect for days.

Needed the car this morning and no go, not even a hint of a bark, so I tested the spark, had plenty and then I did a 5-56 job on the fuel relay plug and stuck in a known good relay, next to its main relay brother and it fired up instantly.

So, its looks like rain tonight and we'll see what tomorrow brings I'm really getting pretty tried of this crap!

Bobs main relay wiring issues might be what I'm dealing with; as soon as I start routing around in there the car fires up- electrical, brother, it can sure run you around!

On the hunt for truth and justice (and damp weather issues), Rick

Well, it rained all night, and it did start in the morning B)- we'll see as time goes on...

Stay tuned, Rick

Rick, any chance you can assess the condition of the plug sockets the relays themselves plug into? I wonder if you are having corrosion issues at that point? Salt air by the sea?

alan

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alanrw
Rick, any chance you can assess the condition of the plug sockets the relays themselves plug into? I wonder if you are having corrosion issues at that point? Salt air by the sea?

alan

That's a great idea Alan, is there a way to get the wires/and end connector out of the block assy.

I've been wanting to check this area of the wiring for some time now- this coming week I'll get in there and see what I can find.

Thanks, Rick

Hmm, not that I can think of. I know other cars have wiring looms that will run to a firewall/bulkhead connector. Relatively simple to take out the old harness and replace with a new one. I think on our cars, the wiring runs directly to the fuse box or to various components. But it sure sounds like your issue is connectivity as according to your symptoms, it tends to go south when the weather gets wet.

You could always get a wiring diagram and ohm trace the wire runs.

alan

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alanrw
Hmm, not that I can think of. I know other cars have wiring looms that will run to a firewall/bulkhead connector. Relatively simple to take out the old harness and replace with a new one. I think on our cars, the wiring runs directly to the fuse box or to various components. But it sure sounds like your issue is connectivity as according to your symptoms, it tends to go south when the weather gets wet.

You could always get a wiring diagram and ohm trace the wire runs.

alan

I guess I could check from the block (where it plugs in to the relays) to four inches down the wire... Living here, on the east end is a damp salty place!

I'll keep at it :?