325i cold start

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shanehaward
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Post Wed Nov 26, 2014 2:38 pm

ive recently bought a facelift 325i and its a real pain to get running when the engines cold.

It will fire eventually but you have to pump the throttle, once its running it idles ok but if you push throttle too quickly it will kind of misfire then stall, as soon as it gets up to temperature its much better but not 100% it will start up straight away though.

ive replaced the blue temp sensor but that made no difference.

shane
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Post Wed Nov 26, 2014 2:54 pm

shanehaward wrote:
ive replaced the blue temp sensor but that made no difference.
You need to test the blue temp sensor (hot and cold) from the ecu to eliminate any issues with the wiring between the ecu and blue temp.

There is an article in the wiki in how to test.
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Gavla
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Post Wed Nov 26, 2014 2:59 pm

I thought if you pump the throttle it will flood the engine...
shanehaward
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Post Wed Nov 26, 2014 3:05 pm

for some reason thats the only way it will start..
shanehaward
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Post Wed Nov 26, 2014 3:11 pm

could it be the fuel filter?
Grrrmachine
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Post Wed Nov 26, 2014 3:14 pm

Could be lots of things:

1) Corroded wiring at the C191 corrector, causing the blue temp sensor readings not to reach the ECU
2) Numerous air leaks in the intake system
3) Sticky/gummed injectors giving a bad spray pattern
4) Stuck open injector or perished hoses causing fuel pressure to drop overnight

That's a quick list to get you started!
shanehaward
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Post Wed Nov 26, 2014 4:46 pm

ive just taken the airbox off to look at the air filter, its not too bad but the afm is really gunked up. whats the best thing to clean t with and could this cause my car to hesitate when i press throttle hard?
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Brianmoooore
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Post Wed Nov 26, 2014 7:00 pm

Measure the 'blue' temp. sensor resistance at the ECU socket, with the engine stone cold and then at full working temperature before you touch anything else.
shanehaward
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Post Thu Dec 04, 2014 7:11 pm

thanks for the replys, i dont have a multimeter but i will borrow my grandads one on the weekend.

i cleaned the afm out and starting problems have now stopped, starts straight away now but it still misfires under heavy load (revs perfectly when depressing throttle gentle) also thick white smoke. Idles fine
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Brianmoooore
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Post Thu Dec 04, 2014 7:29 pm

Brianmoooore wrote:Measure the 'blue' temp. sensor resistance at the ECU socket, with the engine stone cold and then at full working temperature before you touch anything else.
shanehaward
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Post Thu Dec 04, 2014 7:34 pm

ohh.. :o: i thought you meant before i spent anything on it. i will not touch anything else until i measure the resistance on the blue temp sensor this weekend.
sorry and thanks brianmoooore
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Post Sun Dec 07, 2014 12:56 pm

Distributor cap & rotor.
The touring had similar issues until I change them.
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shanehaward
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Post Tue Dec 09, 2014 7:51 pm

just looked at the distributor cap looks pretty new but is held on with just 2 bolts and one was finger tight, i know this wont help but could it cause the engine to splutter when you blip the throttle?
shanehaward
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Post Tue Dec 09, 2014 7:52 pm

idles perfect and throttles fine if you depress gentle
shanehaward
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Post Tue Dec 09, 2014 7:54 pm

ill clean the terminals and get a bolt on the weekend anyway, just seeing if this is likely to be my problem