Wont Start

[320guy 0]

So this morning I go out to my car to go to tech, and the battery is flat and it cranks slowly and fires once, when its cranking it was showing about 4000 - 5000rpm but I think it always does that when the battery is flat.

Anyway so I stick it on the charger and come back later, and it cranks really fast (like it has no compression at all) and it seems louder then usual when cranking (like a louder whining noise from the starter) but im not sure if its just me or not.

Anyway, it still wont start, so I pull a plug and it has water droplets on it (probally condensation cause it was cold this morning). Check for spark and there is no spark, except it sparked once, when it did spark it was strong.

Battery was flat again after mucking around with it so put it back on charger. Went out again, tried starting it, its firing alot like almost starting and if I hold full throttle it fires alot quicker and almost runs. But thats about it, battery went flat again so it is back on charger.

Also the rev counter is reading normal again when cranking. So since it is firing its getting spark now. Is my fuel pump dead/on its way out? I havent pulled the line off the FPR yet to check how much fuel is coming out, and I dont have a gauge to measure pressure either.

Its low on oil, the low oil level light is on, on the checkpanel. Check the oil its on the lowest mark, but it still has oil pressure. Would the ECU prevent it from starting on low oil? Im getting some more oil tonight when mum gets home.. Car is a 89 320i.

So, any Ideas?

[320guy 0]

OK The rev counter is absolutely dead when cranking... So faulty VR sensor or ECU?

Edited June 13, 2007 by 320guy

[pureboiracer 0]

tek? u go to weltec by any chance? take your fuel lines off your pump and turn the ignition on for a second see if fuel comes out.

[320guy 0]

Nah wintec...

I took the fuel line off at the fuel rail and theres fuel there when cranking.. Tach is completly dead while cranking.. someone said that their e30 does that normally on some other forums.. Can anyone confirm if their car does the same?

Edited June 13, 2007 by 320guy

[OLLIE 26]

electrical or air intake problem.

run a jump wire from the positive side of the battery to the positive side of your coil and turn the engine over, see if it starts now. this basically just bypasses the ignition and establishes whether the problem lies in the ignition circuit or if it's somewhere else.

Or it could simply be that your battery is not providing enough current to fire a big enough spark on all the cylinders, fully charge up the battery and pull out all your spark plugs to check for fouling and electrode gap, make sure using a feeler gauge that the electrode gap is 0.8mm, if not reset the gap or replace your plugs.

check your distributor, clean up all the connections and make sure all leads have continuity through them.

Pull off the airflow meter and check that it's moving properly and not sticking, in the cold whether they can cease.

this is one of those really annoying things to trouble shoot, but hopefully this gives you a base to start narrowing down the problem.

[320guy 0]

Sweet, I got the battery on the charger tonight and will f**k around with it tommorow morning..

Thanks.

[hotwire 352]

From your initial description - firing while on full thottle -sounds like it is simply flooded. Can do this if cranking to slowly where it is still fueling the engine without burning it.

With good battery power try holding "full throttle" while cranking, holdind down until it clears & runs before easing off.

If no go after 45 - 60 seconds of continuous cranking, remove all plugs & dry them, pull the coil HT lead from the distributor & earth out.

Then with full throttle crank the engine for 10 -15 seconds to clear, refit plugs (& lead) & it should go.

Good luck

[320guy 0]

Tried the trick with the wire from the battery to the coil, no difference. All the plugs are in there tight as a nun. Got one out, checked all the other leads for spark, they all have strong spark. Although the plug seems to have quite a big gap, I dont have any feeler gauges but will pick some up today and re-gap them. Pulled the AFM off, the flap moves freely, cleaned out the filter as it was full of leaves.. Will test the AFM's resistance shortly..

[320guy 0]

Didnt test the AFM, apparntly its tricky on the newer AFM's. Pulled a plug again after cranking for awhile and its dry. They are all sparking. Last night when I pulled the fuel line off and cranked it there was plenty of fuel. Maybe my pump is f**ked and there is not enough pressure?

[j_tomo 0]

you didnt get it wet by anychance did you?

my 325 dies if the engine gets wet yet the dizzy cap has no moisture

it will crank over and fire like its running on 1cyl

also wont start if i leave it out side and theres a frost

ill look into it in the weekend

top up our oil?

jeremy

[320guy 0]

Sounds like your injector harness plug is corroded maybe.

I got my car running anyway. Not sure what was wrong with it, I managed to get it running for 5 seconds with the, fuel pump unplugged, temp senders unplugged, afm removed from throttle body but plugged in, fpr vacuum hose unplugged. And it would start and run for about 5 seconds untill it ran out of gas, then if i plugged the fuel pump back in it wouldnt start, unplug it and it would run for 5 seconds, plugged the afm in, the temp senders, fpr etc. Wouldnt run at all, even with fuel pump unplugged. Got sick of it, left it for a few hours came back out, plugged everything back in, and it started straight away! Being driving it for a few days and its being fine, although a bit hard to start when its warm. I topped it up with oil aswell

[sven007 0]

Im having a VERY similar problem, my 325 I took the battery out and charged it voer night, went and put it in the next day and only the electricals work but it wont start up. I thought maybe it could be the battery is old and needs replacing? Could this be a reason?

Cheers

[320guy 0]

Does it crank? If it does, test to make sure you have spark. Also test that you have fuel at the fuel rail, disconnect the main fuel line from the fuel rail (located just under the FPR) be careful because it may be under pressure, and put the pipe into a clear bottle, get someone to crank the engine, alot of fuel should come out. If you have fuel and spark, either your injectors arnt opening or your FPR is stuffed. There is a connector under the intake manifold for the injectors, and it is prone to corrosion which stops the injectors from opening, find that plug and unplug it and check the pins, make sure they arnt corroded. If they are clean them up with some contact cleaner or WD-40.

One way to test the FPR is to disconnect the vacuum line at the intake and suck on the vacuum line to the FPR, becareful as you might get a mouth-full of fuel. If fuel comes through the diaphram in the fpr is stuffed, if it holds vacuum it should be sweet.

Other than that you could have somthing completely weird like I did and never know what it was