help guys, strange no starting problem - found it finnaly!

[michael24m]

very strange stuff has been going on for one month now. when cold starting, it goes but about 2-3 cranks and then dead, it doesn't rev past 300rpm. firstly i replaced the sparkplugs, then it went ok. after that the problem started again, same condition. checked the cold start injector, spraying ok, electrical wise ok. then checked the airmeter, sensors ok, flap ok. then same problem, very heavy cold starting remained. somedays it starts ok, then when warms runs beautifully. 2 days ago, i found a crack in the big hose from the airmeter to the trothle house. finnaly i thought i solved the problem. yesterday went beautifully, went to warm, revved smootth perfect. tonight when i went to start the car: the same f*** problem! i actually couldn't start it at all. just 2-3 strokes and goes dead. same exact symthoms as before. these weeks i checked everything: fuel is comming, pump is ok, sparks are perfect, cold start injector ok, sensors ok. no vacum leaks. i have no clue anymore... in this condition if i crank it for 2-3 hours continually eventually it would start. but one day tried crancking for half a day just to the limit of the battery and it would'nt start. the day after that, same thing but started heavily after 5 mins of cranking.

when cranking like this, it starts smelling of gasoline, but there is no leak anywhere, the smels comes out the exhaust. i reapeat: i have sparks ok!
help pls!!

[Widge]

I wasn't aware there is a cold start injector.
You failed to specify what engine you have in the car mate, although I can't help it may help others to diagnose.

[michael24m]

the car is a 320i m20 6 cyl, L-Jetronic injection.

[JOSEMI]

it happened ot me after I didn't used the car for 4 weeks, and the cold came in...
Changed the dizzy cap and the rotor arm, wacked a little bit the engine to wake it up (totally nackered the old rotor arm it was the b*****d) and it goes cream now

Edited: sorry I forgot to say that my engine is also a 320 jetronic. You just need to tidy a few parts and give it a wack, they tend to get 'sleepy' when out of use

its worth the try, hope this helps

Jose

[michael24m]

thanks, Jose!
i took a look at the distributor cap and the contacts were half eaten away, the rotor arm still has 1 mm of metal on so that's ok, got to replace the cap, i'm pretty sure that's the fault.
i will find out for sure in the morning when the new cap arrives.

[michael24m]

fited a new distributor cap, still no go!
exactly the same sympthoms as before, i could crank it half a day and nothing, at first 2-3 strokes then nothing.
checked everything, i have no ideea what to do to it anymore.

[JOSEMI]

Right, I see you have an issue there mate, now which one it is is something that is beyond me.
As a process of elimintation, you have changed the dizzy cap and the rotor arm, and that is a step in the right directinon.
I have not had problems with the starter in my E30 yet, so I am not entirely sure if that is the problem in your car. I have had problems with the starter in an old escort (typical), and the problem then sounded pretty much like yours. The car would start sometimes, and other times it just wouldn't start. The starter becomes temperamental, specially in cold mornings, and makes a raugh noise when you turn the ignition on. Is your car making this noise when you try to start it ??

Some one in the zone with experience will confirm this, and will say if it is indeed the starter that is causing problems on your car. Brianmoooore wil surely have an answer to this.

Jose

[michael24m]

thanks jose, well it doesn't make any noise except the normal crank 2-3 strokes and dead, and cranking maybe another 2-3 strokes and cranking and cracnking without starting.

[JOSEMI]

Ok.
There are a number of things I think you could check on your car for peace of mind

- it could be fuel starvation, haven't had problems with this before so Im no expert, the fuel filter or the ignition cables (you said that you checked the spark plugs) could fail and leave the car with no spark or fuel.
- a leak in the air intake boot which but you have already fixed
- I am more inclined to think that there is something which needs cleaning in the ignition process, as by the looks of it once you start the car goes fine ??

Give Brianmooooore a shout mate, see what he says. Brian is one of the many zone experts and has enough skills to tackle almost any problem. I wouldn't want to give you advice beyond this if its not going to help. But don't give it up chap, it can be fixed and it could be something as simple as a bad conexion !

HTH

Jose

[michael24m]

thanks mate,
i checked the spark leads and they are ok, no vacuum leak that's double checked, fuel pump system ok, it's like fuel is rushing in the engine but there is like nothing to ignite it. and this is the strangest thing because i have sparks at the sparkplugs. now i haven't been able to start my car for 2 days now.

[Widge]

Simplest engine theory - 3 things you must have, Fuel, Spark, and Compression. I'm not saying it's not somthing else, cos I know nothing about Jetronic, but if you are sure you have fuel and spark it's the next step.

[michael24m]

yes it does sound like a no compression problem. but how and why? the weeks before when i was able to start it after an hour of crancking it went very rough and chocked but when warmed up eventualy it was running smooth. can i have no compression just when starting? and like i said sometimes after hours of cranking it eventually starts. but sometimes it doesn't start even if i crank it a whole day. i think eventually i might ruin the starter motor cracnking like this.

[Brianmoooore]

No compression problems tend to be permanent, rather than intermittent.
You've got 6 cylinders, and the engine will run happily on three, so this is unlikely, although a quick compession test wouldn't hurt of course.
The fuel smell after cranking points to lack of sparks. Are the plugs wet with fuel if you take one out after cranking and unsuccessfull starting?
Connect a small ( 5W ) 12V lamp to the ignition coil + terminal and earth. Check it lights with ignition switch and stays lit while cranking.
Connect the lamp to the coil - terminal and earth and check that it flashes during cranking.

[bigkev]

sounds like it is overfueling try and block the fuel pipe to the delivery rail with something like a vise grip(carefull not to pinch the pipe) and give it a couple of cranks it might take a while to clear the cylinders but if it starts and then dies after a second or two thats your problem

[michael24m]

just finished checking the ignition coil, it's ok, sparks ok, took the sparks out and cleaned them, crancked and aired the engine out, put them back in, started it started for 5 seconds and then dead. i kept on cranking and then 2-3 strokes, until it was so overfueled that it doesn't ignite at all.
it sounds like what you said, bigkev, overfueling, but if this is the problem, how do i solve it?
thanks

[Widge]

Sounds like a buggered fuel pressure regulator.

[michael24m]

that's the big lump on the left hand side of the engine compartment and to the bottom, right? resembles an oil filter and the fuel feed comes from it to the cold start injector and to the injector rail. so deff overfueling, the fuel press regulator is the culprit?
could it be the ECU also?

[Widge]

Dunnoo I don't know the layout of Jetronic systems. Someone else will be able to tell you.

[michael24m]

OH MY GOD i found a picture of the fuel pressure regulator, i always thought that was the one, but today when i removed the fuel line from it and see if it receives fuel, i found out that that feed line was the return. while cranking the fuel came out of the fuel pressure regulator being pumped trough the other side of the injector rail. can this be true? the fuel presure regulator fittet to the return side of the fuel rail?

[Widge]

Unlikley I would have thought, but I shall eat my hat if wrong.

[Martinaston]

Fuel pressure regulator goes into the return pipe.
Have you checked the crank sensor and wire ?

[MONSPORT42]

Been having problems with relays on cold mornings myself. They seem to work OK when the car warms up. Seems to remember having a similar problem with my old 323i jetronic and that was the fuel pump relay. Just putting 2+2 together and making 44. But it's an easy check. Prior to Brian's reply I would have put my money on the low tension lead from the coil breaking down/bad connection. Good luck

[michael24m]

i just got upstairs from checking out the feed, return pipe, i reversed them and after that i just read the manual, and seen that the presure regulator is indeed on the return and after that i read the post on the forum confirming that. i should have informed myself in reverse order

well i jumped the relay pins and made the fuel pump run continuosly, anyway pumps ok, but with the relay on, while cranking seems to overfuel, so a bad relay posibility drops right?

[michael24m]

came back from the university and started to work on the car again. it's been over a month now since i wasnt able to start the car again.

i renewed all the distributor parts, rotor, distrib cap, fitten a new ingnition coil and tried with that. still the same problem. i also checked the ignition control unit, that is separate from the ECU on the L-jetronic system. electrical wise, the ignition is ok, spark is perfect.
ive been to a dealership, and they advised me that certainly the bugger is the ECU, or the air mass meter. but i checked the air mass meter before and it was ok.

the fuel pressure regulator is ok, fuel pressure is correct, but the engine is still being overfueled. when i clean the the sparks and put them back in it gives 2-3 strokes at the most and then goes dead.

could it really be the ECU?
i have no ideea anymore

[clemQ]

alrite dudes.
i had a 5 series (2L) as well with those probs. as it got the same engine it may be the same things. basically it might be a combination of things. if you look at the throttle body on the inlet there are water pipes which in my case was leaking (a tiny bit but it all adds up) on to the wiring contolling the injectors so they was just spraying in a higgledy piggledy fashion. it also turned out the throttle pot was inactive as well as the idle control valve. so all together the car was running like shite (sometimes not at all)
so i cut the wet wires out, got new throttle pot and idle control valve from german swedish (expensive shit) and wham bam thank you mam problem sorted. of course i took it to a bmw specialish who ran a diagnostic to find out all these problems before so i suggest you do that. ( Ԛ£60)
i hope that helps

[michael24m]

thanks ClemQ! i checked all these things out and there are ok here, mine's a diffrent problem though. it is so strange... it seems to be overfueling, but the pressure is correct. after a few mins of cranking, the fuel gets exhausted unburned, and it got fuel into the air meter now, and checked the oil level and in got into the oil bay, seems i have to change the oil again, after sorting this out. hopefully soon:((

again might it be from the ECU? the ecu controls the injector injecting timing. if that's screwed up i think it doesn't syncronise with the spark timing or something.... i think my car needs a priest really.
here for the price of a new ecu, i might buy a whole motronic engine alltoghether, and just my luck the scrappers here sold out all of bmw parts. a year ago when i didn't have any problems with it, there was a hall full with bmw engines from the 80's going very cheap....

[Globulator]

This does seem like a very tricky problem: compression + fuel + spark = no running. Bizarre.

The fuel smell MAY be a build up as it doesn't get burnt like the design expects. Interesting you got it running for 5 secs.

FYI:
The fuel system pressurises between the pump and the regulator. The regulator is just a sprung pressure valve, all other pipes are at tank pressure (zero) so the regulator HAS to be on the return end.

What I would do.... is block the fuel line or disconnect the fuel pump fuse - i.e. stop the fuel. Then get a can of Easy-start - it's magic stuff and I've run old 6 cylinder Jags off of them. Ideally it will just start and run off the easystart mist (get a mate on the starter or the can) so the engine can clear itself of fuel and you know the spark is OK. If not - you may need to spin the engine sans plugs to clear it first.

Then replace the regulator (watch for fuel spray - also for perished fuel pipes inc the feed pipe twiddling up from the filter under the inlet manifold).

Then try with regular (design) setup and see if you have any luck.
Also remember if the mixture is rich - you may need to open the throttle a bit to get it to start - I'd have a first go at half throttle but don't blow it up when it starts!

[michael24m]

Thanks Globulator! i should have mentioned this before, but i already did all the things said above, except the easy start spray.

firstly i heated the sparks, dried them out, cranked the engined without the plugs in and aired it out. after that, i removed the fuel pump relay. and crancked with that a bit. the most i got out of it is 2-3 strokes and then dead. and further cranking would do nothing. i represurised the fuel system, removed the relay and tried again, still nothing. i should mention that the car runned perfectly before, and it wasn't paused more that 3 days without driving it.

the problem was intermitent, sometimes went and started perfectly sometimes it couldnt start like now, and finnaly it turned into a permanent no start problem.

i should say that until now, i checked every sensor, checked the complete ignition system, the fuel lines, no leak whatsoever, all ok, i have become addicted to the gasoline smell

my father after asisting me with diagnosting the engine this time, was amazed and thanked god for the carburettor system of his peugeot 405

[Jami]

I have a 320i 1989, with similar problems. It starts first time, but will not restart if i turn it off.

I have tried clamping the fuel line and removing the fuel pump fuse, which seems to help, but i am not quick enough to replace the fuse or remove the clamp. Plus as an engineer i dont belive this is a real solution, something tells me this will never impress the ladies!!!!!

Let me know if you solve the problem, and i will od the same.

[michael24m]

Jami, from what you described your problem might be easier to solve.

You said that when you clamp the lines or remove the fuse it works(mine doesn't start even then:() the problem might be the incorect pressure in the fuel system. it might be a faulty pressure regulator, the one on the end of the injector rail.
if you could reroute the fuel feed line with a T to a manometer, a pressure reading device. if the pressure is between 2.5 - 3.0 bar then the pressure is corect, and the problem is similar to mine.
if the pressure exceeds 3.5-4-5 bars, or is below 2-2.5 bars then the pressure regulator is the bugger. the correct fuel pressure specification for this engine is 2.5-3 bars. hope this helps!

[michael24m]

found the fault!!! it wast really the stupidest thing, mixed with strange coincidences. the injectors was the fault!

when the problems started i didn't bother to check the injectors, because i already checked them a month before, and they were al spraying nice.

after looking for all the air leaks, i started to go on the ingition components problems route, finished with that, gone on the fuel pressure route. finnaly i said what the heck let me check the injectors took out the rail and conected it out and cranked: one injector was out on holidays, and the others were presenting a spitting contest.

now, in one month's time, how ALL 6 injectors, at once, went from well to very poor performance, i have no ideea i didn't run on empty tank or something. at least i finnaly found the fault.
that proves that one should never asume anything, nothing is obvious, check and recheck everything

is there any way i can clean these out? or should i just start replacing them?

thanks!

[Brianmoooore]

Sure it's not low fuel pressure making them spray funny?.

[michael24m]

hmmmmmm you got me thinking here, they seemed to be squirting like they didn't have any power. i have a friend who specialises in diagnosting injectors, and would test them at 3.0bar in 2 days.

another thing, what is the voltage aplied to the injectors by the ecu?
i measured them while cranking and the voltage was 0.5-1.5 volts. is that correct?

[JJ26]

Just a tip from experience, check the earth strap to the engine and from the battery. Also have you checked the plug to the ecu, small chance of corrosion maybe? Ive had a jetronic ecu fail on my opel manta before... The injection system was from a astra and i fitted it to my manta and all was well. Few weeks later with more time i decided to relocate the ecu from its temporary position and in the process provided an earth to its casing, because it had one on the astra!.... it never worked again, it just totally flooded the engine repeatedly. Coincidence maybe?

[JJ26]

Just remembered also, i dont know if the bmw jetronic loom is the same but mine had 2 earth leads together bolted to the cam carrier, these are very important as they supply earth for firing the relay and injectors. I know because it came loose while driving once and the car was spluttering then going for a while and then stopping! Then spluttering trying to start because the lead was bouncing from the engine movement! Worth a check.