m20b25 starting problem, PISTON RING ?

[polsta]

need a bit of novice like help if possible on starting issues for a m20b25 pre face

its not been driven for around 18 months, its had a refurbed inlet and rocker and injectors and all new gaskets etc, we got it going the other day it started and was ticking over, pressured up the coolant system and everything ok, bit lumpy idle as expected, didnt drive it, let it heat up thermostat did its job, wasnt much fuel in the car , it then cut out once or twice but re started ok

we left it there as we had to go

since- ive put a couple of jerry cans of fuel in, it wont seem to start now, mate was supposed to do it today but let me down not answering the fone (hungover i expect) it turns over just no fuel maybe getting in ? (i have no idea) but i had it on jump leads earlier for 20 mins it wouldnt start , it turns over wanting too, just that final spark to bring it to life isnt there, ive cleaned the plugs up, ive checked connections and pipes etc, nothing i can see

so tomorrow i need to try do something myself , incase he cant do it after work,ive waited ages as it is, i really need to get it moving and running

what things can i try myself ? any ideas ?

[HJG-E30]

Was the fuel from the jerry cans fresh fuel or has it been in those cans for a fair while?

Were the plugs wet with fuel when you pulled them out? Have you checked for a spark?

[jimbom30cab]

Follow the "I can't start my car wiki" on here it's very good

[polsta]

the jerry can fuel is fresh, took the plugs out earlier and seemed ok, bit black but not filthy, gave them a clean up,- the thread was a biut moist/oily but not the end ?

im hoping my mate finishes the job off tomorrow as it was all his work, i dont wnt to interfere with it all so to speak but im there all day so if there are easy things i can try myself im willing to do so, this however is literally my 1st ever involvement with the m20 engine, all sounded and seemed ok earlier bar the final ignite or fuel, it turnes over sounding healthy but just didnt want to fire up, like something simple was stopping it

cheers jim il have a read

[polsta]

i was having a google earlier- 1st thing il check for spark, that sounds easy enough, then the fuel pump, i presume is ok as it worked the other day fine, the cps- im not sure what type i have, i dont really want to start meddling with things like that incase i balls it up, and interfere with my mates job, as he knows where hes at with it all

just annoying me a call would be nice to say tomorrow after work blah blah, i cant wait days coz i want to get it running so can get everything working then mot it this week

but i presume as it fired up and was working , the cps and fuel pump etc should be ok ? and a bit different to a non styarting car that hasnt started in a long time ?

its maybe feesable the pump as sucked some crap up or something like that ?

[polsta]

I'm here now checking - I've got fuel , and I've got spark ?

[HJG-E30]

May now be flooded from previous attempts. Pull the plugs out, disconnect ignition and remove fuel pump fuse (Fuse 11). Crank for ten seconds or so. Make sure plugs are dry before putting them back in. Reconnect ignition and put fuse back in.

Try again and if it still won't start I would suspect low fuel pressure or incorrect timing (assuming in both cases the spark is adequate). Also make sure all sensors are connected

[polsta]

Thanks hugo, Right dine that , put fuse back and tried again - its different , I now get a click click clicky machine gun like sound that wasn't there before ? Waited a few mins tried again , now its not turning over ? Battery also getting low if that's what's causing that ?

[HJG-E30]

Clicky sound is low battery. Voltage needs to be at least 12V

[Speedtouch]

Try spraying some carb or brake cleaner down the TB.

[polsta]

Ok il go get my truck and try jumping , at no its bit even cranking, but there was a dedicate change of the way it tried and the sound between pre and post fuse 11 and plugs like Hugo said above

[polsta]

Progress !!! I've had it started, got it jumped on my range rover

It seems if I try start it with fuse 11 in it won't have it, if I take fuse out after a few seconds cranking it fires up , then tr again with the fuse in it won't ?

[jmc330i]

It seems if I try start it with fuse 11 in it won't have it, if I take fuse out after a few seconds cranking it fires up , then tr again with the fuse in it won't ?

It will fire up and run without fuse 11 in place?

[polsta]

Yes !!! It will stop after a few seconds but it starts after a bit of cranking without the fuse - you can feel/hear it progressively getting closer as it cranks wanting to start then it starts , ticks over fur a couple if seconds then stops, then try with the fuse in , and it seems that tiny bit of will/progressive better by the crank goes away , try it for a bit then try again without the fuse and it gets better again ?

[HJG-E30]

If there's fuel in the lines it will run for a few seconds with the fuel pump fuse removed (fuse 11) - i.e. it will run for how ever long it takes to burn the fuel still in the lines.

It is impossible for the car to continue running with fuse 11 removed.

it sounds like there is an over-fuelling issue

[jimbom30cab]

i thought that, F11 being the fuel pump and directly in line with the supply (like you would expect for a fuse) unless the fuse box is by-passed

Would bridging the FP relay do this ?

[polsta]

Right I've got it running !!! It's ticking over on about 1200 souunds a tad fast busy constant not lumpy , I ajusted the throttle cable it seems to like it like that

Update 3 or 4 mins ticking over now its sounding ok I think

[polsta]

As said that's exact what it was like over fuelling with the fuse in, then remove it then after cranking and it burning the excess it would get closer to then start

Anyway after a bit if to and throw with the fuse in and out I've now got it running with the fuse in 5 mins if Rickover now no cutting out , its on around 1100-1150 revs sounds quite constant , just letting it pressure up the cooling system watching the temp at around the white line before half at the mo , think I should chance it for a spin round the block ?
Or what should I do ? Jumps are still connected to the range river at mo

[HJG-E30]

Glad you got it started. Did you take it for a spin?

[polsta]

Not yet , I left it off for a while to cool down (temp didnt get above half way) now I've just started it up again its ticking over ok around 1150, mates getting round here in an hour il let him
Have a look and listen then wel take it round the block , didnt wanna try on my own incase it breaks down if he's here we can tie it back , it seems ok and happy ticking over now , think it needs a blast round the block to blow out the cub webs and get things moving , if its all ok il take it to his garage tomorrow they can give it a tune and check over then mot it !!! Fingers crossed

[HJG-E30]

On the M20 the temp gauge can sit in two positions when fully warmed up depending on the thermostat used. Some will sit in the middle and some just above quarter if I remember rightly.

[polsta]

Yeah I think it always used to sit just below half way , it got to there and didn't go above , its just reached that point again ...

Just been fiddling with the lights and fogs they are all working ok, just fiddling with the wipers now trying to get them to park in the right place , pass side seems to sit a touch high , tried fiddling with the arm position and the motor bit , I can get it to sit lower but then it wipes down low over the screen seal

[polsta]

right its starting and ticking over now, however theres still something not quite right mates been round for a couple of hours and theres a bit of a missfire it seems and somethings just not quite right,he was looking at the plugs and checking the leads and stuff, looking at the pipes and inlet and maf etc needs more investigating tomrrow night so have to wait until then and not start it, as it happens they have a 325i auto e30 at work at the moment his boss picked up cheap, so theres a few things hes gonna look at on that tomorrow and he wants to start and hear this from 100% cold

but he says defo wants some new plugs, maybe 1 of the leads is a bit iffy , i think hes going to bring the whole dizzy and leads etc home from the one at work maybe and give it a try

its breathing a little heavy maybe he said and just doesnt seem right somewhere, but hes gonna have a good look at that one at work tomorrow as its running fine and check a few things and be back round tomorrow after work


i wasnt sure if it maybe just needs a little drive and get everything moving and blasted through a bit and everything loosten up as its not been driven in so long its bound to not run and sound 100% ? but he said best not yet

any ideas ???

its all waiting on this now not much else i can do , soon as its running right it can go for the mot

[Speedtouch]

Engines left sitting around for 18 months or so can often be a little lumpy at first. It probably would benefit from a reasonably long drive throughout the rev range to clear out the cobwebs.

Did you allow the engine to idle for at least 10 minutes to enable the base idle settings to be learnt?

Use a multimeter to check the resistance of the HT leads; they should all read around 6-7 kilohms, and certainly no more than 10 kilohms.

[polsta]

thanks for the reply, yeah its been left on idle for more than 10 mins a couple of times today, gone through a couple of heat cycles, to be honest- when i left it ticking over earlier on for a good while, it sounded fine to me, then again im not a mechanic and been driving a diesel range rover for a year, left it for 1.5 hr maybe m,y mate came round we started it - it starts on the key ok without jump now, a vast improvement on not starting at all

and it ticks over and idles, its not even lumpy at times, idles ok, he says theres a missfire , the throttle cable ajuster/idle speed effects it obviously, but then whenever ive ajusted it on an e30 before, it needs a little drive sometimes to settle , then you make slight half turn ajustments from there to get the idle perfect

but anyay - would you say a drive, even just round the block a few times, would maybe sort it? its not veen driven at all yet, as in my post im inclined (then again i am itching to drive it and want it to be sweeet and not £££) ,to give it a little drive , and just see if it blows out the cobwebs, he said earlier"maybe it might" ,. but didnt seem keen to yet, he said just hold fire tilll tomorrow dont start it all day let me come round start from very cold , and wants to check a few things on the one at work

hes not multimetere checked the ht leads, but i can get this thread up on phone tomorrow when hes there if any relevent info to check, he did wrap one of the lead caps in insulation tape, and was tinkering checking various things with the leads and plugs there, hes also bringing a compression tester tomorrow

but would the 10 mins isle thing have anything to do with a missfire ? could a drive generally sort a missfire ? more so if its not been driven in a long time ?

[Speedtouch]

Yes, the ECU will need to relearn its settings, and will only do so when driven under load conditions throughout the rev range.

Taking it for a brief drive won't do any harm.

[polsta]

ok il let him know, to be like i said it sounded ok and definatly not bad or jumpy, and if it were me i would of just took it for a drive and let it go through the rev range and gear changes and get it all moving and a blast through, then see how it was, but he wasnt really keen as it has the missfire, but- would a missfire, be due to the ecu not learnings its settings due to not driven for ages ? and would/could the ecue recognise and fix the missfire itself ? and fuelng etc ?

i admit i am tempted to just open it up in the morning and start it, see if it starts and sounds ok, take it round the block if so

but then he said he wants to hear it 100% from cold and not to and let him check them things 1st, which really i spose i should

[Speedtouch]

Well, it's your car and your mate, so up to you to decide!

You can really only properly decide if it's misfiring after you've taken it for a spin to let the ECU relearn its settings - there may well be nothing wrong with it...

[polsta]

well its not just the missfire, he aid some sort of breathing issue aswell, how about the breathing and stuff ? does the ecu settings effect that and need a run out on that front ? he was removing things and testingf and putting back and all sort of things

[Speedtouch]

I would say it is pointless testing things until you've taken it for a run to at least establish a basic idea of how the vehicle runs.

As you say, if it has been sitting about for 18 months then it will need a run to bed itself in again.

Start with the basics: Is the air filter clean? Are the spark plugs clean and properly gapped, etc.

If it is misfiring, check for inlet manifold gasket leaks using WD40 or similar sprayed around the gasket; if it briefly raises the idle speed, then you have a leak.

Then progress to more in-depth stuff like a compression test, and check the blue temperature sensor resistance, distributor cap & rotor arm, etc.

[polsta]

ok, il speak to him in morn see what he thinks about the drive if you say that

he checked the inlet gasket earlier with wd40 i think, thats a brand new gasket too, plugs are clean , dont think he checked the gap, he said could do with new plugs, he had them in and out a few times checking things, ive got brand new ones comming tomrrow hopefully aswell, ordered yesterday so fingers crossed

as you say you then progress- he said compressioin test tomorrow, and the cap and arm, and was going to bring the ones from that other car with the leads too to jus try

i just dont want to be/seem impatient and just wanting to drive the thing !!! also being hopefull a drive will sort it, but if you say that , it was niggling at me just take it round the block its not had a drive in so long, and gone through a few heay cuycles now and all that messing about with it to get it started today, its surely not just going to be 100% and need a blast out, and theres certainly not any bas noised or knocks or backfires or anything, and was happily idling earlier not cutting out

[HJG-E30]

You definitely need to put the engine under load. i.e. get it warmed up and accelerate flat out in first gear!

Definitely check the air box.... a friend's Evo had a mice nest in there after leaving it for 9 months.

[polsta]

well rain has stopped play today although looks like its drying up maybe ,there will be no drivng it in wet/greasy roads, particularly where its done 0 miles in the las 18 months, hopefully it will be dry later

the airt box/maf etc has all been out and cleaned up, so its not anything there

[polsta]

spoke to my mate today, he seems to think a piston ring may have gone ? he said done a bit of research and thats what its pointing to, although cant be certain, he said its breathing a bit heavy and when you take the oil cap off the engine its sucking in a bit ?

mate from garage by mine had a look, he said possibly, but has it been driven yet ? said no, he said you need to take it for a drive get it up to temp and then have a gentle blast m could have a sticky valve(s) or something and it all just needs a good run out 1st and foremost

im thinking if it was a piston ring, then it would of had to be like that all the time it was on the road and it was 100% fine and drove super never skipped a beat

mate said get it down to the garage save keep messing about at your lock up, and he got all the tools and bits there and can have a good check over it all properly and compression and emissions test it etc, they are mot`ing it anyway so thats where it was heading

so i think im gonna take it for a little drive tomorrow and put a few gentle miles on it, and see how it is , then get it up there in the afternoon, and it will come back with an mot- just a question of how long and how much £


praying it just needs a run out and its nothing major

[Speedtouch]

More likely a sticking piston ring, or valve. Try some Redex down the bores and left overnight to free the rings up a bit.