When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
General Car Related Discussion.To discuss anything that is related to cars and automotive technology that doesnt naturally fit into another forum catagory.
Hi all. From the day i bought it the cars had a misfire around the point the turbo kicks in.
Basic spec when i bought it was green 803's, t34.63, 3 bar map, swedish inlet, L1 ecu with msd chip and msd wasted spark.
Ive since changed the original engine loom for an aftermarket loom, l1 ecu for a l6 with chip to suit greys, new used 3 bar map, new fuel regulator, new ik27 plugs (standard gap) and set of greys.
Fired it up and took it for a drive today and the misfire seems worse but still around the same place. If i floor it the turbo doesn't even spool up at won't rev up past that point but if i slowly accelerate it still misfires but it will rev through the rough spor and spool up. Ive checked the tps with multimeter and thats fine starting at 4.8v and dropping to 0.5v at full throttle. Ive reset the co2 screw (5 turns clockwise and 2 anti). Im going to drop the spark gaps to 0.6 but im not sure this will solve my problem? I think the iscv has packed up too as it idles up and down until i unplug it
Iv had this very same problem and it was the way the HT leads were rooted and the coil pack was all so playing up . If you have a mate with the same setup try swooping parts one by one
Did you fit only one new ignition amp when you done ws conversion?
Wasted spark was already fitted when i bought the car, all ive done is fit it to the l6 ecu and new loom.
Just pulled spark plugs out and they where all very sooty. Set gaps to 0.6 and its still the same. It black smokes when it misfires so im thinking its over fuelling.
Im thinking
A. Its a weak spark issue?
Or
B. Wrong engine map for my setup causing over fuelling?
Iv had this very same problem and it was the way the HT leads were rooted and the coil pack was all so playing up . If you have a mate with the same setup try swooping parts one by one
That would be great bud but no i don't know anyone but if anyone with a cosworth and wasted spark spark wants to help me theres a beer init?
Quick update.
Layed all the ht leads out across top of the engine so they weren't touching, calibrated the tps but no difference.
Tried setting the base idle but it didn't seem to work.
I then tried leaning the mix by turning the co2 anticlockwise and the more i turned it the better it idled and i was then able to set the base idle.
Drove it up road and back and it seems better as long as i slowly accelerate, if i floor it as soon as it tries to boost its like the engine switches off.
Im taking it to a tuner soon but i don't want to kill it enroute.
Im still thinking its the chip?
I read on your post you have gone from a L1 to a L6 . Can you give a bit more info . Wot did you do about the chip when you swoped over the ecu,s . Wot set up is your car running /turbo/ inter cooler/injectors/HT leads
And be onist it's never good to mess with the mixtcher screw unles you no wot your doing
. Some more stuff to check is the crank pull clean no oil on it is it standerd is the gap right . Is the faze censer set right is there play in the dizzy shaft . Is the timing on the car 100%
It's can be hard to find the problem but if you start at the beginning and check every thing all the way it's surprising how quick you can sort these problems . All so wair do you live witch might be a help to telling you witch tuner to go to
I bought the l6 and greys 2nd hand as a package that came off another car so i kind of knew id have to have it mapped to suit my setup.
Im yet to check the timing but the gaps on the sensors look good.
Im running wasted spark so i had to install the driver into the ecu and wire the ws loom into the new loom.
I know messing with the co2 screw is ill advised without a afr meter but it is running extremely rich and turning it anticlockwise did make it run better.
I bought the l6 and greys 2nd hand as a package that came off another car so i kind of knew id have to have it mapped to suit my setup.
Im yet to check the timing but the gaps on the sensors look good.
Im running wasted spark so i had to install the driver into the ecu and wire the ws loom into the new loom.
I know messing with the co2 screw is ill advised without a afr meter but it is running extremely rich and turning it anticlockwise did make it run better.
Yes, 403s require a modification to the injector nozzle, the end cap has to be cut to expose the nozzle.
I think the caps are the same as the greens i removed. They are used greys and im led to believe they ran fine in the last car. Do i just drill the hole in the cap bigger?
I think the caps are the same as the greens i removed. They are used greys and im led to believe they ran fine in the last car. Do i just drill the hole in the cap bigger?
The easiest way is to pop the cap off and simply cut the end clean off with a sharp blade, then pop it back on.
They won't run correctly on a YB with the caps on.
The fuel pressure is also worth a check. 3.5bar with the reference pipe off the reg at idle
I see a lot of these threads and I just think that the Cossie needs the modern ecu, coil on plug and good injectors. I am so glad I went for ecu and loom swap and he it set up at mad. It is expensive but I hated all the misfires on my l8 setup. It hasn't missed a beat since.
I see a lot of these threads and I just think that the Cossie needs the modern ecu, coil on plug and good injectors. I am so glad I went for ecu and loom swap and he it set up at mad. It is expensive but I hated all the misfires on my l8 setup. It hasn't missed a beat since.
You can get Weber ecus to perform perfectly well. They have been doing so for many years, the issues with them are normally down to being poorly set up or having faults,
Changing the loom, sensors, ignition system, and making sure it has a suitable calibration is a good start to making it right, which is probably similar to what you had done. That might be one of the reasons yours is now right.
It's a valid point you make, but Give it 25 years and see if your modern ecu is still working, as the modern stuff is nowhere near as robust as the old Weber.
I do agree to a point though, there is better out there without doubt, but there no reason at the sort of spec mentioned here that the Weber can't perform perfectly well
Ive fitted a new fuel pressure regulator and its set at 3.5bar with pipe off and drops to 3bar with it on, plus ive got a pressure gauge fitted straight to it so im sure thats fine.
You can get Weber ecus to perform perfectly well. They have been doing so for many years, the issues with them are normally down to being poorly set up or having faults,
Changing the loom, sensors, ignition system, and making sure it has a suitable calibration is a good start to making it right, which is probably similar to what you had done. That might be one of the reasons yours is now right.
It's a valid point you make, but Give it 25 years and see if your modern ecu is still working, as the modern stuff is nowhere near as robust as the old Weber.
I do agree to a point though, there is better out there without doubt, but there no reason at the sort of spec mentioned here that the Weber can't perform perfectly well
Very true James...
Toby, Jon will come out in mine at some point so he will tell you how a sorted one goes.
On weber of course..
Yep had another look and there's a small cut on the rim and all looks good.
Ive done abit of google searching on overfueling. Faulty map and coolant sensors seem to be the main causes and i did change the map sensor when i fitted loom/ecu/injectors?
I am not saying they can't be sorted but it seems they need new looms etc and there are loads of threads on here of people chasing problems with Mis fires. It seems ancient to be working with points to deal with the spark.
I am not saying they can't be sorted but it seems they need new looms etc and there are loads of threads on here of people chasing problems with Mis fires. It seems ancient to be working with points to deal with the spark.
Cut the ecu plug off a 30 year old Weber loom and wire a new plug in it, and run a new ecu on one, you'll find the new ecus needs looms that work too, most of the problems would probably still be there!
My point is people think changing the ecu fixes hundreds of problems, but in reality it's all the other parts that go with it that are probably making the biggest difference, and the fact the new ecu will need to be live calibrated not guessing an off the shelfer will work, I'd put good money on it being much better!
You are dead right in what your saying,but I just look at the reasons why it's better afterwards, and it's not all down to the Weber being poor, look at all the other work that goes along with it.
I am not saying they can't be sorted but it seems they need new looms etc and there are loads of threads on here of people chasing problems with Mis fires. It seems ancient to be working with points to deal with the spark.
Rotor arm you mean, WS will give a stronger spark and less voltage loss. It also means you shouldn't have to run small plug gaps, but I have heard of quirks with it as well.
Hi all. Found some useful info on another website about how to check all the sensors etc with a multimeter on the main engine ecu plug.
Map was only 1.6v so swapped it for another and its still 1.6v?
Ignition trigger was around 3.6v and not 4.5v but is this because of the wasted spark?
Everything else checked out ok
Yes, as suspected the chip was wrong for my setup. Got in touch with the bloke i bought the ecu off and he told me it was chipped for an engine with a different comp ratio and bd14 cams, my car has standard internals. Bought a chip from brands hatch performance and its almost perfect. Taking it to my tuner and getting it done properly on a dyno
So it was a man made fault and not you're setup!
My friend is a mobile diagnostic expert and he says the 2 hardest things to fix are man made faults and following on from the fuse fairy (imaginary fairy that removes fuses to check them and replaces them back in the wrong terminal and creates more faults than they cure)
I have an l8 ecu on my 1990 2wd saph,it runs great with no misfires or hesitation,would like a new loom 1 day for peace of mind.
Right, took it to my tuner and before we put it on rolling road it was runnning rich.
Managed to get it to 0.9 by turning co2 screw 5 turns clockwise, so as lean as it could go, but on the rolling road it was 0.5 and the fumes where very potent so my tuner said it needs mapping properly, so we abandoned the test until he can map the chip correctly.
Took him for a spin init and it was fine at low revs and high revs when the turbo was boosting fully just hesitant mid range.
We both agreed that it was chucking in too much fuel too early before the turbo had chance to kick in.
On the drive home it was fine on the motorway as i kept the revs low and at low boost but once off the motorway, and driving about 50 mph, it started running rough throughout the rev range and struggled to build up boost but after a few miles it cleared itself?
Im thinking that it choked the plugs up due to the rich running?
My cossie runs 2.0 to 2.5% co on idle as per the manufacturers settings and what msd told me to set it to but it's only stage 3 so could be totally different to whatever you'rs needs to be?
My cossie runs 2.0 to 2.5% co on idle as per the manufacturers settings and what msd told me to set it to but it's only stage 3 so could be totally different to whatever you'rs needs to be?
I think the co2 readings where wrong on the rolling road. We first set the emissions on a different gas analyser used for mot before we put it on rolling road.
I think the co2 readings where wrong on the rolling road. We first set the emissions on a different gas analyser used for mot before we put it on rolling road.
Ah I see, never had mine on a rolling road, I'd shudder to think what they would find lol
30-04-2016, 09:27 PM
Cosworth 3dr misfire just before boost
