Loving the black gril and of course the rest of the car ...... So close now
Loving the black gril and of course the rest of the car ...... So close now
More babysteps forwards today. Got all of the replacement Bosch 803 injectors fitted and the car runs as smoothly as you could want on all 4 cylinders now.
Still have a problem with an erratic, high idle speed, though no longer dropping from 4 to 3 cylinders, which is better, I suppose!
It will fire up and run at 1800-2000rpm at idle, hunting up and down occasionally. It doesn't seem to drop at all. The throttle cable is now disconnected, just in case it was pulling open slightly, so it's not that, and leaving the ISCV unplugged didn't make a difference either. No air leaks that we can tell.
The possibilities now are:
ISCV itself
TPS (please not be this - it's a pig to get to!)
CO mixture screw on the ECU
The ISCV upon take it out of the throttle body shows it to be absolutely seized solid, so that certainly wouldn't help, and probably explains why unplugging it didn't make a bit of difference what so ever! I'm not sure if the position it's seized in would cause it to run a high idle or not though. So, that's now one new valve ordered.
Still could be TPS and/or mixture screw, possibly also fuel pressure - I don't have any easy way of testing for CO or fuel pressure at the moment.
One more problem is that it seems to run very hot - my temperature gauge gets to 105 and it was only shortly afterwards that the thermostat opened. I've been having to switch the fans on manually to keep it cool. So there might be a thermostat problem and/or a water sensor or engine coolant sensor problem. May have to swap them out at some point (there were new though, so it's odd). Also my oil pressure and oil temp gauges are not working, so that's another thing to investigate.
Fun and games.
Quick update - Since I don't want to drive the car anywhere before getting the CO, mixture and fuelling at least vaguely right, I've ordered a fuel pressure testing kit (it will tee in to the fuel line just before the fuel rail and let me set the fuel pressure using the original Cossie regulator) and a basic exhaust gas tester (a gunsons gasmeter). I know they're not great pieces of kit, but even it it's a couple of percentage points out, that's probably better than the car being so rich it washes the bores or so lean that it melts a valve on the way to the tuners. I haven't got a clue what the fuel pressure or mixture is at the moment - from what I've read from the documentation that MSD has put out, getting the idle mixture within a reasonable range should be good enough when using closed loop fuelling - then needs to be adjusted correctly on the rollers.
Will be looking for a knowledgeable Cosworth tuner in the north east in the next month or so. I recall there being someone up in Newcastle, but can't remember who it was now, but there's also Motoscope at Northallerton who seem to have had a good reputation for a long time.
Also getting some minor jobs done today while waiting for the engine bits to arrive - already got the handbrake gaitor fitted this morning, as well as the last bungs and grommets in the boot - almost forgot about the one directly beneath the central support for the rear panel; that could have been a bit embarrassing to find the boot full of water!
Probably do the last little bits of electrics this afternoon (power feed for dimming rear mirror and headlight warning buzzer). Minor jobs, but stuff I can do without disturbing anything else. There's also the boot carpet to make, if I get time!
Handbrake gaiter fitted to match seats and gear lever surround:
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Haven't been on here in a while... Wow Great progress...!! I'll pop round when I'm home next to take a closer look if you don't mind...?
Replaced the ISCV valve and checked the fuel pressure - it was a fraction too high (around 3.8bar with vacuum disconnected, so I've dropped it to the reccomended 3.5bar,), neither change seems to have made much difference to the high (~1800-2000rpm) and erratic idle speed.
In the video you can hear the idle going up and down - that's not us blipping the throttle.
Any ideas? Is there another sensor or failure that would cause this behaviour?
where did you get your ICV from..? some are made with a crappy week Chinese spring inside probably destined for bic pens...
If you have and OEM spring change it over... That's if its not an OEM ICV.. I hope that makes sense...
Cheers Wayne. Will take a closer look at the spring.
Some progress made today however; found that the previous owner of the engine had bodged the idle screw on the throttle body. It's supposed to have 2 o-rings sealing it, well, it had about half a one, with the rest taken up with silicone sealant. So that didn't help. Managed to get the idle, without the ISCV plugged in, down to a nice, steady 900rpm or so. It still drops and hunts every so often, but it's far, far nicer now:
Also reset and checked the CO - courtesy of the cheap Gunsons gasmeter it's idling, hot, with CO between 0.5 and 1.0%; supposedly about right for a Cossie closed loop setup.
As soon as we plug the ISCV valve back in the idle shoots up to ~2000rpm and it's up and down all over the place. Unplug it and it settles down, right as rain, at 900rpm again.
One thing that remains to check is the TPS. Apparently these need adjusting to get the sensor in just the right place, otherwise the ecu doesn't know when you're at idle on the throttle stop and can trigger the ISCV. That might just be the remaining issue now. We will have to check that tomorrow now.
Can get the idle down, but the ISCV valve is still being triggered, constantly in a cycle of raising the idle and then dropping off again; you can see it revving itself by around 400rpm every few seconds in the video:
This is proving to be extremely annoying.
Tried looking for air leaks - can't find any.
Tried adjusting the idle bypass screw - no effect other than at the extreme ends of its adjustment; where it either stalls or shoots up to 1400rpm (doesn't seem right to me!)
Checked the TPS voltage range - 0.1v at closed, 4.65v at wide open. That seems to be within tolerances, though I've had one comment that the closed voltage is too low.
All the right sensors are connected up and plugged in to the right connector in the loom.
Up to temperature and without the ISCV valve plugged in and it runs like a sewing machine and it revs as smoothly as you could ask for, no hesitation or anything like that. But starting it from cold without the ISCV and it's really sluggish and constantly wanting to stall, as you may expect.
You got a ghost in your garage or what. Must be frustrating as it's so close
The first time I was recording it and it was going up and down my dad had been playing with the idle adjustment screw and I thought he was opening the throttle plate himself. Nope, turns out it was the ghost doing it.
Before I start going through and replacing all of the new sensors, one by one, I've got a possibility of resetting the TPS again due to that one comment about the closed voltage being too low. So that's worth a try. Still, that's going to have to wait until next weekend now. Argh! It's annoying when there are lots of little things like this to try and solve and not having the car right near me to just go and try something out (it's with my parents about 20 miles away).
so close..will be something simple...unfortuantly i have no idea what...but thank you for sharing .it will invaluable to someone with the same problems...love the car...cheers mark
What throttle position sensor do you have? It will either be a PF01 or a PF09, then depending upon what ECU you have you may find the ISCV issue. The PF01 goes open circuit when it's fully closed, and the PF09 has to be within a certain resistance thus voltage output at closed throttle.
Unfortunately if you have a L6 ECU and a PF09 you may have to live with the ISCV disconnected.
Yep, the reading I get is 0.07v closed and 4.65v fully open. It should be okay, but I've had one or two comments that the closed voltage might be too low.
According to bigturbo.co.uk the P8 does a reset/purge cycle at power-on, but the L8 doesn't do the same, unfortunately.
Last edited by MegatronUK; 31-05-2017 at 22:27.
It's literally brand new. Only been in the car since this Saturday. The last one was seized solid and this was ordered as a replacement about a week ago.
The new one don't work well if you have the old iscv change the springs over , the trick with the new ones is to elongate the spring to the same as the one in a genuine one , joe @ gs Motosport did some for anembo , there are 3 different ones I've seen as well
Couldnt tell you without looking
quick question.. Im looking for a lower profile for my 15" wheels yours look like Toyo Proxes what size did you go with and where did you get them from.?
Hi Wayne, yep, Proxes T1-R. Front is 215/45x15, rear is 225/50x15. I just got them from Demon Tweeks, I usually use Blackcircles, Mytyres or Camskill for tyres, but DT ended up the cheapest for the Proxes.
I did initially have 225/50 all round, but on full lock they were catching on the front outer edge of the front bubbles. Going from 225/50 to 215/45 drops the overall tyre height by a good inch, which was enough to clear.
So we're no further forward. Swapped the internal springs over from the old idle control valve to the new one - no difference. Adjusted the TPS (throttle body off job, what a pain) to be 0.34v closed, 4.5v wide open - no difference.
Still hunts and still surges to 2k now and then with the iscv connected. One thing which is bugging us is that the idle bypass screw just doesn't seem to make much difference at all, until right at the end of either direction of travel.
I think next on the list is a new idle bypass valve and a new set of engine sensors. Pretty much at the end of the options now. Other than that, it's going to be a case of finding someone who is an expert on these engines to come and take a look - it's probably not in a state where we can finish it and drive to get it tested.
You can only alter the idle speed with the car warm, and the ISCV disconnected, believe it should be set to 900rpm. Careful you don't crack the throttle body by winding it in too far as they break easily.
Are you sure that it doesn't have an air leak, if the bypass valve isn't having much effect, and the ISCV makes it go wild, that's what its sounding like. A very easy way to test this is to get the engine to a point where all the inlet valves are closed, then take the hose from turbo to intercooler and block it off (I found that my aluminium coffee cup was a perfect fit ) then using the vacuum line that goes to the fuel pressure regulator and used an air line to pressurise the entire inlet system. I was amazed as hoses that I thought were tight using Mikalor clips, were leaking air everywhere. Once all sealed up I pressurised to 3 bar. If you have not done this I highly recommend it.
I made up an adapter that fits into the turbo intake n used compressor to check for leaks :-) ur b surprised at what u find leaking 🤔
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Here was my 'adaptor' Ian I did the same as you, blocked it off on the inlet to the Turbo, just the OP has a filter directly on the turbo...
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I like the oil check sticker!
Following the advice on the spring in the ISCV dad completely disassembled it:
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The top one is from the new valve, bottom is from the old. The old spring though shorter is also much much stronger.
Swapped both over and found it made no difference. On the advice of a couple of folks on Passionford we stretched the original spring out - the advice was to ensure that the piston sat approx 2mm down inside the ISCV; with the springs as standard it was way, way down inside, so clearly they are both wrong and far too short. I suspect that the original owner had idle problems and that resulted in the ISCV being seized (it looked bent the first time we removed it) as well as bodging the idle bypass valve up with silicone.
With that done, it seems to be running better, it doesn't go nuts when you plug the ISCV in and it also seems to settle down a bit more - still hunts a bit, but not like before. The idle bypass screw still doesn't do much (engine warm and ISCV unplugged it only makes a difference all the way in or all the way out - the biggest section of adjustment in the middle does absolutely nothing), but we've now got a new one to replace it.
So, tomorrow we try the idle bypass screw and also replace the ECT and ACT sensors. I honestly don't think it's an air leak problem - we've used plenty of start plus spray around all the joints and inlet manifold and found no change. Hopefully the new idle screw will fix the last of the idle problems.
Last edited by MegatronUK; 09-06-2017 at 20:12.
So not really any further forward today. The positive outcome is that the ISCV valve operation now seems to be as expected - raises the revs when starting from cold, eventually settling down to a nice 800-900rpm after 30 seconds or so, but the idle is still a big problem.
The problem is as the car starts to warm up the idle gets more and more erratic, dropping out to 400-500rpm perhaps 5 or 6 times a minute, and occasionally dropping so low that it stalls. The rev counter bounces up and down when it does this, but much more aggressively than the actual engine revs would seem to indicate. With or without the ISCV valve the idle gets erratic; with it connected it does activate enough that it saves the car from stalling more often, but it still doesn't catch it all the time. Without it connected it stalls much more often.
And the idle adjustment screw does absolutely nothing. This is with a brand new brass screw and seal from Graham Goode just fitted, too. Yes, this is adjusting it with the ISCV disconnected and fans/lights switched off.
I think things are at a point now where we just can't do anything more without more diagnostic tools. Even being able to see what the actual engine rpm and temperature sensors are reading, without relying on external gauges.
Is there any other option than the IAW data logger? Seems expensive (£280) for a software solution to accessing something that is already present in the ECU.
Last edited by MegatronUK; 10-06-2017 at 23:14.
Is the phase sensor new inside the distributor base ? Mine did things like this when hot but u never know 🤔
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The phase sensor and tps are the only original sensors that are left. The phase sensor looks okay and is gapped according to the workshop manual specs (and as near as dammit as we could set it to number one piston being in the right position), but no, it's one of the only sensors that isn't new.
I would still positively pressure test the inlet... If the phase sensor is broken it just wouldn't start.
There is a very good checklist of meter readings you can test at the ECU multiplug, this was not written by me, but I have used it many times. As long as you have a decent multimeter... Some you will know work fine as you have spark etc etc
1) Ensure ignition is OFF...done
2) Remove rear of ecu plug cover and insert plug back into ecu...done
3) Turn ignition back on (do not start engine)...done
4) MAIN POWER CHECK: Check for DC voltage of at least 11.5V between ecu pins 19 and 20...12.28
5) REFERENCE CHECK: Check for DC voltage of around 4.8 to 5.2V between pins 11 and 30...4.94
6) MAP SENSOR CHECK: Check for DC voltage of approx 1.8 to 2.5V between pins 11 and 15...1.55!!!!!
7) THROTTLE CLOSED:
4x4: Check for DC voltage less than 0.5V between pins 11 and 17...0.15
2WD: Check for DC voltage greater than 4.5V between pins 11 and 17.
8) THROTTLE FULLY OPEN:
4x4: Check for DC voltage greater than 4.5V between pins 11 and 17...4.75
2WD: check for DC voltage less than 0.5V between pins 11 and 17.
9) Turn ignition off, unplug ecu, and turn ignition back on (don’t forget immobilizer if fitted) ...done
10) CRANK SENSOR: Check resistance between pins 3 and 4 between 300 and 1200 ohms...633
11) CRANK SENSOR: Check AC voltage on pins 3 and 4 while cranking engine - should be at least 2V. 0!!!!!
11) PHASE SENSOR: Check resistance between pins 5 and 23 between 300 and 1200 ohms...778
12) PHASE SENSOR: Check AC voltage on pins 5 and 23 while cranking engine - should be at least 1.5 - 2V. 0!!!!!
12) INJECTOR: Check resistance from pins 18 to 20 should be 2 to 5 ohms...2.7
13) INJECTOR: Check resistance from pins 35 to 20 should be 2 to 5 ohms...2.7
14) INJECTOR: Check resistance from pins 33 to 20 should be 2 to 5 ohms...2.7
15) INJECTOR: Check resistance from pins 32 to 20 should be 2 to 5 ohms...2.7
NOTE: INJECTOR TESTS MAY NEED MAIN RELAY ENERGISED ON L1 and L6 ecus (link pins 1 and 10 first)
16) IGNITION TRIGGER: Read voltage between pins 24 and 25, should be at least 4.5V. 3.8v so a little low but checked to the negative on the battery aso and the reading is the same...3.5!!!
17) IGNITION TEST: BEWARE DANGEROUS VOLTAGES ON PLUG/COIL LEADS.
Quickly link pins 24 and 25 on and off this will FIRE the ignition coil. Rotate dizzy by moving car in gear to point rotor arm at one plug lead and remove spark plug (earthing it on chassis or engine) to see spark. Try for each plug in turn. Or remove king lead at dizzy and place end within 1 centimetre of earth to see a big spark...didn't do this as have spark on all 4 plugs
18) Place a temporary wire link from pin 1 to pin 10 (energises ecu power relay) - you should hear a click...didn't do this as relays click with ignition so presume ok
19) Quickly link pins 19 to 28 to test fuel pump runs...pump primes on ignition only for a second but runs constant while cranking. Think it's normal.
20) COOLANT TEMP: Check resistance pins 29 and 11 for 800 ohms to 5000 ohms (depends on temp)...6200!!!
21) CHARGE TEMP: Check resistance pins 31 and 11 for 800 ohms to 5000 ohms (depends on temp)...6170!!!
Also what plugs are you using in it?
It looks like we've found it. Thanks to one of the forum members on Passionford (helpfully someone who used to work for MSD), we followed the suggestion of unplugging the lambda sensor and the car now runs perfect.
It idles from cold with the ISCV valve connected at around 1200rpm, settling down to an idle of just over 900rpm, set by the now working idle adjusting screw (obviously when the ISCV is unplugged).
No self revving, no surging, no erratic rev counter behaviour.
So, could either be a faulty O2 sensor (though it's brand new), or faulty/incorrect wiring. But at least that's something we can now check.
Feels good when you have a way forward and that's what forums are all about, helping each other. She has come a long way and is looking good so well done and keep it up as not much left now
Yeah, it was so odd with the idle adjust screw - the ecu must have been continually adjusting the fuelling when we were trying to set the idle, with incorrect readings from the O2 sensor.
Probably makes sense once we've got the O2 sensor connected back up again to recheck the mixture screw on the ecu and do another exhaust gas test.
If this sorts its, and I'm sure it will, hopefully we'll get the bonnet on shortly and do the last remaining bits and bobs fixed, ready for an MOT.
Still got a problem with the idle on the car
Starting, and running while cold or before getting up to temperature is spot on, but when it gets gets hot it starts to go rough again. I've bitten the bullet and got a copy of the RPLabs IAW diagnostic monitor software on order. Hopefully that will datalog everything and when can spot just what triggers the rough running.
Anyway, with that put to one side we've got a few more fiddly things out of the way - suspension and steering all now set:
- Toe in approx 1/16 or 2mm.
- Camber set to somewhere between -1.5 and -2 degrees.
- Caster set with the eccentric top mounts set as far back as possible (didn't measure this, but both sides identical).
Alignment came courtesy of a Dunlop caster/camber/kingpin gauge set from the late 60's/ early 70's - so it is period correct for the mk1!
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Pretty old kit, but hey, it still works!
Also swapped out the temperature sender in the side of the head - the original Cossie one doesn't run the Stack temperature gauge properly, as we've found. It was regularly topping out at 120'c on the gauge, but a infra red temperature probe was only seeing 70-80'c at the thermostat housing and a similar temperature around the radiator. If anyone else is building up a Cossie for a mk1 or mk2, one bit of advice is decide what auges you want to run and fit the sender before you put the engine in the car. What a pain in the arse! Ended up having to remove the starter and dipstick tube to get enough space to get it swapped over!
Found a small oil leak from the back of the T5 box, so it looks like a new rear oil seal is needed.
On top of all that, dad and I had a real head scratching moment when it came to getting the car out and on to the lift this morning to sort out the alignment. The flippin thing just wouldn't start! Spent around 15 minutes cranking it, charging the battery, unplugging and re-plugging the ISCV valve, checking the base mixture setting... everything you could think of.
... and what was the actual problem?
No fuel left in the tank
Still, that's £20 it's burned through, just sitting in the garage, probably no more than an hour of run time!
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