my 8v digi woes

Has the flywheel been skimmed or lightened and the tdc mark removed?
Every 020 flywheel I have come across has the TDC dimple cast in to it during manufacture.
It is the dimple next to the flywheel to clutch pressure plate bolt, to the right of the diamond chisel mark. The pic in this post shows it clearly.
When you refitted the vernier did the intermediate shaft rotate and knock the dizzy timing off. This is something that regularly occurs when the timing belt tensioner is slackened off. This could be the reason it ran poorly after adjusting the cam timing. Sounds like the ignition timing may have been a bit retarded when you restarted it.
http://www.clubgti.com/forum/showpost.php?p=1913640&postcount=6

 

i got my origanal fly on there. i had to make the mark next to the bolt to thr right of the diamond. i think it did move but id been moving it bwfore antway. once ita setup il let you all knoq what happens.
thanks again

neil

 

i managed to do my timing. was at about 4* so moved to 6. i couldnt set the co cause my analyser wont charge. but already theres a massive diference. better mpg and much better idle. but still getting jerking/ poss mis around 3k in the higher gears only. changed pluga again. no difference. havnt changed pick up pump yet. any ideas what it could be? thanks for all the help guys.
neil.

 

Rolling road?

Hi there mate.

I have recently had a full rebuild on my 8 valve gti, with a gasflowed head and Kent GS2H camshaft and vernier! I too have been having loads of issues and am taking my car into a reputable Rolling Road (eight week waiting list!!) near Chester next week. It really is the BEST thing you can do!!

Cheers Alpenweiss2

 

right, hello again, a little update for the tread.
i think im getting abit closer now. my jerking has turned out to be a misfire, but only really under light load that i can tell.
iv replaced ecu and tci with a spare i have, no difference, done all timing and co, got new plugs, fuel filter, air filter and coolent sensor, even though all my other bits are nearly new.

now it runs really well when i free rev it but it seems to be missing at idle slightly on all cylinders i think cause i cant pin point it, and under light throttle load.

so im drawn towards my coil before i have to take the head apart.
i measured the resistence on the primery windings, outside 2 posts i just got 0.00 on my multimeter, if i move the probe as rubbing the terminal i got all sorts of different flashs of numbers,lol. on the secondary windings it was steady at 3.41....

now haynes says that primary should be between 0.6-0.8 and secondary should be 6900- 8500 between negative post and ht tower....
my coil seems nowhere near those readings, this was off the car.

should i be replacing my coil???

thanks guys

 

There are two different coils for the TCI system and they have different resistances, so if it is the wrong one you have fitted this may be contributing to the fault.

early ones are 0.52-0.76ohms primary, 2400-3500ohms secondary

later ones are 0.6-0.8 ohms primary, 6900-8500ohms secondary

 

its the origanal pb green label coil on the car, with 130k on it i think.

so i couldnt just replace it with any coil?

thanks dan

 

coil replaced with brand new bosch unit. still seems the same but i havnt drove it yet.

what else should i be looking at for multi cyl misfire under light load?
thanks agin
neil

 

can anyone tell me how bad my idle should be with the 282 cam? iv never had a cammed car before.

glad i never wasted money on a rr session to be told its misfireing

 

A fast road cam on an 8v will give a lumpy idle for sure. A solid lifted 282 on an 1800 block will be lumpy and flat low down, with power concentrated at the top end.

Any tickover lumpiness should clear it's throat off tickover though.

You do realise the whole point of a rr session is to diagnose and sort running issues such as a misfire? Any decent rr should be able to sort this as part of a setup

With your light throttle misfire I'd suspect a fuelling or afm issue

 

ok, my update for the day.

today i changed my coil, cleaned my dizzy and rotor arm, sealed all the wireing with damp start, and reset my throttle stop.
didnt get the misfire on the way home.

plugged in my co machine and was on .40, so pretty lean,
unplugged cts revved 3 times, but wouldnt idle too well with adjustment right out,
so i advanced the timeing till it did, (no light here), got it to 1000 rpm with just a little jump now and again.
but now im amased, my co is steady, in setup mode.... it never has been since i got the car, so im guessing coil was on its way all along..

so now im getting the co to 1.8% my hc came down to 897ppm, lambda 1.037. hc did go up when the co went down when the fan cut in, but hey, things seem all good.
revved it 3 times to store it, plugged the sensor back in, and idle dropped to 800, co went down to 0.80, hc went up to 2300ppm.

i unplugged the cts again and raised the idle to 1200, revved again, plugged back in, back to 800 rpm
i just cant seem to raise my idle speed, which should bring my readings back in line.

question,,, can i set it up without putting into setup mode, reason,, i can adjust everything fine with it plugged in, nothing readjusts or anything to compensate. and if i raise my co up out of setup mode, my hc will come back down.
is that ok to do?

chris, my problom is paying twice really, at 250 and 200 mile round trip to stealth from london
i wouldnt want to have to do it twice.

once i see the potential with setting it myself, il want to get it set properly to get that bit more. as a so called mechanic i get no pleasure out of paying other people to fix things for me..
lol, i been a mechanic for 11 years but its easier to diagnose someone elses car cause its not my money they are spending if it doesnt work, lol,

but thanks

 

i went and picked up my timing light today, my timing was spot on at 6* ...

when i went out this morning the car felt like it had alot of urgency off the mark and my idle was pretty solid.... all the things this cam is not suppose to be.

so i retarded the cam abit, and i mean abit, very small amont and went out, hardly any power, so i advanced it back the smallest amount i could and it seems the power comes in around 4000 now, but not haveing any good marks on my pulley i dont fancy trying to move it the tiny bit needed, id like it to come in around 3000 as i have a standard limiter.

but the dreaded jerk is still there, but not all the time, but i can live with that for now as im thinking it might be internal due to the 6 months of crap running

so last question. jonny, what would be the ideal idle co for a 282 cam and pack c bvh with 421 manifold. and would it be worth me modding my afm?

thats 2 question but hey.

im a happy dubber at the momnt so will thank everyone thats had patience with me to get this far.

thank you

neil

 

ok wicked, my idle wont change whatever i do, only in setup mode, always goes back to 750-900 so thats not an option, idle co is set at 1.8 dropping to 0.80 when i plug the sensor back in, should i richen it up abit or leave it.

once i know its definitly all good i will make the trip to stealth.

but want to do my bike test first ;p


thanks again

 

It would benefit from being richer no doubt...as for how much, who knows

As for Stealth, vince can set up a modified 8v, so as long as it's in the ballpark he will make the best of it....

Its all well and good people quoting idle co figures, ignition timing and cam settings etc etc to you, but every engine is different so what works on one may not suit another..this is especially relevant to modified engines

An lc1 wideband lambda up the exhaust would help you sort the fuelling if you know what you are doing, but, with no disrespect, the amount of ongoing running issues you have had, and the fact you haven't yet sorted them, would mean a trip to a specialist with all the gear really would be money well spent and save you all the bother!!

Saves you tweaking things one way and the other with no ability to quantify the changes you are making...

Vince would know what ballpark AFR you will need to suit the cam, & can experiment with ignition and cam timing.

 

seems to be running spot on now. set cam to eqal overlap with a bit of advance, power seemed to come in around 2k and doesnt seem to tail off too much.

cant decide weather to wait till i do the 2.0 to get it tuned and chipped or do it before

thanks all

 

thought id change the title to suit the tread.

another question.
my oil temperature is getting upto 108 just driving normal and sitting in traffic.

what would i need to fit a oil cooler? thinking i could rig up a bike fan aswell with a thermoswitch for the fan to switch on when it gets to hot ;p

thoughts pls.

 

can anyone tell me what would cause the revs to hang up in traffic, and goes away most of the time with a blip of the trottle?

last thing, with the idle, if i want to set it to 1000 rpm would i put into setup mode and set it to 1200 or something so it drops down to 1000? or how does it work?

thanks

 

A hanging idle is most likely going to be a goosed ISV. Check all the isv and throttle microswitch wiring carefully too

For an oil cooler kit have a look at the rallydesign website...