fatscoobyfella

Anyone shed any light on this prob for me?
Car is 1989 8v.77,000 miles
Only mod is cams and OMP exhaust(only been told has hi lift cams..may not be 100% accurate).

Car generally sounds "wooly" on tickover and seems to have very light missfire.
Under boost and 4k+ RPM,car holds back,the odd cough,splutter and "seems" to missfire too.

Compressions all 150 Psi+
Cylinder leakage test..all seems fine.
Fuel pressure checked and adjusted.No prob..seems fine..
Gas tested,all Co2 readings fine,HC's fine as is o2 readings.
New plugs
New plug leads inc main HT
New coil
New Dizzy cap
New rotor arm
New throttle potentiometer
New crank position sensor
New map sensor
New Temp coolant sensor.
New fuel pressure reg.

ECU been removed and sent for check..No faults found..

Does have a knock sensor..not been replaced,but seems ok when checked with multimeter,and when reading live data from the ECU.

Injectors not checked or replaced...any known prob??

Anyone any idea's or should i throw it in the bin?

TIA

Paulo P

iTrader: (42)

Have you checked that it's not overboosting?

rossyboy

iTrader: (8)

No idea about the problem. What about some pics of the car

fatscoobyfella

Yea,checked its not overboosting,boost is currently set to 0.9bar.Cut defender is set around 1.2 i believe.
And to be fair,it doesnt really feel like the defender is coming in,doesnt feel like that kinda fault if ya get my drift..

As for pics,will see what i can do,its mettallic grey with 5 spoke Comp MO's on,full EVO 2 front on if thats any ggod to you

AllanB

Have you checked to make sure the timing belt is not a tooth out ?



AllanB

Paulo P

iTrader: (42)

Good thought. Mine did that

fatscoobyfella

Forgot to include that Allan..but yea..checked it and double checked it..did check vacuum in the manifold as well,pretty steady at 18-19in/mg..which does indicate that valve timing is correct..would have expected vacuum to be a bit lower if had cams in..or valve timing out...

Anyway..Sorry about forgetting that bit,but done so much lookin and messin with this motor,my brain is hurtin!!!!

Dunk

iTrader: (1)

If you've got this far, it has to worth getting the injectors cleaned & checked.

D

fatscoobyfella

I know Dunc...But there a trauma to get in and out,plus gaskets and quite a bit of labour..and £120 to get them checked...Just getting pretty ill with the thing and already got about 30 hrs..Guess another 6-8 wouldnt hurt eh??Ha ha...

Dunk

iTrader: (1)

Might be worth trying Keith at http://www.auto-integrale.co.uk/index.htm for a bit of advice, very genuine & saved me a fortune when I had a Coupe turbo.

D

rallycol

iTrader: (4)

If you end up with the head off ,I know someone with a full headset inc bolts and I'll be away from tommorow till 30/10.

Vegescoob

Checked all air hoses?
Minute cracks can open up under acceleration movement.
Some go porous with age.
Mate had this on his 2001 Vectra TD.
You say checked fuel pressure but have you also checked delivery?
Measured amount in given time.

fatscoobyfella

Not measured amount of fuel out of injectors but have elivery rate upto fuel rail..Well within spec,dont have a rollin road to check delivery rate under load,but fuel pressure doesnt seem to drop off significantly if at all under boost.
Car has full samco hosing and have checked all visible air pipes and vacuum pipes.

Dunk...cheers mate..will give hm a bell and see what he has to say..

Col..may end up with the head off like you suggest,just to be 100% if nothin else!!!
Will be in touch if need be when you return..

Cheers Fella's...

Vegescoob

Random thoughts now.
New leads etc OE, pattern or good upgrade?
I've known some pattern stuff to give problems.
Checked ignition under load?
Lead breakdown etc.
Stupid thing like all plugs tight.
Samco hoses tight? They can extrude and need regular tightening.

fatscoobyfella

Plug leads are magnacor silicon blue,have checked ignition under load when free reving with a picoscope.KV's actualy look slightly low,but not significantly i feel,i opened the plug gap slightly from standard so this may well be the cause.I opened up the gap,just to make sure the flame wasnt bein "blown out" under boost,wherever i set the plug gap there was n change in the cars behaviour.NGK plugs BTW.
Most of the Samco's have been removed and checked,and tightened and then all remaining hoses tightened,many of the vacuum hoses we have just renewed.

Just from my view,i cant see it being an ignition fault,it has had everthing new..and upgraded,inc the ignition amp ,which i forgot to list on the original post.All voltages to and from all ignition system componants have been checked and are perfect,nothin at all slightly suspect.
Its a head scratcher for sure!!!

Vegescoob

More thoughts.
Wiring loom and all connectors.
If original may be bit of corrosion in places check them all.
Problem once was wires inside a loom, insulation had got burnt during some welding and cables shorting giving rough running. Confused signals.
Then exhaust, check whole system to make sure no small leaks that could draw air in.
If not, does sound like head off, even though figures ok, may be a slightly bent valve/valves. Of course these days we don't expect to decoke but you never know.
Cam lobes all ok? Not worn. Presumably these cams are timed right, vernier pulleys?

fatscoobyfella

Im suspecting it will be a bit of rot in the loom somewhere too.Cams look visually ok and on standard pulleys,not verniers.
Think im gonna pull the head off and have a look and send the injectors away to be checked,see where that leads us.
Didnt look at it anymore more today,had my head up my bumhole with a missfiring TVR Cerbera most of the day,but seem to have sorted that one!!

Vegescoob

Well at least it's a modern classic.
What's cold start system on these, idle air valve?
Known them go sticky. Carb cleaner to do.
Plugs, you say NGK. Heat range? They aren't one of these "fussy" engines that like plugs from their own country are they?

matthefezz

does it run an atmosperic as our evo Vi wont idle or run correctly with a dv ,
another is the fuel filter has it been changed and check that the gaps on the plugs are correct , other than that its a case of take it all off and re-fit , if its that pronounced it could be a cam problem as the lancia beta's were abit prone to losing a cam lobe too although i know they were 16v it would explain the missfire?
cheers
matt

fatscoobyfella

Plugs...Did have Magneti Marrelli ones in that were pretty new,but decided to change them to NGK as ive never had a problem with NGk plugs,also moved up the heat range by one clik,just to try and cover my bases.Does have an air idle valve,similar to early beemers in design,again mate i checked it and its clean as a whistle and works well,returns to idle perfect and no hunting or sticking..

Fuel filter has been changed,just for the sake of it really,but all fuel pressure readings taken before and aft new filter change,made no discernable difference.

Car does have a Bailey piston DV that does vent to atmosphere,but tried the original that was in the boot,this dumps back into the intercooler/inlet pipe.Again,didnt alter running and didnt cure prob.
Also as said in previous post,checked the cam lobes visually.Seem fine with virtually no wear.I may check again,as i only checked them when i was checking the valve timing,i removed the cam covers to actually see the position of the cams,just to make sure non of the cam pulleys had "spun" on the woodruff keys.
Again..no banana for me!!

pacenote

Some things to try:

Check TDC sensor gap, should be 0.4mm
Replace NGK plugs with standard ones eg Bosch WR6 DC

Check condition of hoses inside fuel tank that run from pump to tank outlet as these can become porous with age and cause drop in fuel pressure under load. Access pump via hatch under rear seat

I was also going to say replace coil and fuel filter but I see you've already done that

Also give John Whalley a call 01279 654181

HTH

fatscoobyfella

Thanks for all info...

Pacenote..Not convinced about plugs mate,as this would be the 3rd set in little mileage..And never had a prob with NGK in any application,so im loathed to try any other really..

Interesting what you say about fuel pipes..i aint checked that at all,like i say,we aint got a rollin road to check fuel pressure under load.We did try rigging up the fuel pressure gauge so we could see it as we drove,was a bit hairy,as boost ,cough,bang happened and tried to look at gauge at same time!!
Will look and investigate..you just might have somethin there.......

Oh..set TDC gap at 0.4,was 0.6 as it came and bolted up to the bracket.!!

pacenote

I know what you mean about the plugs it's just that the standard plug is a good place to start with standard engine running standard boost and I know that John ( whalley) has had good results with the Bosch plugs - I personally use NGK plugs (B8EGV) but thats on a 16V (Evo1 ) running 1.2 Bar of Boost

Hope you sort the problem

Rob16v

Have you visited the Delphi Evoforum?

http://forums.delphiforums.com/evoforum

There's an extensive FAQ section on there, as well as a lot of knowledgeable owners. Have you checked the Throttle Position Sensor (TPS) - it's a common source of missfires on Grales


Rob (Evo1)

fatscoobyfella

Hi Rob,

Thanks for the suggestions..will have a look on there and have a snoop around.
Have already fitted a new TPS mate...

Vegescoob

Any progress with the Italian Stallion?

Scooby-Doo

Wouldn't it need a remap for high lift cams ?

Jamo

iTrader: (23)

cant be arsed to read it all, but have you got an aftermarket airfilter on it? with the problems of acceleration, could it be a fuel/air mix problem?

if its been covered sorry, too much to read through

fatscoobyfella

Car is sorted.........It was interference coming from all engine components into the main engine bay wiring loom.
Fix was ......covering loom and ECU in tinfoil and testing car as in previous posts..

Car was great,must have been bad unshielded wire in the loom picking up interference.had it once in a 355 spider,which is very similar in configuration,ignition wise..

Gonna delve deeper and do 100% fix when i have some time...
Ta for all the suggestions fella's.......