rosie

saphire cosworth
running stg 3
greys
t34
3 bar
l6
etc...

car started with a slight missfire on low revs but cleard & has slowly got worse

i cleaned up all plugs other week & it ran on 4 & went like the clappers! ran sweet as a nut

i have orderd new plugs but they havnt arrived yet

i have:

removed all plugs again& cleaned them up & sheck they are all sparking (all good)
so thats plugs/leads eliminated

checked timeing (all good)

all injectors spraying fuel

tested map sensor on a mates car (good)

tried another CPS & it still ran the same

i have taken a video of the car running 2day & u can see how rich the car is running as it fills my unit with smoke in seconds!

if i unplug the TPS the missfire clears when revved (2nd half of video) but still runs lumpy on idle (like its on 3)
i have tested the TPS & have:
3.5 volts with no throttle (closed)
0.4 volts full throttle (open)

looking at these results it looks like its not right on idle & is over fueling?????
i have checked the flap is closed & it is

any other idears?????

cant be anything major as the engine is sweet & ran fine the other day!

wulliesxr4i

iTrader: (1)

thats plugs mate mines was doin the exact same thing bout 3 months ago,

rosie

well i have tried another 2nd hand set i had kicking about & it was exactly the same??

i did order some new ones but had to wait for them to turn up as was outa stock, should be here 2morra so will try them.

thing is im offshore for 2 months sat so wont get to touch it till end march after 2morra

rs2klee

coil pack ?

boost mad

iTrader: (8)

Try replacing the blue sensor on the back of your head.

The coolant temperature sensor and when they go it tends to run realy rich.

BigErn

While its running on idle try unplugging the injectors one at a time to see if it momentarily goes back on 4.

Let it idle and missfire, unplug number 1 injector for a few seconds.... listen to see if it stays on 3 cylinders or picks up on all 4 momentarily. If not then plug it back in and repeat with the next injector....

Ive had a couple of Sapphs do very similar and it turned out to be the injector wiring making a constant earth somewhere thus keeping it open all of the time.

Worth a try for 2 minutes messing about.

rosie

its dizzy not coilpack

rosie

yer will give it a go as sum1 else mentioned it & i have a new 1 kicking about

botters

iTrader: (2)

are all 4 lugs still on the crank pulley?

botters

iTrader: (2)

also your tps readings are wrong

rosie

tried this, number 3 didnt seem to make a diffence so tthought it was spark/fuel prob but plug is sparking & injectors are working as i removed rail & turned it over. all injectors are pulseing

will test wires to them 2morra thou

my mates old saph needed a new engine loom yrs ago as had failed

just looking for as much feedback as possible so i can spend a gd day on it instead of a hr here & an hr there

defo isnt a mechanical fault as was running mint other day & u can see by all the smoke how rich its running

im thinking its fireing/running on all 4 but its overfueling that much its running rough???

rosie

yes checked this 2day when done CPS

whats wrong with TPS settings???? i know it should be 4.5-5 volts on idle where mines 3.5?

botters

iTrader: (2)

have you played with the loom at all? when i put my engine back in mine i accidentley plug the iscv plug onto one of my injectors causing it to stick wide open, that made it miss and belch out smoke plus ruin Ł50 quids worth of fresh oil!!

botters

iTrader: (2)

have you tried turning the tps to get 4.5-5 volts?

BigErn

2wd throttle closed you should see voltage greater than 4.5V between pins 11 and 17 on the ECU

2wd throttle open you should see voltage less than 0.5V between pins 11 and 17 on the ECU

Have you checked the condition of the phase sensor also?

carl/saff

Was thinking myself , iscv sticking causing overfueling ......did happen on my saph .

Regular cleans with carb cleaner sorts the problem.

RS SHAUN

iTrader: (24)

have you tried turning it down on the ecu, (fuelling)

rosie

changed the blue sensor in head today, ran it up & ran loads better & thought it was sorted untill i realied the TPS was still unplugged, plugged it back in & its running like a nail again lol

no not yet as it looks a rite pain to get to the screws???

havnt played with the loom & correct wire is on the ISCV



i done it via pin 1 & 17 (1 is earth)

no not checked phase sensor yet but is on the to do list now

i will also try cleaning ISCV

no not touched the ecu as the car ran fine before

i will try replace all sensors when i get back, if no joy i will just have to take it sumwhere & get it sorted

LHD220Turbo

iTrader: (4)

my money is on the loom at fault. start it up and literally wiggle the loom and as many connections as you can

check the phase sensor though; its quick and easy to check.

Rollin Rides

I done the same thing, i was kicking myself of hours there so nearly the same colour till you look in the day light.....

botters

iTrader: (2)

oh tell me about it mate i felt a right twat lol!

botters

iTrader: (2)

i actually removed my throttle body as far as the plug would let me to enable me to adjust it, much easier than doing it in situ

Paul_RS

iTrader: (4)

Try brand new plugs first. As the missfire has gotten progressively worse thats where i'd start. Then leads, then dizzy car and rotor arm. Most of those are cheap to change, so best doing them before you get stuck into expensive/hard things.

KSA-Cossie

iTrader: (4)

Deffo sounds like plugs.

RSRoy

My brother had something like this last year. In high revs he had misfire's. Had changed the plugs twice with brand new ones, but only the 2nd set solved the problem.

rs2klee

was gona say the map sensor but just read you tried it allready!.

rs2klee

i ment this

http://cgi.ebay.co.uk/Group-Coil-Gen...item2559a100ef

just wonderd if you tried another coil, might be wrong plug gaps blowing out the spark?

weak spark maybe ?

rosie

yer i did try a std coil on it the other week as had a very simular prob on my escort cossie & turned out to be coil. but didnt make any differnce on this

rudeboy

iTrader: (2)

Check out my last page(s) of my car ... link below.

I was chasing a missfire for a while (got progressively worse) ... over-rich and terrible at idle.

Fixed it with changing the phase sensor (was visibly bad) AND the fuel regulator (still think this had a lot to do with it) as fuel had perished the sense line from the reg to the manifold due to an internal leak.

Hope this helps ... good luck.

Glenn_

iTrader: (1)

would the manifold air temp sensor cause running faults. Im on about the brown that goes in the side of the inlet manifold.

rosie

cheers i will give it a go when i get back in march & update

rosie

got home 2 days ago & had a play with this 2day:

turned out to be the fuel pressure regulator

turned it out 1/4 of a turn & its spot on now!

cheers 4 help anyway guys