Engine Troubles

[ECR 033]

Vehicle: 1989 Skyline GTR

Problem:

- Engine wont rev past 4500rpm - 5000rpm starts holding back and missing real bad (its worse when its hot starts doing it at about 3500rpm)

- it revs upto the redline when in neutral, and idles fine, the revs drop (slightly) when you first touch your foot on the accelerator.

Done:

Checked and cleaned AFM's

Cleaned and checked plugs (NGK Irridiums)

Pulled out coilpacks and sealed them with high temprature silicone.

checked all plugs and wiring

Been at this for 3days trying to work things out... im out of ideas, it seems as tho its a coil-pack break down but who knows.

ANY help appreciated (A.S.A.P)

===========================================================

UPDATE:

pulled off the CAS and found the shaft was broken....so i replaced it with a new part...and it still wont fire...checked injector pulse again and it still has nothing.

checked for ECU error codes and it flashes up *55* - which means everything is all good.

im now lost as to what the problem is... what pin on the ecu controls the injector pulse? and is there a relay to check or a fuse, or antoher earth wire?

Edited January 29, 2007 by -GODZLA-

[DVS JEZ]

do you have any mates with the same car?

you need to try swapping coils, igniter etc,

i know you said you cleaned plugs but how old are they?

have you gapped them down to .7ish

[Race_Bred]

sounds like a fuel pump problem

[DVS JEZ]

sounds like a fuel pump problem

2nd that actually, theyre getting old now

[700HP-GTR33]

Have you tested fuel pressure?........

If it ain't the above as mentioned I am guessing it could also be the injectors.

[ECR 033]

Ok,

Car died on me yesterday, and will now not start, spark and plugs seem fine too me (did as mentioned in first post.) also pulled a coil pack out and turned the engine over and it sparked.

fuel pump seems to be fine, (havent got anything to check the pressure but it pumps out flatstick)

also the pump keeps running and dosn't switch off (shouldn't it turn off once pressure builds up in the fuel rail?). - also pump is a little noisy.

i also thought it could be the little fuel regulator at the end of the fuel rail, i thought it may be stuck open and just feeding back to the tank.

- so i took the return pipe off to see if it keeps pumping out... but it doesn't pump out when fuel pump is on...it only does it when i try to start the engine.

also could it be somthing that controlls the injectors?

hope that makes sence to someone?

cheers for any help.

Edited January 28, 2007 by -GODZLA-

[Race_Bred]

i know you said you have checked fuel and spark, but is this prior to it stopping or have you checked it now that it has stopped also?

[ECR 033]

i know you said you have checked fuel and spark, but is this prior to it stopping or have you checked it now that it has stopped also?

yep this is once it stoped (checked it aobut 20 mins ago)

cheers

[Race_Bred]

yep this is once it stoped (checked it aobut 20 mins ago)

cheers

if you want to check that it is not low on fuel pressure, try clamping the return line and see if it will start, i assume the spark plugs are not drowned in fuel? if they are then it wont fire

if the spark is good and fuel supply is good it may be worth while checking timing marks, perhaps the belt has jumped a tooth?

[SECURITY]

if its not your fuel pump id be looking into your actual coil packs. clean them out lightly with a dremil drill or some steel wool.

[ECR 033]

if its not your fuel pump id be looking into your actual coil packs. clean them out lightly with a dremil drill or some steel wool.

ok iv tried a new fuel pump, and it doesn't help.... but just realized i can hear a relay clicking off after 5 sec and it turns the pump off ... the relay doesn't give the pump time to get fuel to the engine...so what controls

this relay is my new question?

cheers to everyone's help so far

[Race_Bred]

ok iv tried a new fuel pump, and it doesn't help.... but just realized i can hear a relay clicking off after 5 sec and it turns the pump off ... the relay doesn't give the pump time to get fuel to the engine...so what controls

this relay is my new question?

cheers to everyone's help so far

some pumps do that, some pumps dont, the clicking would be the fuel pump relay, if you had a problem with that you would have no power at the pump

[Simon-S14]

disregard the fact that the pump might not be running when the ignition is switched on and check to see if you have actual pressure in the lines when the engine is cranking over. if you do, this will effectivly rule out the pump.

Get an LED test light and test the injectors to see if they are pulsing while cranking.. which will also rule these out. Tehn thats just about the fuel side of things.

One thing to check that no one has mentioned is the Crank Angle sensor.. if this is failing it will cause the crazy missfires at revs... and if it has failed it wont start at all...

other things to check would be AFM's, Timing belt and timing in general, may have jumped, Ignitor for coilpacks, power to coils, and packs acctually firing,

[ECR 033]

ok, i just hard wired the fuel pump to the battery and and it now pumps fuel to the rail...but the fuel is constantly running back to the tank... so its got plenty of pressure in the rail...so i pulled a spark plug out and it was damp with fuel. so i think the regualtor is fine...so im confused as to why it wont start...spark is there and so is fuel..........................................................................

EDIT: It has a new timing belt on it as the engine is fairly new

also how will i know if the Crank Angle sensor is buggerd or is it out of place maybe?

cheers

Edited January 28, 2007 by -GODZLA-

[DVS JEZ]

if the crank angle sensor is buggered you wouldnt have any fuel or spark UNLESS:

the crank angle sensor has broken its shaft and spinning intermittantly and firing etc but at the wrong time, i had this problem with my car (front cover removed but crank sensor bolted up) snapped the shaft,

also check the keyway at the end of the crank angle sensor spline isnt broken

[ECR 033]

if the crank angle sensor is buggered you wouldnt have any fuel or spark UNLESS:

the crank angle sensor has broken its shaft and spinning intermittantly and firing etc but at the wrong time, i had this problem with my car (front cover removed but crank sensor bolted up) snapped the shaft,

also check the keyway at the end of the crank angle sensor spline isnt broken

I don't think its the CAS tho, cause as i stated in post one before the car stopped it was missing under load at 4500rpm and when it got hotter, unless they do the same thing when they are on the way out? i had it of earlier and it seemed ok

so in guessing for now injectors (somehow) or ignition module

Edited January 28, 2007 by -GODZLA-

[ECR 033]

ok, i assusmed the injectors were working as the plugs were a little damp, but i checkd for injector pulse and there is none at all.

so would this be cause of a ground connection or loose wire or somthing (it wouldn't be a fuse as i said its somthing that was breaking down slowly) and now has shit itself.

cheers for any help

[ECR 033]

ok,

i pulled off the CAS and found the shaft was broken....so i replaced it with a new part...and it still wont fire...checked injector pulse again and it still has nothing.

checked for ECU error codes and it flashes up *55* - which means everything is all good.

im now lost as to what the problem is... what pin on the ecu controls the injector pulse? and is there a relay to check or a fuse, or antoher earth wire?

cheers

[Race_Bred]

what are u checking injector pulse with?

they must have been pulsing to let all the fuel to the plugs,

if the plugs are soaked, then it will not go, you will have to replace the plugs

[MR331307]

The injectors and Ignition have seperate fuses in the harness.have to check each one im unsure which is which

make sure the timing is not over advanced or retarded.Skylines dont run at certain points.Did you install the timing belt correctly

is it series 1 or 2

They have a earth at the rear of the coil pack on no 6

make sure this is put back on.

have you tried jump starting the car

have you got comp in the engine

Edited January 29, 2007 by MR331307