| Author |
Message |
Phil Hughes (Ferrarifixer)
Junior Member
Username: Ferrarifixer
Post Number: 96
Registered: 7-2003
| | Posted on Sunday, August 24, 2003 - 6:38 am: | |
Take your car to any well equipped service station and hook it up to an oscilloscope.
All your spark traces will be clearly displayed for you to identify any rogue high KV readings. You can then identify which cylinder from the firing order (15374826) and save hours of speculative diagnosis.
You may need to put it on a rolling road to load it in order to get the misfire happening, but that should still be fairly easy to find??
QV suffer from dist cap, rotor arm, leads and extension problems if neglected.
The red plug extensions are resistive, the black ones are not. All Euro QV's should have the red ones, not sure of US. But you say you have a direct coil system???
Check the plugs too. Throw any champion in the nearest garbage. Fit NGK BP8 EV(or EVX). |
Dirk Rabenschwanz (Dirk)
Junior Member
Username: Dirk
Post Number: 56
Registered: 4-2001
| | Posted on Sunday, August 24, 2003 - 6:24 am: | |
Brian,
why do You mean that comes from the spark plug extenders ?
Did You have also such problem ?
Dirk |
Brian stewart (Eurocardoc)
Member
Username: Eurocardoc
Post Number: 424
Registered: 11-2001
| | Posted on Saturday, August 23, 2003 - 7:03 am: | |
Three words- plug wire xtenders. IMHO |
Dirk Rabenschwanz (Dirk)
Junior Member
Username: Dirk
Post Number: 55
Registered: 4-2001
| | Posted on Saturday, August 23, 2003 - 2:01 am: | |
My car is a 84 QV.
Thanks
Dirk |
Malcolm West (Ferrari_uk_tech)
Junior Member
Username: Ferrari_uk_tech
Post Number: 55
Registered: 7-2003
| | Posted on Tuesday, August 19, 2003 - 8:15 am: | |
Dirk
This might help,(www.auto-solve.com/mech_inj.htm) there is lots of info on this site, you will need to have a fuel pressure guage and the adaptors to fit the car. The fuel pressure is measured from the "outer" union of the warm up regulator.
MW |
Malcolm West (Ferrari_uk_tech)
New member
Username: Ferrari_uk_tech
Post Number: 49
Registered: 7-2003
| | Posted on Tuesday, August 19, 2003 - 3:13 am: | |
Dirk
What model and year is your car ?
MW |
Dirk Rabenschwanz (Dirk)
Junior Member
Username: Dirk
Post Number: 54
Registered: 4-2001
| | Posted on Monday, August 18, 2003 - 12:42 pm: | |
The misfire is more on hot engine,
thats why i thought on the warm up regulator.
But its not so much like it sounds.
I have a direct coil ignition, so there should be no problems on the cables and wires.
Where is the best place to measure the pressure ?
Behind the warmup regulator ?
Do You have some data for the FI pressures on these car ?
Thanks
Dirk |
Malcolm West (Ferrari_uk_tech)
New member
Username: Ferrari_uk_tech
Post Number: 44
Registered: 7-2003
| | Posted on Monday, August 18, 2003 - 10:42 am: | |
What car do you have, is the missfire there hot and cold ? It could be the metering head, however a fuel pressure test will cover most injection components including the warm up regulator. What condition are your wires / distributor caps in ?
MW
|
Dirk Rabenschwanz (Dirk)
Junior Member
Username: Dirk
Post Number: 53
Registered: 4-2001
| | Posted on Sunday, August 17, 2003 - 6:09 am: | |
My car has some problems in the transition range from idle to partial-load when i slow down and want to accelerate again. The injectors are new.
It sounds that there is a little misfire in this range. On idle, middle and full-load the car runs fine. What about the warm up regulator ?
I heard these part should rich the fuel mixture
just in this range.
Any ideas ?
Dirk |