• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

strange intermittant missing

A

Antiferret

NAXJA Forum User
Location
Redbank Plains
OK

misfires after first 10 seconds from startup at all rpm's IN PARK AND NEUTRAL (no load?).

if i left foot brake and put in any drive gear and rev it higher than PRECISELY 1250RPM, RUNS SMOOTH AS SILK.

both conditions above when cold and warmed up.

since replaced:
injectors
cap/rotor
leads
plugs
coil

IAC clean, checked sensor voltages for MAP, TPS, CPS, Cam PS.
no vac leaks either.

any clue where to check next? this is turning me to heavy drinking to cope:shiver:
 
OK Done, there is no 12v+ being supplied to the heater, only about 1-2 volts. where does this come from and is there a known issue.

heater resistance is 6ohm BTW.
 
There is a relay on the passenger side inner fender. Mine died when the wires got caught up in the front drive shaft, and then landed on the exhaust manifold and fried...... Sounds like you may just need to clean contacts on the relay, male and female, and or replace the relay. It is the fourth relay closest to the battery.

What year is yours?
 
Last edited:
Ecomike said:
There is a relay on the passenger side inner fender. Mine died when the wires got caught up in the front drive shaft, and then landed on the exhaust manifold and fried...... Sounds like you may just need to clean contacts on the relay, male and female, and or replace the relay. It is the fourth relay closest to the battery.

What year is yours?
Click to expand...

1996 - changeover year, to make matters worse being an Australian car your passenger side is my drivers side! apparently here it is controlled by a "ASD" relay (PDC is different to yours) and also supplies to the other o2 sensor. I test swapped with another relay with no change. is there a fuse? i would have thought if there was a shorted wire that the fuse would blow instead of reading low voltage?

worse case scenario i can hard wire another relay to supply 12v but need to know what current fuse to use.

ground is good however.
 
how much side to side play is allowed for the distributor rotor/cam sensor shaft?

mine seems to move about 3-6mm (sorry, don't know fractions of inches) and distributor seems to knock (tap) occaisonally.
 
There is a fuse link coming off the small starter relay near the battery. It has a 1/4" post with a large red wire from the battery to it and several more wires leaving the post to most large loads like the O2 sensor heater relay. One of them is the one you want, they all have OEM fuse links in the wires.

But all mine are Renix Era, 85-90 years, so yours may be different.
 
Antiferret said:
how much side to side play is allowed for the distributor rotor/cam sensor shaft?

mine seems to move about 3-6mm (sorry, don't know fractions of inches) and distributor seems to knock (tap) occaisonally.
Click to expand...

They have a fair amount of slop in them, 3 mm sounds OK, 6 MM may be pushing it, but that depends on where you measure!!!! At the end of the rotor, 6 mm may be OK, but is pushing it!
 
Antiferret said:
how much side to side play is allowed for the distributor rotor/cam sensor shaft?

mine seems to move about 3-6mm (sorry, don't know fractions of inches) and distributor seems to knock (tap) occaisonally.
Click to expand...

Bingo,,,, you have found the problem.It should have thrown a code and CEL should be on. Don,t run it long or you will burn up the cat...
 
Wayne Sihler said:
Bingo,,,, you have found the problem.It should have thrown a code and CEL should be on. Don,t run it long or you will burn up the cat...
Click to expand...

Really? rotor doesn't seem to hit and cps signal is sweet.

if this is the prob, do i need to replace the whole unit? is there something i can rig up to run the engine for 5 minutes so i can confirm/eliminate?

maybe the engine oil flush eliminated some crud, increasing play (did it at the initial service)
 
If you are hearing and feeling a knock in the cap then the rotor must be hitting one of the terminals .Look at your old cap/rotor see any signs of interference ?

Replaced dist in my 96 at 165,000 in wife,s 98 at about same mileage . I doubt that anything you did to the oil caused the wear problem to suddenly show up.
You will need to get the O2 sensor problem fixed to be able to run the engine,
 
ok, replaced distributor housing as there is too much play anyway. problem not fixed.

before i replace both O2's, i want to know if the Neutral safety switch can do this?

i keep coming back to how the car runs sweet in gear under load at precisely 1250 rpm and above.

cheers for the suggestions so far.
 
So what happened to fixing the real problem, namely getting 12 volts back to the O2 sensor heater? At idle, the O2 sensor gets too cold and quits giving the computer correct data, causing the miss.
 
apologies, have still been on the case.

there IS 12+v getting there, Australian delivered sensors have funny coloured wiring compared to yours, so i was checking the wrong wire:gonnablow
both grounds good and resistance tests fine.

stay tuned, i will next test the SIGNAL wire (the one i thought was the dud 12v) while the engine is on.

everything is pointing to a 02 sensor, it has to be, replaced nearly everything else!
 
You must log in or register to reply here.

Similar threads

C
91 XJ missing at 2000 +rpm only when at operating temp
Replies
0
Views
1K
cptmiker
C
A
Long crank when engine warm
Replies
15
Views
3K
aquaman788
A
B
Jeeper needs Help !!
2
Replies
22
Views
3K
denverd1
denverd1
A
Very odd idling issues
2
Replies
38
Views
4K
Rob Mayercik
R
E
Odd engine problems
Replies
11
Views
636
Ekacpuc
E
Back
Top