Have a missfire ??? Check your ECU multiplug terminals...
Discussion
Well I'm pleased to say that so far (hope I'm not tempting fate) my miss fire seems to be cured.
As I thought, the gap between the pin terminals in the ecu multiplug housing were far too wide and thus they were not gripping the ecu terminals properly causing a random missfire.
So I bought a new multiplug, spliced the old one off and rewired the new one on.
Only slight hiccup was getting terminal 26 mixed up with 28 (I need new glasses) but once corrected it runs lovely.
What I have noticed is that it idles really smoothly now as well as running smoothly throughout the whole rev range.
So I have to thank smash as some time ago he told me that he had a conversation with an expert and a lot of missfires are attributed to either the multiplug or a wiring fault in the loom in some shape or form and not necessarily the ecu itself.
Fingers crossed.............
As I thought, the gap between the pin terminals in the ecu multiplug housing were far too wide and thus they were not gripping the ecu terminals properly causing a random missfire.
So I bought a new multiplug, spliced the old one off and rewired the new one on.
Only slight hiccup was getting terminal 26 mixed up with 28 (I need new glasses) but once corrected it runs lovely.
What I have noticed is that it idles really smoothly now as well as running smoothly throughout the whole rev range.
So I have to thank smash as some time ago he told me that he had a conversation with an expert and a lot of missfires are attributed to either the multiplug or a wiring fault in the loom in some shape or form and not necessarily the ecu itself.
Fingers crossed.............
I've got a random misfire which started on the way back from Millbrook on Sunday. I did thrash it somewhat. I've checked plugs (spot on), checked for obvious wiring faults, checked connections on the power resistor, ignition amp etc and all seemed well. I've ordered a new coil for starters just to rule that out but I'll extract the ECU to see what condition the terminals tonight also.
One question but the ignition amp is not tight on the distributor. Does it use the distributor body as the earth? Also no evidence of any heat dissipating paste. Do others have this?
One question but the ignition amp is not tight on the distributor. Does it use the distributor body as the earth? Also no evidence of any heat dissipating paste. Do others have this?
Do i need to repeat myself again.....
I have said it more than once on here to check all your connections...I go through mine every month..AFM..Ballast resistor..ECU plug...Thermotime...CTS...I also wipe the dizzy cap out..I wipe the rotor arm now instead of trying to keep it ultra clean with a piece of 1200grt wet'n'dry which actually caused the film to come off the metal and caused erratic spark distribution..
I do not touch the injector plugs or TPS as i don't wish to disturb them...Unless they are the problem.
Most of the components..Including the loom are getting on for 30 years old now so most of the time its a simple fix, Albeit a bugger to diagnose...Unfortunately when people start changing every part on the car randomly it can all become very cloudy as to what you replaced..Put back...Did do..Didn't do..
With mine one of the previous owners was relieved of 13.5K over a 6 year period by Tower view racing trying to diagnose an intermittent mis-fire, There is even a bill for 2.5K for engine work which hopefully was the cam.
It had 8 injectors rebuilt..A new 9th injector...ECU rebuild...New thermotime & CTS...Part loom replaced...Plugs...Leads..Coils..Rotor arm..Ignition amp..Then i come along and find twisted CTS wires...Result.
Glad you got it sorted now ... Just drive it...And enjoy it....Ziga
I have said it more than once on here to check all your connections...I go through mine every month..AFM..Ballast resistor..ECU plug...Thermotime...CTS...I also wipe the dizzy cap out..I wipe the rotor arm now instead of trying to keep it ultra clean with a piece of 1200grt wet'n'dry which actually caused the film to come off the metal and caused erratic spark distribution..
I do not touch the injector plugs or TPS as i don't wish to disturb them...Unless they are the problem.
Most of the components..Including the loom are getting on for 30 years old now so most of the time its a simple fix, Albeit a bugger to diagnose...Unfortunately when people start changing every part on the car randomly it can all become very cloudy as to what you replaced..Put back...Did do..Didn't do..
With mine one of the previous owners was relieved of 13.5K over a 6 year period by Tower view racing trying to diagnose an intermittent mis-fire, There is even a bill for 2.5K for engine work which hopefully was the cam.
It had 8 injectors rebuilt..A new 9th injector...ECU rebuild...New thermotime & CTS...Part loom replaced...Plugs...Leads..Coils..Rotor arm..Ignition amp..Then i come along and find twisted CTS wires...Result.
Glad you got it sorted now ... Just drive it...And enjoy it....Ziga
KKson said:
One question but the ignition amp is not tight on the distributor. Does it use the distributor body as the earth? Also no evidence of any heat dissipating paste. Do others have this?
It's yes and yes. The amp body should be held on tight to the distributor body with two screws, one on each opposite corner. I believe it does earth through them. Also there should be a paste thinly applied to the rear of the ignition amp usually supplied with the amp itself. I'm not sure if it's for heat purposes though, it may be more for earthing. I have replaced this on mine with a good quality item and it has made a big difference to the starting and running. Only, beware of cheap imitations, unless you like changing it regularly.Tony. TCB.
KKson said:
I've got a random misfire which started on the way back from Millbrook on Sunday. I did thrash it somewhat. I've checked plugs (spot on), checked for obvious wiring faults, checked connections on the power resistor, ignition amp etc and all seemed well. I've ordered a new coil for starters just to rule that out but I'll extract the ECU to see what condition the terminals tonight also.
One question but the ignition amp is not tight on the distributor. Does it use the distributor body as the earth? Also no evidence of any heat dissipating paste. Do others have this?
Hi Keith...As said the amp should be secured firmly..I think its held in place by two screws..You should see some remnants of paste if its been changed at any time..I can see it on mine and i know it was changed about 8 years ago.One question but the ignition amp is not tight on the distributor. Does it use the distributor body as the earth? Also no evidence of any heat dissipating paste. Do others have this?
Might be worth changing to see if its the culprit.
Ziga
Hi Keith...Be careful when cleaning the ECU pins...You don't want to score them up too much...I used a really fine emery board and some electrolube contact cleaner..I find an old tooth brush comes in handy as well...Or a cheap new one.
I give them a little light rub and then clean with the lube and tooth brush, Wait a few minutes for the cleaner to disperse before connecting the female plug..From then on its a regular thing ..Dependant on usage ..but just with the tooth brush....
For the female receptacles i just use a lubed up tooth brush...(Said the bishop to the actress)...
I give them a little light rub and then clean with the lube and tooth brush, Wait a few minutes for the cleaner to disperse before connecting the female plug..From then on its a regular thing ..Dependant on usage ..but just with the tooth brush....
For the female receptacles i just use a lubed up tooth brush...(Said the bishop to the actress)...
mrzigazaga said:
bluezeeland said:
mrzigazaga said:
For the female receptacles i just use a lubed up tooth brush...(Said the bishop to the actress)...
I see....
Hope you enjoyed the 50th mate...Shame i could not make it...
maston said:
So I have to thank smash as some time ago he told me that he had a conversation with an expert and a lot of missfires are attributed to either the multiplug or a wiring fault in the loom in some shape or form and not necessarily the ecu itself.
Fingers crossed.............
That would be John Eales Fingers crossed.............
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