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Swapped DFI/Coil Pack, car only starts when wiggling plug leads, Replace plugs leads?

HyperThinker

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Hey guys, ive been reading threads on here for some time and used it to diagnose and replace a faulty DFI / coil pack. The new pack tests 5k ohm.

*** A big thankyou for all the FAQ threads and stuff because its saved me $100's of dollars so far!! ***

Since then my car hasnt backfired once,. however i have isolated (through trying 100 different things) That the car will only start when the plug leads are wiggled in a certain way, Ive wd40'd the **** out of them and done everything else ultra carefully so if they've been damaged i could of been through a time i had a radiator blockage and my engine ran hot as hell for 1 hour.

They are all testing 2-3.5 at 20k ohm (spiral wire) however the logical thing here seems to be to replace the plug leads?

Thanks in advance for any answers, I've spent two weeks trying to fix this before i asked :D.

Oh, when the car is HOT things run absolutely peachy smooth as silk, however when it is in the heating up phase it stalls.

This would seem to indicate the dodgy connection is expanding and closing securely. Because for 6 hours after its been run it will start without the slightest hesitation.

It also runs on LPG only as my fuel pump has died. However until this problem it had no issues with that. Its actually a 10,000km old engine as it was fully rebuilt when it seized.

Cheers.
 

Brett_jjj

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Definitely get new leads,and get new plugs too while your at it.And seeing its on gas, you should have the spark plug gap set to 1mm instead of the normal 1.5mm.
 

HyperThinker

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Thanks mate, im a bit scared of going near the spark plugs myself but ive ordered some top gun gas spiral leads.

From what ive read, it shouldnt run like a brand new car when its hot if its spark plugs are bodge? However it does, it runs brand new once its hot.

Thanks for reply.
 

HyperThinker

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Well i just got the last mechanics receipt and the plug cables are 5k old, which is ridiculous for them to fail right! (their gas spiral leads) , that and the fact they pass my multimeter test make me really think its the spark plugs and all my random cable wiggling hasnt done a thing. Lol.

:\ gunna order the plugs tomorrow.
 

db_notso

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its not possible to run solely on lpg in australia as far as i am aware (as i tried recently)
as the emissions laws prevent warm up on lpg...

plugs would also be badly affected on solely lpg warm up
from my former wasted research i would have to run iridium twin electrode plugs to counter this
last check there 170 bucks a set from repco...

put some petrol in the tank and try it
 

FXST01

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I think you'll find it runs crap when starting to drive is because the coolant that heats your gas regulator is still cold and possibly the regulator is freezing.

I'll will hazard a guess and say that it takes a while to start?

As for re-gapping your plugs, well I personally would leave them at 1.5.
 

HyperThinker

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bosch platinum plugs in.

Firstly thanks for all of you helping out this car illiterate computer nerd

FXST01> Does the gas system use its own coolant? or borrow from the cars? Could it be possible this is blocked?

The petrol system is stuffed, the mechanic rigged it so i could temp drive only gas i think its the oxygen sensor and or the fuel pump, i cant remember whatever it is it allows me to drive with gas switched on and was running beautifully for 6 months.

Needing expensive plugs doesnt make sense as the ones i took out were shitty generics.

(gotta check bill but I'm sure they wrote me up for bosch :| )

So i changed the plugs,. the old ones were absolutely covered in dry black sooty grimey stuff.

According to the interweb this would explain all my hard starting ect; as it is carbon deposits from an inappropriate fuel/air mixture.

Since putting the new ones in , i can only get 2 minutes of attempted starts and now it REALLY sounds like there is ignition as i can hear soft whoomp or expanding air sorta noises and the ignition sound is irregular whereas before it was a perfectly uniform grating sound as the car tryed to start..

Its charging now, and ive just put in my old DFI module which looked absolutely perfectly fine when i took it out (and was replaced with a shitty one that came attached to coil packs)


Id read about the problem with gas vaporization and id previously poured hot water over the ring mixer for about 30 minutes before trying to start with no success, do you think i should do this again now? (its not the greatest thing for the nearby electricals obviously)

Before this ignition problem it would start on gas INSTANTLY every time, weather it was 3am in the bush or a hot sunny day. The engine was fully rebuilt specifically for LPG whatever that means.

So in summary

1) I swapped plugs + leads + coil pack + dfi. I heard expansive air sounds like some cylinders were igniting, im suspecting maybe i need to run the battery down a few more times while i attempt ignition to clear out the **** from 3 weeks of failed ignition attempts?

2 I put in the DFI i had taken out, which had absolutely not a blemish on it and looked like it was replaced 1 year ago when entire engine was recoed.
It made the same sounds, irregular lumpy ignition compared to the old spark plugs when it made a droning regular unchanging grating sound when trying to start.
I also unclipped the airbox for this attempt as it sounded like it was choking a bit (good bad?)


3 Tomorrow i try old coil packs, which tested fine ( 3k ohm higher then the new ones )

Anyone have any advice before i get the f*cking thing towed?
 

HyperThinker

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SHE STARTED!!!!

And here is the interesting thing, i seem to of had success using this method when the electricals were bodge.

I left the ACC on for 10 minutes before attempting ignition, thinking if theirs power in the gas mixer thing it must be happier to be ignited if its been prepared for 10 minutes.

It almost started, then i turned off for 10 seconds, back on counted 10 and ignited and its fine.

Now the car idle is completely smooth, not lumpy their is no stalling

Seems to be fixed, logic tells me drive it straight too the gas tuner and of course its a Saturday. >.<
 
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