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OLDIE

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Feb 1, 2009
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I am tearing my hair out in fustration tring to find the cause of the miss that has developed recently NOTE the car has been running perfectly since a total rebuild spp 4k ago
AT idle and very light throttle there is a slight miss but as soon as you put the foot down it runs on 2 cylinders with an occasional pop from the exhaust
I has a Haltec E6X and 4 LS1 coils and waste spark and when the new plugs are checked no 3 & 4 are blackish BUT are dry suggesting that there is some spark otherwise they would be wet so I have done the following
1 changed plugs
2 put timing light on all leads while idleing all are flashing
3 Had RACQ check injectors with stescope and all are ticking He suggested that it was the leads or the coil failing NOTE they are 800cc Sards that were cleaned and tested before they went into the new motor
4 Replaced coil
5 I pulled coil and inj leads off had a wriggle and put them back and it ran on all 4 so went for a drive and after app 200 metres back missing again
5a went to local sparkie who just took coil and inj leads off had a bit of a look put them back ant it ran on all 4 home BUT when started next day it's missing again
6 my builder / tuner replaced the pins on the inj and coil lead ends still missing
7 take leads to ULTRA TUNE resistance test they test ok
8 drive to Ultra Tune and 4 tecs around car and they hear something shorting out and find no 4 lead shotring out in the tube that connects to the plug so they fit an old lead and miss gone!!! so drive 6k home on all 4 or 3 and a half
9 Start car nxt day WTF**#** IT'S MISSING AGAIN
10 Had Qld Ign Leads who made the custom 9mm leads for the new motor check 3&4 leads and found no 3 was not connecting to the plug propperly so he fixed that and fitted a new tube to no 4 STILL MISSING so I wrapped insulation tape around no3 & 4 tubes still missing
GETTING DESPERATE NOW
New EAGLE leads on order NOTE they are custon length and a custom connection fit to the LS1 coils so can't just get them over the counter
NEW ignition switch on way fron Japan
If they don't fix the problem then the injectors will be pulled and tested again and the haltec sent away to be checked
I have also pulled battery & motor earth straps off sanded the contact patches and refitted them along with a new altenator
NOTE THE HALTEC WAS REWIRED WHEN THE MOTOR WAS BUILT

ANYONE OUT THERE WITH BRIGHT IDEAS OR HAVE I MISSED ANYTHING
 
Is the Haltech showing any error codes at all?
Have you swapped injectors to other cylinders to see if it follows the injectors?
No broken wiring going to your coils perhaps if its running on 3/2 cylinders? Also, the coils, i can not recall what LS1 coils look like, is it 2 coils in a pair or each individual coil like bosch items? wondering if its the two coils running cylinders 3/4 that have issues, swap coils over to 1/2 when it has the issue.
Check your haltech, see if its throwing any errors, its a good place to start. and how bad is the miss. Is it just a pop from time to time, or are we talking that it is literally only running on 2/3 cylinders?
 
iluszn said:
Is the Haltech showing any error codes at all?
Have you swapped injectors to other cylinders to see if it follows the injectors?
No broken wiring going to your coils perhaps if its running on 3/2 cylinders? Also, the coils, i can not recall what LS1 coils look like, is it 2 coils in a pair or each individual coil like bosch items? wondering if its the two coils running cylinders 3/4 that have issues, swap coils over to 1/2 when it has the issue.
Check your haltech, see if its throwing any errors, its a good place to start. and how bad is the miss. Is it just a pop from time to time, or are we talking that it is literally only running on 2/3 cylinders?
Click to expand...
REALY BAD BAD MISS
ONE COIL PER CYLINDER same as a 5.7 litre commodore v8 NO 1&4 spark plugs fire at the same time = waste spark
 
Yeah you've got the same 4 x LS1 coils with built in ignitors like mine but Im running a Haltech E8 ECU. Sounds more like a tuning issue and best diagnosed on the road or dyno with the laptop plugged in. Has your Haltech tuner gone over all the settings in the ECU again to make sure he didnt miss something? The 4 x coils with built in ignitors is relatively an easy conversion with something like the Haltech so I'd be double checking the ECU's ignition settings, especially if he has set the dwell too low which would definitely cause missfires.
 
EVO-00X said:
Yeah you've got the same 4 x LS1 coils with built in ignitors like mine but Im running a Haltech E8 ECU. Sounds more like a tuning issue and best diagnosed on the road or dyno with the laptop plugged in. Has your Haltech tuner gone over all the settings in the ECU again to make sure he didnt miss something? The 4 x coils with built in ignitors is relatively an easy conversion with something like the Haltech so I'd be double checking the ECU's ignition settings, especially if he has set the dwell too low which would definitely cause missfires.
Click to expand...
The strange thing is that it has been running perfectly for app 4000k's so why would the settings cause problems now ???????
 
Check your wiring, I would also look for a crushed wire shorting somewhere? Loose connection.. If its idling and has a severe miss, start playing with the loom.
 
Id also be swapping out the Cam angle sensor for a known good one and then redo the timing once the replacment is in.
You didnt mention whether the CAS was replaced or checked as its also an integral part of the ignition system worth investigating.
 
I had something similer on my haltech E6K,with my mgb with the vr4 1g motor would sometimes get a bad idle and under acceleration it would run like a hairy goat.i would plug my laptop in and check the program tune parameters with my backup program which was all fine,including setup of the ignition trigger because i had that problem of dwell when i first setup the program even my coil charge time of 3.5 would be fine.but i would end up reloading my program back in to the haltech and it would be be back to normal running for maybe another year.its like the program corrupts it self in the haltech memory.I know this sounds strange and might not be what happening to you but my e6k does it about once a year.and i know the parameters on the mg since i did the tune program myself,so when i said earlier that i check it ,i know what to check. but my setup is factory coils and injectors wired into batch fire mode
 
chuck out your battry. get a new one and fit a voltage stabiliser to it.
most after market ecu's are temprmentle and need a stable current.

the battery is the most overlooked part , yet the simplest and often cheapest to change.
 
no:fuuuuu::fuuuuu: comp test hot or cold all within 5psi .have new no 4 coil ,leads,plugs ,tested coil harness 16 pins all ok , changed to a set of VR4 coils no change, am going to spray all connections with contact cleaner to see if that helps but not holding my breath on that and am about to get injectors retested. Will let you know if and when we find the #%*+#** cause as it's p*#**%g me right off big time:fuuuuu:
 
bazeng said:
How is your Crank Angle sensor wiring?
Are you getting noise?

Are the contacts ok?
Click to expand...
Pulling all contacts apart today and giving them a good dose of contact cleaner so will see if that helps at all:unsure:
NOISE what NOISE I an as deaf as a post only have app 40% hearing
 
After much anguish and banging head on brick wall would you believe it was not an ignition fault but a fuel flow fault .Bloody Sards Originally it was no 3&4 cyls missing then it changed to 1&4 and so naturally thought as it was on waste spark it was an ignition fault so after checking every wire for the umpteenth time with a multimeter and all the ign & fuel maps Lee reduced the fuel to 1&4 and it ran on all cyls so it appears that the injectors are faulty and staying open too long and excess fuel was causeing the plugs to missfire.So now I will get some Siemans 780's and hopefully thats the end of problems for some time
 
780 cc Siemans now in place and it's great to hear it on all 4 now BUTstill need to do a road tune with the lap top & sniffer up the exhaust to be sure of the fuel maps with the new injectors then it's Leyburn Historic Sprints hereI come PROVIDED I am invited:unsure::)
 
Great to hear :)
Hey Oldie, is your name Greg?
My Mrs found an Australia Post satchel in the boot of her car dated back to 2007 with an alternator bracket in it? I can vaguely remember telling her to mail it to an address in NSW but it looks like the ^%$& forgot??? Was that you??? I see you're in QLD though?
 

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