Trouble brewing ...EA82T

steptoe · Post by **steptoe** » Sun May 16, 2010 11:07 pm

I am getting just a once in a few days momentary stumble outta my GLTM EA82T. First one occured in top up incline no boost, second was just cruising in top, both at about 80kph. Just enough to make me think , UH OH, stranded or KABOOM BACKFIRE, then stranded.

Being LPG fed there is not much control the ECU has over functioning, but there is the knock control module still relied upon. The good Eagle performance leads , Bosch cap and rotor have 50,000km on them, 3 NGK plugs have about 22,000 km and the other about 15,000 (lower compression and oils up) old donk of about 250,000 blows a little weed under hard acceleration and medium vacuum down mountains and the drive off after the descent blows much weed for a moment or two (better under BOOST) LPG more sensitive to poor sparks. Might be time to at least inspect the cap and rotor and replace plugs or at least #2 again or keep screw driver, torch and spare ignition module.

Not going to blame the LPG equipment, but maybe worth a look.
The last time I got something like this it was a corroded FL fusible link that caused great dramas - better check them too

Keep you informed

gtcompletepower · Post by **gtcompletepower** » Mon May 17, 2010 10:33 am

what size are your plug leads if you run gas you really need 9mm spiral wound stainless as they can short out under load

steptoe · Post by **steptoe** » Tue May 18, 2010 9:05 am

They are low ohm resistance leads made for gas in 8mm. Went to drive off in the cold yesterday morning and it did not feel right so just returned and swapped for the Brumby. Observed the gas converter mounted horizontally against best practice has gooey tar shtuff bubbling at a retaining screw. In this position such as used in EA, - ED Falcons the converter retains the junk oils and crap that can soften the diaphragms of the converter. Need to take a look and swap in a rebuillt ones after replace plugs etcas I have been meaning to do this preventative maintenance

T'subaru · Post by **T'subaru** » Tue May 18, 2010 9:59 am

hopefully an easy fix with a kit

spike · Post by **spike** » Tue May 18, 2010 10:46 am

gtcompletepower wrote:what size are your plug leads if you run gas you really need 9mm spiral wound stainless as they can short out under load

stainless plug leads??
they create massive resistance, id like to run (money persisting) aluminium cored well insulated wires

and another thing why are 3 leads new but the 4th old??

steptoe · Post by **steptoe** » Tue May 18, 2010 12:52 pm

Have fitted new NGK BP7ES gapped to 0.7mm for LPG one at a time, starting up each time and notice there is a little miss at light throttle stationary - could be low comp in #2 coming back to bite me - fitted up new cap and rotor, twenty bucks worth for 50,000km - deserves it. As for plugs, the factory manual has short plug life suggestion , was it every 20,000 or ten?

said 3x plugs, due to one pot having lower compression and a plug that gunked up more than others and suspected it caused a backfire sometime back up steep incline low revs, some boost, low speed in 5th. Did it before OK, but this day was hot and I may have pushed things too much. Replaced that one plug, back then

Also looked at LPG converter to find the oil build up internally (inline thermostat was designed /installed to prevent this) to be fair it should be anal ised to see if it is my engine oil or compresor oil and junk that comes in our ungraded LPG. It may be coming from intake via gas mixer balance line (time to make up a catch can)

Internally there are silicone diaphragms that are oil resistant that I just clean up, then there is the black hydrin material that goes all soft when in contact with mineral oil for too long (synthetic oil too?) Replaced that.

Also found some oil inside gas mixer houing and more importantly some scoring on an air valve slide due to being fitted on its side (not what it was designed for) it may be sticking - might have to polish this score mark out before replace and redesign intakes position. Mixer sits above rear PVC hole on mpfi block. looks like I can mount it the correct way uo directly above the turbo and make up new turbo to throttle body pipe - bypassing the factory alloy one fitted.

No time for inconvenience should a test drive prove it is still there. These gas converters also have a pressure valve on their intake on high pressure side. If that plays up it should keep running but go ultra rich.

plod, plod, plod

steptoe · Post by **steptoe** » Tue May 18, 2010 12:55 pm

Aaannndd..... I have to confess...the last oil top up before its next oil change (or engine out and good one back in) was 20W50 and not the 15W40 I have been using

upset a HVLA????

slinks away........

twilightprotege · Post by **twilightprotege** » Wed May 19, 2010 6:32 am

i'm guessing #2

my previous engine was doing something similar to that and #1 was really bad

but strange thing, i get a stumble at the moment with my HCEA82T (hehe). no idea why - compression is all good, engine uses no oil nor coolant - it's just odd. only happens around the transition between vacuum and boost, and only every now and then. tis easily overcome by giving it more throttle

steptoe · Post by **steptoe** » Wed May 19, 2010 9:11 am

well that does not sound like a weak valve spring that'd get worse as load and revs increase then appear when shift up to next gear and revs drop a bit - get a wobble sit and rest as it recovers and then good to go again.