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Resolved new motor stage 3 misfire cyl 1 HELP

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442powerstroke

Proven Member
168
6
Jun 6, 2013
sacramento, California
im in need of help please any 1 please help heres my symptoms

it seams to run great till is gets warm then starts to sound like a piece of $hit subaru.
mis fire ? is my guess been working three days stright on it i put new motor in it and now i have this prob.

motor is fully built by me ross pistons manley rods iggly griddel acl race bearings ported head bc titanium evo 8 rockers bc 280 cams aem cam gears, gtx 30r turbo trial wastegate greedy bov dsm v3 gm maf with ecmlink direct cable .going to sd ASAP

with that said i already had everything up in going with old stock motor only thing that is new to set up or underhood is bc 280 cams and knock sensor

what i have tested/ swaped parts since problem

new ngk plugs gaped.028-30 made sure timming right on tbelt two times made sure ignition timing is 5 tdc,did comp test 170+ on all cyl made sure CAS is right not 180 off swap inject risster, killed injectors in dsmlink one by one seams like #1 no diff on or off when i pull plugs cyc1 its spraks when pulled but no drop in engine performance , vac psi good at over 10-15 psi at idle. swamped injector from cyc1 to cyl2 cly1 still no diff when cut.

this seams like a electric problem when its cold it seams to run purfect WTF im stumped anything to look for in dsmlink?
im leaning to bad ecu?
i have also read bad lifters? i have new topline 3g lifters

i can up load a log on v3 too
 

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first off just because 1 and four fire at the same time its still coil on plug, this just means that the 2 coils get a signal to spark at the same time but still 2 separate coils. I suspect the #1 coil is going bad! change out the coil and your troubles should go away.
 
first off just because 1 and four fire at the same time its still coil on plug, this just means that the 2 coils get a signal to spark at the same time but still 2 separate coils. I suspect the #1 coil is going bad! change out the coil and your troubles should go away.
It does. Same thing with cop set up as stated in earlier comments
 
You didn't mention where your running good or bad in your logs.
 
Not personally but I have repaired plenty of engines that have and your symptoms are the same. Did you have new guides installed in the head?
 
The o2 sensor voltage doesn't move at all on the newer log from 0. Either a dead o2 sensor, severe lack of fuel, or a bent/sticking valve just pumping air through the engine. Try another o2 sensor, check fuel pressure, or perform a leak down test on #1.
 
The o2 sensor voltage doesn't move at all on the newer log from 0. Either a dead o2 sensor, severe lack of fuel, or a bent/sticking valve just pumping air through the engine. Try another o2 sensor, check fuel pressure, or perform a leak down test on #1.
did leak down test today on all cyl and all were great less then 10 Leakage when i looked at o2 it was reading i will try to lock it into open loop and see if it changes. i cant belive no one has ever had this problem runs great untill worm up then miss on cly 1 im ready to rip this motor out of bay and totaly go therw everything whis is driving me nuts
 
I would say there is a good chance that you have one or more guides that were'nt properly sized after installation.
 
but why does it run great when coldish and when its hot it seams to run good for for min then go into limp mode

I need you to add Fuel Trims to your log (STFT and all LTFT) as well as ISCPosition, TPSDelta and MAFRaw. Then get a new "good" log and "bad" log and name them so we know which is which.

Also, do you have a wideband? If so, get it wired in and logging ASAP. It would really help to see it in the logs.
 
Do you have a fuel pressure gauge installed? If so how long does your fuel pressure stays up after you turn the car off? In other words how long does it takes to drop to Zero, is it gradual or is it almost immediate?
 
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so heres a video on progress on problem i have narrowed this down to cyl no 1 and its the spark it seems do be inconsistent flash compared to other cylinders . im thinking my ALT is the prob my battery is going low when running its starts at 12.3 then after running drops to 11.7 or less then cant start car i think this is the root of my missfire problems when my old motor was in my HKS turbo timer read 13,2 when runing now below 11v ? the coils are 12v so?
 
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so heres a video on progress on problem i have narrowed this down to cyl no 1 and its the spark it seems do be inconsistent flash compared to other cylinders . im thinking my ALT is the prob my battery is going low when running its starts at 12.3 then after running drops to 11.7 or less then cant start car i think this is the root of my missfire problems when my old motor was in my HKS turbo timer read 13,2 when runing now below 11v ? the coils are 12v so?
It could very well be the issue for sure!
 
Yep, sounds like a bad alternator. You should be seeing 13.5-14.8 volts at the battery with the engine running. Anything less and the charging system isn't doing its thing. If you have 12.x volts that ain't gonna cut it. :nono:
 
Make sure it's oem mitsubisbi or you will continue to hve alt issues.
So put other old know working alt in now volts when running is 14.2 it fix volt prob but runs like crap when gets warm and still cyl 1l. The flash looks better on timming light but still dead cyl so its a lifter or stuck valve guild im pulling off head tonight when i get home any input i would appreciate it?
 
Have you done a compression test I've done a leak down and passed but failed compression test and have you checked the little capacitor that's bolted to the intake manifold. Maybe it's insufficient power to all 4 coils so 1 gets the weakest amount of amps.
 
You think you can see anything with valve cover off before pulling the head?

Do you need to degree the 280's?
I have moved cam gears a bit both ways and i get less compression when i do it so i know i got them in a good spot degree would be best but i was going to dyno tune and get cams spot on. Again it seams to run strong couple mins then starts to miss
 
So put other old know working alt in now volts when running is 14.2 it fix volt prob but runs like crap when gets warm and still cyl 1l. The flash looks better on timming light but still dead cyl so its a lifter or stuck valve guild im pulling off head tonight when i get home any input i would appreciate it?

I wouldn't pull the head yet. I don't think a stuck lifter would be temperature dependent. A guide could be affected by thermal expansion but i wouldn't think it would be enough to kill the cylinder. Get another log with the values I asked for and post it.

Have the car off and cold. Turn the key on and connect with DSMLink. Start a log. Start the car. Allow the log to run until the behavior happens. Note the exact time in the log. Allow to run for another minute or 2. Stop the log. Post the log and the time noted earlier. Win :coy:
 
Have you done a compression test I've done a leak down and passed but failed compression test and have you checked the little capacitor that's bolted to the intake manifold. Maybe it's insufficient power to all 4 coils so 1 gets the weakest amount of amps.
150 comp on all cyl changed power transistor out with two other runnig dsms i had power trans prob b4 its kidda like the problem but nope not this time
 
Besides the valves, did you get the proper line hone and machine work for your griddle? Dunno if it could be related but it definately sounds like heat is an isssue, and when metal heats it expands, maybe it could be a valve guide closing in on a valve? I'm not sure but if it only happens when it's hot I'd look at things that could bind when hot if something could potentially be out of spec
 
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