Hi,

For a few days it got colder here - 10C (like 50 F) and my MR has big problems starting up.

When it starts in the morning, idle jumps 300-1500 RPM and sometimes even stalls. After about 1 minute when it warms up idle calms at 700 RPM and everything is fine. It also lights CEL "Cyl. 4 misfire" sometimes. I swaped spark plugs, but the problem remains. I also smell a lot of burnt gas in garage, like running incredibly rich.

When starting warmed up I have no problems.

Any suggestions?

Stock MR + TBE + AP modified stage2 map.

 

I'd say try swapping the coil from that cylinder with another one and see if the cylinder bank of the misfire changes. If that doesn't work, try the same with the injector.

 

Do you think the coil could behave like this (bad work when cold)?

I will take a look at the injectors, thanks for advise.

 

my old car did the same thing and i changed plugs wires and everything but the coil packs and it ended up being the coil

 

I changed plugs for new, MAF sensor for new, cleaned throttle plate and body, checked hoses for leak/unplug, but nothing went better.

First 2-3minutes in the morning the car seems like running only 2 cylinders with horribly fluctuating RPMs - (like 300 - 2000). Is there a way how to check (measure?) the coils?

 

I'm sure there is a resistance across the coil listed in the service manual. Did you swap the coils to see if the misfire shows on another cylinder?

You can also just unplug the coils one at a time while the car is cold. If nothing seems to change when one specific coil is unplugged then yits likely that that is the problematic one. You can then do a screwdriver test to see if it is providing spark.

 

I did not swap the coils, cause I am now getting either Random cylinder misfire, but usually I even do not get any CEL, which is something I really do not understand - how can a car run so ****ty without a CEL?.

I will try to unplug the coils one by one to see what happens.

 

Did you get this figured out by chance? It doesn't do this when its warmed up right? Or does it still have problems when warm?

 

ummmmm....
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The car probably isn't throwing a CEL because it is in open loop still or doesn't have enough "events" to trigger the CEL.

 

No problems whe warm - a little bit warmed is enough - only problems in the morning when temperature is below 50F.

I replaced spark plugs - OK
Checked coils - OK
De-mounted and cleaned the whole throttle-plate body and cleaned

I woder if Cranking enrichment table is used any way during warm-up as well or only during crankling????

 

does cobb modify the timing-trim-vs-coolant temp tables (forgot the exact name in ecuflash, but I'm sure cobb calls them something different anyways).

I have a similar problem... not so much during idle, but rather when driving between 1500-3000 RPM; the car loses power, RPM takes a nosedive, although no codes here. I think the timing "tweaks" these tables make are culpable, and may be worth looking into (i think there may even be a similar table for idle)

 

No, these tables are untouched. I have the same problems with stock map.

 

I think those problems are specifically related to our FIC 1100cc (or aftermarket injectors in general). It appears he has stock injectors.

So by "tested the coils" did you test the resistance, or test unplugging them?

Did you test the injectors yet? The same test for the coils could be done with the injectors. Test to see their resistance and test unplugging them 1 by 1 to see if there is any change.

 

I took the coils out, inserted spark plugs and all of them made regular sparks during cranking. (Could not measure the resistance as there is no default value mentioned in the service manual for EVO X)

Injectors are OK, I can choose whether to run gas on stock injectors or LPG on additional injectors (mounted in the intake manifild as well) and the cold engine problems appear on each of them. So that there is not a problem with fuel delivery, both system are independent (except for IPW, which is read from stock injectors).

I was thinking about problems with throttle plate, which couses too less airflow on idle while cold - could it be the way? (But I cleaned it and tried to measure resistance on the potentionmeter, but I could not find changing resistance on any couple of those 6 pins)

 

Is the LPG a digitally controlled injector? Also, I'd love to see some pictures of that setup if we could!

If there is an air leak (especially post manifold), its possible that the car cannot compensate for it while running in open loop during startup. This could cause some of your problems.