Hi,

I have done a rebuild by Oppliger Motorsport, 582hp @ 1.75bar of boost with E85 fuel (105ron). No problem there as its a beast.

The car performs very good once it is hot and running, but now when temperatures drop below 10-15degrees outside it doesn't want to start at all.

Plugs are IK31.

Romain Oppliger came from Italy to Belgium to fix coldstart problems and it was OK untill now its 5degrees and i tried to start it after 1 week and it doesn't want to go again.

Keeps cranking and you hear it WANTS ignition but after 10x i stopped..
The problem could be the plugs as they are "cold", but i want a 500+ engine that i can drive ANY DAY of the year and not only when its 20degrees outside.
I also tried cranking with the injector plugs removed because it maybe overfueled or somekind.. But no succes.

Anybody got another idea?
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Cold start map needs more work

 

That would be my first thought, providing the coolant temp sensor is good.

 

Cold start map is no good.
If you want i can have a look at the maps.

 

too little fuel during startup.
plenty of topics regarding e85 and cold starts

 

What management is the car on? Reason I ask is your mapper might be able top tweak it remotely via email?

 

Hello,

I'm now on the 98ron map, i have 2 fuel maps, and i drove the tank all empty on Ethanol and filled with 98ron (here in Belgium). So right now the car doesn't start on normal 98 fuel with these Denso IK31... my ignition setup is:

EMU aftermarket ECU with coil on plug (i think from yamaha bike). So normal plugs like 071 don't work i guess?

What about if i go IK27?

Cheers for the help so far!!

 

You need to adjust cold start enrichment in the ecu. Do you have a wideband lambda to check air fuel?

 

Yes i do, but since the car doesn't start i don't have readings about that? It's an Innovate one and it needs time to "heat"... :-/

BTW, je kan mij ook toevoegen op facebook of via pm sturen in't nederlands Bart

 

Je hebt een PM

 

The IK27 plugs are more for track day use when the engine is running hotter, I dont think they will help but if you have a set try them.

 

IK 27 is the correct heat range for a 500hp engine.

Mark

 

Sounds like it was running ok on the Ik31s but as I said if hes got the IK27s put them in and try it.

 

31 is to cold for 500hp it can be done but there is no need for such a cold plug.

Mark

 

Mark,

Thank you very much for your input.

Right now the engine makes between 550 and 580hp..

So IK27 still OK for that heat-range?

Cheers!!

 

I use the IK27 from 400 to over 700hp but its best to ask your tuner.

Mark

 

Oppliger uses all the time IK31, but i don't think it will hurt going IK27..

Anyway, i'm going to get me some cheap supermarket plugs to get it started and then switch to IK27 or 31's again...

In Belgium we have about 5° temps now and i guess since the cold-start map is not good enough i can only switch plugs no...?

 

The colder the plug the narrower the window of getting the cold start right and the cold start map should only be a offset of warm running,
But it can also be down to how much adjustment the ecu will allow,
Try hot stock plugs to see how it sets but do not drive it hard.

Mark

 

By the way,

I see IK27 is a lot cheaper then IK31?

I've read somewhere, i think it was Stu from MSD, that Irridium plugs don't ever need to be regapped. Right now i've gapped mine to 0.4mm, factory gap is 0.6-0.7 i think.

Any advice?

 

If you are running .4mm your spark system is not good enough and also cold starting with such a small gap will suffer.
Gapping is fine I regap them all the time.

Mark

 

CHeers for the info.

I've just read it today in topics about gapping and plugs.. Stu or James @ MSD said it was not done gapping the irridium's (IK27-IK31)

Since engine rebuild it's 0.4mm gap yes. Spark system is coil on plug wasted spark ofcourse.

See in pic the coils:

 

Does anybody know if the Ford plugs AGPS071C have a removable tip, so i can use them on my coil on plug coils? It's only for making a startup, for hard use and boosting i will use IK27 then!

Cheers!!

 

i think they have Melvin.

 

Lets hope. Gonna order me 14 sets LOL

 

Some people even use the 71C for 550+ engines... is that a good idea? I think at 2.2bar the spark will be blown out on these maybe..

 

I dont like them to much. Last set i used on a stage 3 car blew the spark at 1,3 bar. This was with new leads, rotor, cap and grA coil.

 

That's crazy

 

I use the standard ford plus on 2.5bar no problem!

 

Hi Pieterjan,

I know your name from Ward

Standard plugs, AGPS 071c motorcrafts?

 

Seems like the new 071 have many bad plugs.
I would use ik27 like i told you yesterday.

 

I ordered the IK27, should have them tomorrow.

Hope the car starts instantly with 0.6 gapping and then see what happends on boost.

I still find it strange to go from 0.4 to 0.6 or more

 

Yes standard ford plugs. Always used them and never had any problems whit my cossies.

 

Nice. What spec you're running now?

Sierra or Escort?

I'm waiting for IK27 now and also Oppliger sends me a set of ford plugs

 

James (Or I?) will have meant that you have to be extremely carefull when gapping the Denso iridiums as the 0.4mm centre electrode is quite brittle and can be bent and even snapped. We gapn them all the time but for your setup out of the box at 0.7mm should be fine and no less. certainly NEVER less than 0.6mm on any cossie. Any lower than that needed and you have other problems.

Also, do NOT overtighten them. This is what causes the centre insulator to crack. Overtightening them stretches the casing (as does any bolt) and this can be an issue. Just factory specified tightness and no copper grease or other stuff some folk like to fit.

For the record, I would use IK27s on yours.

 

Alright! Great advice here.

Cheers all! Still waiting on the plugs, last time i ordered where IK31 from MSD, almost next day in Belgium.. now waiting 3 days from another supplier

 

I still find it very crazy that Oppliger supplies me IK31 and gap it to 0.4mm...

I used 3 sets now, all dead.

So when i got the car back after rebuild, the plugs where 0.4mm gapped, its so low, so you think there's something wrong?

Also running the wasted spark and coil on plug so i don't know what or why...

 

Just try them at 0.7mm
Normally this wouldnt be a problem.

 

I guess so, but then its still a mistery why Oppliger says 0.4.
I ask him this week why it is...

 

You would need to ask him why as none of us can see the reason for it.

Mark

 

No reason, Romain says he never had problems with a 0.4 gap...

So i don't know about this, 80% on here gaps at ±0.6 to 0.7