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Discussion Starter · #1 ·
Hey guys,

Got a 33 GTST, and I'm having a boost issue under heavy load around 5.5k feels like its spluttering/missing etc. Its happened after installing a FMIC? Now, I've checked all the pipes and doesn't seem to be any leaks, I also swapped out old plugs with some new 0.8s and the car came with Splitfires so not sure how old they are. I cleaned the MAF today, along with taking the coils out and giving them a good inspection and clean and they look fine. I also did a compression test whilst these were all out and results were fine. What more can I try before I start replacing things? I also disconnected the battery to see if the ECU reset could work with the increased air going in but again, still splutters :/

I'm not sure if its linked, however on startup car starts fine the shoots up to close to 2k revs and within seconds dies down and idles normal. But, starting the car from warm it can cough and then do the opposite and idle low, I replaced temp sensor and that it on that end but not sure if any of its linked lol.

Cheers everyone! :)
James
 

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Are you still on standard ecu if so a good place to start is checking you boost pressure you could be hitting a boost cut at about 1 bar .
Also Check for a fuel pressure drop when the miss occurs , could have a failing fuel pump , clogged filter or bad reg .
 

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Discussion Starter · #3 ·
Are you still on standard ecu if so a good place to start is checking you boost pressure you could be hitting a boost cut at about 1 bar .
Also Check for a fuel pressure drop when the miss occurs , could have a failing fuel pump , clogged filter or bad reg .
Hey mate, yes standard ECU, standard Turbo so runs about 0.5 bad I think, I have a boost gauge so I’ll try and keep an eye on it under boost. Fuel filter was changed about 3 weeks ago so can rule that one out. May have to look at the reg and pump next.

Thanks bud!
James
 

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Things that affect engine under load...and especially under boost are coil packs even it they look OK they can still track if they are old, heat range 8 on a std engine is totally unnecessary you should be on std or just one grade colder this won't help.

The fact that you have fitted a new presumably bigger FMIC will without doubt give rise to an increase in dense cold air with in turn can make things run leaner which in turn will lead to misfire although the std over rich fuelling should cope with a small increase if it's a big IC there may be too much cold dense air for the fuel to compensate.

Other things to look for are vacuum leaks on the FPR line and also check the FPR static pressure if the IC is causing this you can fit and adjustable FPR and raise it slightly as an interim measure until you get an ECU remap etc
 

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Discussion Starter · #5 ·
Things that affect engine under load...and especially under boost are coil packs even it they look OK they can still track if they are old, heat range 8 on a std engine is totally unnecessary you should be on std or just one grade colder this won't help.

The fact that you have fitted a new presumably bigger FMIC will without doubt give rise to an increase in dense cold air with in turn can make things run leaner which in turn will lead to misfire although the std over rich fuelling should cope with a small increase if it's a big IC there may be too much cold dense air for the fuel to compensate.

Other things to look for are vacuum leaks on the FPR line and also check the FPR static pressure if the IC is causing this you can fit and adjustable FPR and raise it slightly as an interim measure until you get an ECU remap etc
Thanks mate! I’ll deffo look for any leaks. I have a set of 1.1 plugs I could always pop back in.
If nothing, I’ll look at getting a minor ECU map in the future.
👍👊🏻
 

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I’d go to coils first. Especially with stock turbo.I went through same issues and fixes before, only to restart at coils. Liquid tape around metal coil-body and die electric grease at boot connector and problem solved. Just my 2 cents. Good luck!
 

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Discussion Starter · #7 ·
I’d go to coils first. Especially with stock turbo.I went through same issues and fixes before, only to restart at coils. Liquid tape around metal coil-body and die electric grease at boot connector and problem solved. Just my 2 cents. Good luck!
Tried Die electric grease and cleaning up my current coils, still no joy! Got some replacement coils coming today so fingers crossed its them!

Cheers mate!
 
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