missfire at higher than 5 psi of boost need help!

[98gstbrad]

Ok so heres the rundown. I have a missfire when i hit over 5 psi of boost, car is all stock and here is what i have come up with for the reason for problems. I know i have a small boost leak in my uicp (upper intercooler piping) and at first i could not boost at all so i pulled the plugs. They seemed to be in need of a change so i replaced them with the proper ngk plugs gapped to stock 32. Then i could hit 5 psi after that so then i got the code scanned again both times it has said cylinder 4 misfire. So to make sure it was the wire i moved the 4 wire to 2, the 2 wire to 4, and left the 3 wire and 1 wire now. Its still having the same problems but it wont set a misfire code. What could it possibly be and i Do not think it is the coil packs please give me some ideas and when i say stock car i mean stock unmolested in all ways.

 

[habitatguy187]

Spark plugs should be gapped to about .028, but it's not going to fix your problem. The problem is most likely your boost leak, fix it and see what happens.

 

[98gstbrad]

im trying to but i cant seem to find many upper intercooler pipes for my car

 

[dsmsleeeper]

Start at the turbo tightening the couplers and continue till you get to the intake. Just take your time Boost leaks are common and describe the symptoms you are having.

 

[GRAVEDIGGER]

I know i have a small boost leak in my uicp (upper intercooler piping) i replaced them with the proper ngk plugs gapped to stock 32.

You know you have a boost leak, so fix it. It will continue to give you problems until you fix it.

Spark plugs should be gapped to about .028, but it's not going to fix your problem. The problem is most likely your boost leak, fix it and see what happens.

Yeah, they should be gapped to .028 and I don't really think it would resolve the situation, I'm sure it wouldn't hurt.

im trying to but i cant seem to find many upper intercooler pipes for my car

Either fix what you've got, or get a different one, but you know what you need to do. Good luck!

 

[98gstbrad]

Ok so boost leak may cause it ill get that fixed as soon as possible. Thanks for the help guys.

 

[rEclipserGST]

I would take a picture of where it is leaking from. So we can further assist you on if you need to just tighten then clamp, or replace the coupler or pipe itself.

But other than that, .028 for the spark plug gap.

Please get a boost leak tester as well.

 

[98gstbrad]

I have a boost leak tester and i know where it is exactly. I am trying to figure out how to get pictures on to here at the moment. So until i do here is my description: The leak is on the stock upper intercooler pipe that has the blow off valve on it. On that pipe speciffically it is at the mounting bracket of that pipe and the leak is about the size of a dime cut in half.

 

[stuckwithgsx]

That's a big leak. No good at all.

Also check your ignition control module. It's the electronic sensor right next to your ignition coil. Make sure it's got a good connection.

 

[arcuri21]

I would check the injector seals, and what maf are you running.. stock?

Also you can either order new gaskets all around, or copper spray them a lot.

 

[98gstbrad]

I am running a stock maf sensor and injector seals are all good.

Now the ignition control module is one that i have not heard yet how would i go about checking that?

 

[rEclipserGST]

That boost leak is gigantic. Think about it. Your car is programmed to rune WITHOUT a boostleak while IN boost. So your car is gonna run garbo. You need to fix that Boostleak asap!

That could easily be the reason why your car is misfiring. You are losing air AFTER the MAF, which is causing the car to run richer, flooding the cylinders possibly. Triggering misfire.

Fix that first before looking for other problems. It is a snowball effect with a boostleak.

I'm guessing you have the stock 2g plastic bov? Do yourself a favor, and at least order a 1g bov with an adapter to match your stock piping still. Easy to find and you shouldnt spend more than 60 bucks shipped for BOTH.

 

[eli96talon]

Im having the same issue as the OP except my misfire is on cylinder 3.these are the things I've tried to fix mine maybe it will help you. Change spark plugs,spark plug wire,diffrent coil pack,ignitor,maf sensor,fuel filter,checked timing belt,checked ecu,found boost leaks but once fixed didn't help misfire,checked injector with noid light,and checked for good spark on wires...with all this done I still can't get the car to stop misfiring on cylinder 3.as long as my car is not in boost it drives just fine,as soon as I boost it at 10lbs or more a few times it will misfire.once the car cools down it I let it idle for a few sec. It stops the misifre.is your issue kind of like this?

 

[98gstbrad]

Yes its kind of like that and it wasnt gradual. I was driving it and it was boosting completely normal, running great. Then all of the sudden i drive it again and it just does it immediately. Right now i have plugged the boost leak mostly, I have changed the plugs, checked the injectors, and have moved the wires. Nothing seemed to work so now i cant get the code to be set again so i cant see if the missfire follows the wire... I am going to check the wires to see if they have the correct resistance in them next. After that i will most likely go ahead and take the same route that you took.

I have already changed out the bov its a greddy type s I believe.

 

[MichaelSuch]

I had a similar issue, would only missfire during WOT above 3,000 rpms. A few months later I ended up running only on two cylinders. Coil pack was bad. Replaced the coil pack, started running on all 4 and that also fixed the missfire issue under boost.

 

[eli96talon]

What cylinder are you misfiring on? Check the spark plug to see if the gap is closing on its own,or if it looks beat up.I've been working on my issue all day,now I finally figured out what is wrong with mine.it seems there was a small piece of metal in my intercooler piping and it finally found its way into cylinder 3.after the car gets high in the rpm range where im making boost that's where the piece of metal starts hiting the spark plug till it closes the gap and my car misfires.also my comp. On all cylinders is 185,but on cylinder 3 its 160 so that let's me know that the valve go chewed up by whatever fell in there,or the piece of metal is keeping the valve open.good thing it only take less than an hour to pull the head.

 

[98gstbrad]

All spark plugs look fine. Glad you figured out your problem.

 

[98gstbrad]

Ok so i figured it out! The boost leak caused the hesitation at high boost. The spark plug wires caused the misfire on cylinder 4. The ignitor caused the misfire across the whole board that i could not track. multiple issues multiple fixes. But i can say one thing it was a heck of a way to learn how to diagnose isnition issues. Thanks for all the advice on things to check guys!

 

[ENICKB]

Go with ngk 7's and gap em to .27 and no problems ever again! And always remember to do a boost leak test before thinking anything else is broken! Percs of having a turbo car!

 

[92awddsm]

Go with ngk 7's and gap em to .27 and no problems ever again! And always remember to do a boost leak test before thinking anything else is broken! Percs of having a turbo car!

Stock car=ngk bpr6es gapped @ .028"