cutting up under boost

[black97spyder]

Just got my 97 awd talon up and running yesterday and was driving today. If I get under boost too fast in like first gear, the car sputters and backfires then clears up if I keep my foot in it. If I roll into boost its fine until above 6k rpm then it misfires. This happens at stock boost on my 20g (10psi) or at 15psi.

Could it be a boost leak, even though the gauge doesnt wobble or move?

Or would it be spark or fuel related? Im not sure where to check first or if anyone else has had similar problems?

 

[clipto]

Boost leak tune injector size stock injectors are not ganna do it. Save up for ecmlink sell your old ps3 or xbox. The bigger the turbo the more air it will flow over stock turbo. You need get some more things done. Check sparkplugs too and u got a walbro 255?

 

[black97spyder]

I just installed a 190 and rewired it before I got it running while I was changing everything at once.

Im also going to pull the plugs check inspect them and regap them to .25

It has done it like 6 times out of probly 12 pulls and the only clean pulls were interrupted at the higher rpm. I have gotten like three 1st-most of 3rd pulls without anything and it pulls very hard with the new fuel pump and fmic that were installed.

link v3 is next on my list, its just saving for it is gonna take a month or two :/

 

[talontorque]

I had the same problem as you and mine turned out to be a boost leak

 

[2gmitsueclipse]

What size injectors are you running?

What is your wide-band reading when this happens? (I assume you have this I hope)

What, if any, tuning/logging are you using?

If you have just gotten the car up and running, a boost leak test should have already been done.

 

[black97spyder]

All I/c connections were sprayed with hairspray and tightened very good.

I have a lc-1 wideband but have to still install it in the next few days.

im running stock injectors with no tuning software (I know this isn't right but im not a novice when it comes to cars).

It seems like a boost leak but the gauge doesnt move like it normally does when I have a boost leak. It seems to be fuel or spark related

 

[inthemidst]

I will second what clipto said.Bigger turbo means your air flow sensor is detecting more air flow.You are hitting fuel cut.You need something to tune with and bigger injectors.

 

[black97spyder]

I know I need dsmlink and bigger injectors but justin told me that there shouldn't be that much of difference until 20+ psi.

and still doesn't explain why it has quit doing it on me the more i drive it. Got on it 3 times earlier and it didnt do it once?

 

[MALaCasse]

Do a boost leak test.

 

[Dsmkauai]

If you just installed a bunch of parts mainly the fmic. Do a boost leak test you never know until you have a leak till you do. Also I see you said around 10psi and then mention 15psi. Well 15psi on a 20g with stock injectors and no tune your definitely hitting fuel cut or right at the edge of hitting it. Get some bigger injectors and a way to tune before you melt the inside of your motor from running lean!

 

[2gmitsueclipse]

All I/c connections were sprayed with hairspray and tightened very good.

I have a lc-1 wideband but have to still install it in the next few days.

im running stock injectors with no tuning software (I know this isn't right but im not a novice when it comes to cars).

It seems like a boost leak but the gauge doesnt move like it normally does when I have a boost leak. It seems to be fuel or spark related

Just because you sprayed your connections does not mean you do not have a boost leak. The boost leak test is one of the first things to check to rule out a possible issue. Stop questioning it and just do it.

Take it easy on the car until you install that wide-band, fuel to feed that turbo, and a way to tune for your new modifications.

The stock turbo runs out of breath much sooner than your new 20g. One thing to consider is that the 20g flows MUCH more air than the stock turbo. Your stock fuel setup cannot keep up with demand.

 

[black97spyder]

If you just installed a bunch of parts mainly the fmic. Do a boost leak test you never know until you have a leak till you do. Also I see you said around 10psi and then mention 15psi. Well 15psi on a 20g with stock injectors and no tune your definitely hitting fuel cut or right at the edge of hitting it. Get some bigger injectors and a way to tune before you melt the inside of your motor from running lean!

Its a full forged internal motor, i wont mess anything up other than rings from excessive knock which I know I have some. A BLT is planned for tomorrow but I dont expect to find any leaks, have had many boost leaks in the past and every time my gauge will wobble instead of reading solid.

I am well aware of this turbo flowing more than the stock one because the turbo that is on it now was a 16g and is now a 20g that was upgraded by Justin a week ago. And there shouldn't be that much of a flow difference between the two because it didnt do what its doing now with the 16g, before it was upgraded And I know its not fuel cut because it will do it at 10psi and at 16psi. At 10psi I should not hit fuel cut especially with a rewired 190 walbro. This is why im leaning towards a spark or fuel.

I will rule out boost leaks tomorrow and install my wideband within the next week to rule those two things out.

I have all the supporting mods except for dsmlink and bigger injectors so I should not see a MAJOR tuning issue like I am. It has got to be as simple as a boost leak, blowing the spark out or being too lean/rich.

 

[bigbird94]

What spark plugs are in the car? You NEED NGK bpr7es plugs gapped .28-30!!!

Other considrations: boost leak, Id put this on the Need list as well, clogged/bad injectors, fuel pump over running stock regulator/wrong fuel pressure, pre-turbine exhaust leak ( cheap manifold/turbine gaskets often go quickly especially when they're ported, mecahnical or electrical ignition timing, you will also NEED to set base timing to 5* before tdc.

After that buy link or get a 98/99 black box ecu and get it flashed. A quality tuning device should be the first mod on any DSM. Some 1200cc+ injectors will be required to max that 20g on e85.

I would stay out of boost until these considerations are taken.

 

[black97spyder]

I have bpr7es's gapped at .28... it seems to me its doing what you said, I think my rewired 190 wally is overrunning the stock fpr, because after I boost stock psi or 15 I will smell a bunch of gas.

The main things I changed was installing a punishment fmic, got my 16g converted to a 20g by Justin (who told me it wont really flow more than the 16g until 20+ psi, and car ran GREAT with the 16g) and put a wally in tank 190 in it and rewired the fuel pump.

I also have a lc-1 wideband ready to be installed so I can monitor my a/f ratio, I just haven't had time yet due to finals in college

 

[Dsmkauai]

The 190 won't over run the stock fpr. And I doubt at all that your running rich bro. Your leaned out running 450's with a 20g and no way to tune. The 20g flows way more than the 16g even at low boost. If you ran 14 psi on a 16g with no issues expect to only get 10-12psi out of the 20g without issues, that's the difference in airflow bro. Trust me I've been around these cars for a long time and seen it over and over again on here. Just adding a 190 pump isn't going to do it bro. Your car is the same as everyone else's, I couldn't even push 16psi with my small 16g on the stock 450's and a rewired 190 without issues, the 450's simply cannot keep up. You need to get the proper mods to handle the 20g or you will keep having issues and probably get worse. And what's the result of your boost leak test? How many leaks you find?

 

[black97spyder]

There was one tiny leak at the bov flange of my punishment racing uicp. It was the inner hole on the flange for the gready type rs the fmic comes with. Waiting on the rtv to dry in the inner holes then I will test it again and see how long I can hold the pressure... even with the leak, I could fill it to 5 psi and it would still hold pressure for a good minute before it was back to 0psi on the gauge.

and I was getting 15 psi out of the 16g with no issue with stock fuel pump that wasn't rewired. So I would expect it to at least be good at the wastegate pressure of 10 psi with a rewired 190 now

also pulled the plugs and they all looked great. But were gapped kinda wide at .30 (coulda swore I gapped them to .28) so I re gapped them to .25 and put them back in

 

[Dsmkauai]

Ya you should be able to get 10psi but every car is alittle different. And you need to do a boost leak to like 20-25psi not just 5psi that's not going to show you the real leaks. Also is the bov properly adjusted? That could be part of your problem it could be blowing open to easy and leaking boost.

 

[black97spyder]

No the bov is fine, im using a 1g and have NEVER had an issue with it over the past 4 years. And I know I need BLT test it higher but I wanted to fix the obvious one before I really pressurized it up.

The only connection im worried about is the L pipe that comes directly off the cold side of the I/c core. I had to cut like 3" off to make everything route right with my auto. When I cut it, it took off the bulge at one end of the pipe so it will be easier foe that connection to leak than the rest. But with how well it was holding pressure I know I dont have any other leaks than the one I jus fixed

 

[Dsmkauai]

That's good bro well test it to 20psi atleast because its the only way you will know. And if you pull the pipe off you can make a new bead for the coupler. I use a pair of vice grips and a washer to make new beads when I'm at home, but I have a nice bead roller at my shop now so its much easier.

 

[black97spyder]

Yeah if i have problems with that one connection then I will take it to the local aluminum welding shop and have him run a nice bead around it.

still waiting on the rtv to dry so I don't mess up my attempt to fix the boost leak... I knew something was off yesterday because my 1g bov sounded sequential (which sounded awesome) but wasnt the same bov sound it has always made

how do you make a new bead with vicegrips and a wahser??

 

[Dsmkauai]

Very carefully
http://www.dsmtuners.com/forums/art...7563-how-bead-your-own-intercooler-pipes.html

 

[black97spyder]

Thats pretty neat!!

 

[black97spyder]

So guys I have kind of narrowed the cause down. The car only misfires/stutters when trying to boost too fast in 1st gear or 2nd. If I roll into the boost I have absolutely no problems 1st through 3rd gear at 14psi.

Well I did my BLT up to 18psi and came up with 3 small leaks and two bigger ones. One is at the jpipe nipple for the boost controller on the I/c piping. the other two small leaks were where the jpipe meets the u-pipe on my punishment racing fmic. Then I fixed the jpipe to u-pipe leak and was able to do a BLT to 22psi.

One of the bigger leaks was at the inner hole of the bov flange so I rtv'd that and let it set and its good to go now.

now its on to the last two leaks. One is my jpipe nipple, would I uncrew it and blue loctight it or use something else to seal it?

the worst one of all is my jpipe to turbo connection. It looks to be leaking PRETTY BAD... how should I go about sealing that flange? Should I try a different kind/style of gasket? Or should I put some rtv around the sealing flange and let it set overnight?

I think this connection could be my problem which is causing boost leak symptoms, like when an I/c coupler blows off and then reseals when you let out off the gas

 

[hotrodssnova]

Its a full forged internal motor, i wont mess anything up other than rings from excessive knock which I know I have some.


You will also hammer your rod bearings to the point they will loosen up and spin in the bore. Drop the boost to a stock level or less, get bigger injectors, and tune it. Knock should not be ignored.

 

[black97spyder]

I am well aware but knock isnt my problem. I had my stock side mount on my 16g at 16psi and it was firecracker hot after a 1st-2nd gear pull so my knock was ALOT more then it is now with my fmic and new fuel pump.

my problem is something simple but I just havent pin pointed it yet. Ive been running a similar setup on dsms without tuning devices for years (I know this isnt proper)