So what did you install in place of the bcs restrictor? What boost is the car running at? How high did you blt? Are all your sensors and connections on? Any CEL?

I just pulled the little pill type thing out of one of the inlets and plugged the hose back in, I believe 10-12psi, no boost gauge installed yet, all my sensors and connections are good, and no CEL

Assuming that you did a correct boost leak test, I would lean next towards ignition. You have no fuel mods so I don't think the issue lies there. I would say to go back over your boost leak test. So many people get on here saying that they've done a thorough BLT and just kinda gave it a visual once over to call it good. As far as your PSI goes, you have to get a gauge to be 100% sure. Your " I believe 10-12 psi" could very well not be 10-12PSI.

If your BLT checks out, then I would lean towards checking your ignition system; plugs, wires, etc.

Your not at 10-12 bro. The car stock runs 14 and taking the pill out can bump you up to 15-16 just depends on car. And with no fuel mods or way to see anything your doing, you might be hitting fuel cut. or you have a boost leak over 10-12psi, do another blt to 15-16psi and check all over.

Hell I thought stock PSI was 10psi, and doing the BCS Restrictor delete put it in the 10-12psi range

My guess is still a boost leak. Removing the restrictor will help it peak at about 15, but settles back down to about 12-13 max. The stock system should be able to handle that load. Pay special attention to couplers, throttle body shaft seals, and injector seals.

After that, I would look to plugs and wires. A fresh fuel filter could be in order if all else checks out.

Trying to make my first BL tester. Saw instructions on VFAQ. I got the 1.5 id cap, but when I looked for 2.5 od rubber hose as specified, but the cap won't fit in. How about what id hose should I use? My car is bone stock except for a new boost gauge.

Plumbing couplers will be your friend.
Here is a walk through to make one with readily available parts. I found more of the parts I needed from smaller chain hardware store like Ace or Aco than at Home Depot.

If you build it, leaks will show.

Here is how to use your new tool:

I apologize, I hijacked the thread so to speak.

ZsGST,
I couldn't find a DSM profile for you. Does the car have a stock T25 turbo, or has it been upgraded? That could give you some clues on whether you're hitting fuel cut or not.

boost leak or plugs/wires

T25 stock turbo

Thank you 2gmitsueclipse!

Doing a plug and wire change tomorrow, will update

Plug and wire change didn't fix the issue. So no boost leak, new plugs and wires, I've been told I need DSMLink to fix this issue. So I gotta shell out 700 bucks? Lol

How bout a video of it happening? When it happens does it feel like you hit a wall so to speak? And you don't need ecmlink to fix Ur issue .

Just to be thorough, when you took out the restrictor, are you absolutely sure the electrical was reconnected and all the hoses went back to the original spots?

Dsmkauai said:

How bout a video of it happening? When it happens does it feel like you hit a wall so to speak? And you don't need ecmlink to fix Ur issue .

Click to expand...

I'll most likely post a video tomorrow when it's sunlight outside. I don't trust doing fifth gear full boost at night on a country road with no street lights. Not that much of a daredevil. And ECMLink was recommended because of the mods I have installed. A friend said I may need it to regulate things.

Mauispyder said:

Just to be thorough, when you took out the restrictor, are you absolutely sure the electrical was reconnected and all the hoses went back to the original spots?

Click to expand...

Absolutely, I was a bit worried about doing the restrictor delete but me and a friend tackled it and were thorough as hell about it, but I'll still take out the CAI tomorrow and double check everything.

Finally managed to catch it on video, this recording was in a fourth gear pull, throttle wide open, and it did it. Like I said, it won't do it if I'm not wide open throttle. Only under a full load. But there's also hesitation between gears.

What the hell is with my mystery hesitation??

I think I'd sh## my pants if my car did that at 80. Get an inexpensive mechanical boost gauge. That engine sounds more than stock or there's more boost happening than estimated. Maybe fuel cut after all. I'm just really paranoid when you make a change and immeadiately get a problem that the change is closely related.

Trust me, first time it did it I was shocked to say the least. Now, when WOT, it's just kind of half expected. Haha
I do have a mechanical boost gauge but no t-fitting to install it, and I'm completely broke right now so can't really go buy one until next week. And next week I'll be out of town for about two weeks.

My 91 does almost the same thing intermittently. It's stock with MBC and I have a boost guage to see with its set to around 16-18 psi and will fuel cut same exactly way yours did in video at wot but usually only in first gear.. keep in mind mines a fwd automatic but it also only does it if motor isn't fully hot when it's hot first gear wot will spike up to 15-16 only but if I roll into it in 2nd or 3rd it goes steady at 18 psi.. I also know I have boost leaks in the exhaust mani with cracks and a bad biss oring.. can't seem to find one anywhere already rebuilt the tb but a last if I were u I'd also consider a MBC to turn down the boost I plan to tweak mine down a tad to stop the fuel cut kinda catches you off guard and not sure about when you shift as I am auto but hope that helps

Well, I'm still completely stuck with my mystery hesitation, a friend says I need to backtrack and remove my CAI and FMIC and go from there to see if it fixes the issue. Says his Ralliart had the same issue with a CAI. Acting funny and whatnot.

The car I built did that at one point when I was playing with the mbc. I think I turned it down and it went away. That was when I first built it though, within first 50 mi break in, I was not at wot either, more like 3/4 throttle in second and not going above 5k rpm. Its never done it since, almost 3000mi now.

That was crazy when it happened though I thought something broke, felt like someone just grabbed the rotating engine to a stop for a second.

Try this, connect the vac line from the turbo strait to the actuator, leave the solenoid plugged in though, this should run it at wastegate setting. I ran ours for awhile cause I thought the cheap mbc was leaking, recently I hooked it back up though and cranked it all the way up, well it never seems top stop but I turned it clockwise for along time...

It still has not done the surge since and hits 15psi but then settles at 13 through through redline. Which I think is just as much as the ol t25 can do.

Honestly it never seems to do much to the boost and I think its a cheap garbage mbc.


I dont think the intake or fmic would cause that, especially if its not all the time wot, just make sure everything is tight. I also dont think youd be hitting fuel cut with stock turbo, or is it stock?