Issues with Fuel/Boosting?

[InfiniteGSX]

Ever since I put my new motor in, I've been having an issue. I can drive the car normal and it drives fine. But when I boost it, it will pop in the exhaust, like its sputtering, and slam you to the seat, and then hesitate and pop again. When its sputtering it throws some smoke, not heavy smoke. But I can tell it has smoke.

I changed wires and plugs, Still no change. Last night I took my girlfriend to see the river of lights, its a light show at the Albuquerque Botanical Gardens, For xmas... when I got back I popped the hood and the exhaust and hot side of the turbo was glowing! I've never seen that before on my car. Before the new motor, it was boosting fine.

Can someone help me out.

 

[DSM1G90]

What about your timing specs? What about A/F ratio? Sound like, when you boost, you suddenly go into super lean mode.

When you did plugs, what did they look like? sooty black (running rich), tan color (normal) or super white (lean and/or too hot of plug)?

What color is the smoke? Black-running rich. Blue-oil burner, White-turbo issue.

Wonder if you got some sort of air leakage of sorts that is entering in the manifold (do this trick: when in idle, squirt WD40 around where air could sneak in, esp around the intake manifold. If you suddenly get high idle run up, you got a leak of sorts)

some tips that I've done before. Maybe this will work, maybe not..but it's worth a try.

Good luck-DSM

 

[InfiniteGSX]

I've already gone through boost leaks. The Plugs... I honestly don't remember. They are still being used in my friends car and his are running fine. The smoke.... I don't know, smoke is smoke. I've never seen smoke with a color.

The car is killing fuel tho. My friend says its running super lean. And I know before I got the car I had to replace the hotside of the stock turbo because it was melted.

I don't know what the A/F Ratio is. I cannot hookup my logger right now because someone stole my cable. And I Just ordered a LC1.

Think of stuff you go through when you do a motor swap, because the car was not doing this on the last motor. It has been doing it the entire time on this motor... Could it be a grounding issue? Could it be I missed something when plugging the harness up?

Timing it is perfect. Timing Belt is on 100% perfect, a first for me. But everything lines up perfect. Ign Timing, I grounded the wire, Adjusted the cas with the biss screw to set base timing to +5* @850rpm

The car runs great. No problems idling. No problems driving. Its only during boost when things go to shit...

 

[carpethead10]

How much boost you running? Is your fuel system up to par? Sounds like you are leaning out and detonating.

Get a new cable for your logger

 

[91TSIallday]

what about your injector seals/ injectors themself? I had some seals go bad on one or 2 and i was doing the same thing minus the turbo glowing

 

[InfiniteGSX]

I'm running off the wastegate. So 10psi. fuel System is a Walbro 255lph fuel pump, stock everything else. 2g 450cc injectors. About to go to a stock fuel pump. Car is somewhat being reverted back to stock for a year or so. I need a daily driver.

 

[91TSIallday]

the wally could be over powering your injectors giving you a fuel cut effect. go back to stock fuel pump and try that

 

[InfiniteGSX]

yeah I'm going to anyways. Just cause I want the car to run right, right now... But the walbro isn't new. So why would this problem just start when I put in a new motor? Car boosted fine on the previous motor....... And this motor is in better condition. So this has to be something involving the swap... Maybe something I didn't do... or connect...

 

[91TSIallday]

go through the car if the problem is still happening when you go back to the stock FP, make sure that all hoses, couplers and seal is good and not lose or off.

 

[InfiniteGSX]

IT can't be the fuel pump honestly. There is no way because the car came with the fuel pump and I've been on 2 other motors including the stock motor and it ran fine and had power and didn't hesitate like this...

Well Update. I Went through some crap. There was a ground wire that connects to the chassis behind the intake that I had grounded to the intake. I put that back onto the chassis like its supposed to be, I made my own ground kit. long bolt bolting down a couple 4ga wires, one I bolted to the CAS, the other to the intake manifold on the back side (like stock). One goes from the chassis to the trans (but thats the stock black/yellow/ wire. And then the batteries 2ga grounds to all these wires at the chassis.

During this, I fixed a broken wire on the knock sensor. The knock sensor plug is 2 wires, Red was cut in half. So I was working on fixing this. When the black/white wire just pulled out of the sleeve going to the knock sensor. Are our knock sensors two wires or one. And if one, what the hell is this other wire for? It didn't go to the knock sensor, only halfway through the wiring.

I also found a bad wastegate flapper. It wasn't closing all the way (bad adjustment on the adjustable bar), and when it was opening it was sliding down the shaft causing it to get stuck fully open. I disconnected everything and tac welded the shaft where it should be, and adjusted the wastegate fully to hold the flapper shut. Now it boosts soo much better but still hesitates.

What it does, Is it will boost fast to 8psi, then creep up to like 15 or whatever and when its doing this it will hesitate and sputter.

I've honestly never experienced anything like this so thats why I'm asking here. I've checked boost leaks and fixed them. I do have one small exhaust leak above the turbo where it mates with the exhaust manifold, but I've had it forever and it never caused an issue like this.

And I don't have any way to data log it yet, while driving. I'm about to try a laptop with a power cord tomorrow just during idle. But dunno if it would have a code saved for whats going on. I have gone through 3/4ths of a tank, and only at 150 miles on the odo. So I'll just guess, 200 miles to the tank... I honestly can't believe that... Thats horrid!

 

[DSMopar]

You're hitting fuel cut dude, check for boost leaks.

Also list your mods, if you're running the turbo in your profile then no shit you're going to fuel cut @ 15ish psi.

As far as your gas mileage, ya what do you expect with a 255 and no AFPR? You're overrunning your stock FPR and are fat across the map...

 

[slow4g6392tsi]

Umb, creeping to 15psi and possibly higher on a 60 trim and stock injectors? Too much air, not enough fuel! Lucky it hasn't blown up yet, especially with the cut wire to the knock sensor.

Pretty much exactly what DSMopar said.

 

[InfiniteGSX]

Oh non of that shit is there anymore. Car is practically stock now. Walbro 255, 3" turbo back, big 16g, thats it! And I don't know what the boost is actually set to, cause it hasn't hit a specific number and stayed there! I bought the car with a 14b set to 15psi and this exact exhaust and the walbro so it cannot be that! Cause this problem JUST started when I did the new motor install. It hasn't been going on for the past two years. Only the past two months.

And why would I start hitting fuel cut soo f'n fast? I used to boost to 18psi before with no cut. I'd only receive fuel cut at 20psi. Never around 15psi. I used to daily that!

 

[DSMopar]

Ok big 16g, still too much air. I fuel cut on my STOCK 14b with the simple mods listed at 16 psi now that it's cold as #### (at night in the 40's) fuel cut is all about air flow.

Why is it doing it now? Well you said you had a 14b on it, now you have a big16g.... there you go. Furthermore like I said the ambient temp has alot to do with it. It's cold as shit across the country now which means way more dense air and more mass flow rate at the same boost pressure previously.

 

[Dsmj89]

Furthermore like I said the ambient temp has alot to do with it. It's cold as shit across the country now which means way more dense air and more mass flow rate at the same boost pressure previously.

+2. I run a evo3 16g and i as well experienced fuel cut a few times.
I would fuel cut at 19-20 psi with temps in the high 70s at night, this was like 3 months ago.
Just recently like a month ago one night it was in the 50s and i took the car for a pull and it fuel cutted at 15, i wasn't surprised...

So as dsmopar said, the ambien air temps could be playing a big roll with your fuel cut problem.

 

[InfiniteGSX]

Ok ok lets just stop here...

So the car just wanted to start having problems for no damn reason? Big 16g on my last motor, No issues. My stock motor had a bunch of large turbo's and NEVER experienced fuel cut! So now my car randomly just decided in its eprom mind, that it wants to fuel cut for the #### of it. No reason...? Just going on strike?

Are you guys honestly going to tell me this? And since when is a 16g too much? That deletes everything everyone on the face of the planet in the dsm world has been doing. 16g is the most used turbo! I've used a 16g for the past year with no issues. My best friend has a 16g on his and he's doing 19psi with not a single issue except traction. My other friends completely stock GST on 18psi on a 16g is NOT causing fuel cut. But my car randomly feels like only allowing 8 psi, and creeping up to 15 and it thought in its mind it will piss me off and cut fuel.

I'm sorry but I'm going to have to ask for someone else to give opinions.

14b @ 18psi... No Fuel Cut EVER! 1st Motor
16g @ 10psi... No Fuel Cut EVER! 1st & 2nd Motor
16g @ 18psi... No Fuel Cut EVER! 1st & 2nd Motor
16g @ 8psi... Creeping to 15psi and "cutting fuel" on its way to 15psi! 3rd Motor!

255 is the reason my car felt like eating fuel out of the blue? 255 has been on the car before I owned it! I used to get 300 miles or so to the tank! Now I just got 176! This was taken an hour ago!

1st And 2nd Motor... 300 miles to the tank!
3rd Motor... 176! SAME MODS! 255, 16g, 3" Exhaust! No different from the last setup, and the setup before that.
THE PROBLEM STARTED IN THE NEW MOTOR, FORGET MY "MODS" OR THE LACK OF MODS. 2ND MOTOR WAS PULLED, 3RD MOTOR WAS INSTALLED! BOOM! PROBLEM BOOSTING! BAD FUEL MILEAGE!

Now with that said, hopefully someone will understand my problem. I finally got TMO working on the car and I can't understand it for nothing in the world. However funny as it is, I checked the engine codes and it said 2.0 Turbo was my only error . TPS was at 18% at idle. I pulled it down to 8% which is as far as it will go. At normal op temp idle was at 850, and timing advance was around 12*. Thats just what TMO said. Thats at idle but isn't it supposed to be at +5*.

BTW not meaning to come off as a dick, I just think there is too much misinformation here.

 

[JFZERO ECLIPSE]

Yes its suppose to be at +5* did you happen to forget to ground the plug the that deals with ignition timing on the firewall? I know I dicked with timing before without grounding out the plug and it completely messed with timing way too much....loggers cant be used to dial in timing (I THINK)...

Whats your compression? just wondering? you said no boost leaks... trying to think what else could it be....

For the TPS is your throttle cable possibly too tight???disconnect it and see if it drops down...You wont have to dick with the adjustment at all...otherwise you may have to slightly rotate the TPS to get it to read 0...(Some loggers actually read the TPS as being higher than what it is though...just checking though...)

 

[InfiniteGSX]

Uh, I grounded the wire and set it at +5*. Then I had to do my timing belt cause of a water pump failure. But I got all marks 100% dialed in. I am thinkin of doing timing again to make sure. I've heard people tell me to do timing with a logger. But I never have. I did it with a timing light. BUT, I may have screwed up cause of a bad view on the mark. I'll redo timing after I Drive it for 30 minutes and mark the crank pulley with white out.

I rebuilt the TB so TPS hasn't been set right, I just put it in the middle cause thats where it looked like it was when I pulled it off. When I adjusted it, I adjusted it as FAR as it will go counter clockwise and it showed up on the TMO logger, 8%. And no the throttle cable isn't tight, its actually a little too loose in my honest opinion. I don't think I could get it to 100%. but ehh.

Haven't done compression yet. But maybe when I go into town to do timing I can do the compression to check.

Next log I do, will be with a Palm Emulator and MMCD. Cause IDK wtf that 2.0 Turbo Error means haha. Unless TMO is tellin me the car itself is the error haha. I almost wanna put in a non tampered with TB to see.

I know vacuum is good. My first motor did 18inHG at idle, this one does 17inHG. Last did 11inHG. But the first motor, and second motor I couldn't rev like this one, its sooooo smooth. the old motors felt like they were going to blow up if I reved to hight. This one just does it.

 

[DSMopar]

Are you guys honestly going to tell me this? And since when is a 16g too much? That deletes everything everyone on the face of the planet in the dsm world has been doing. 16g is the most used turbo! I've used a 16g for the past year with no issues. My best friend has a 16g on his and he's doing 19psi with not a single issue except traction. My other friends completely stock GST on 18psi on a 16g is NOT causing fuel cut. But my car randomly feels like only allowing 8 psi, and creeping up to 15 and it thought in its mind it will piss me off and cut fuel.

I'm sorry but I'm going to have to ask for someone else to give opinions.

What mods did they have? Many eliminate fuel cut with Eproms etc....

14b @ 18psi... No Fuel Cut EVER! 1st Motor
16g @ 10psi... No Fuel Cut EVER! 1st & 2nd Motor
16g @ 18psi... No Fuel Cut EVER! 1st & 2nd Motor
16g @ 8psi... Creeping to 15psi and "cutting fuel" on its way to 15psi! 3rd Motor!

At what temperatures was this done at?

Why do you keep swapping motors? Keep in mind a shitty motor will flow less air at higher PSI, thus no fuel cut...

So what's in this 'new' motor?

 

[InfiniteGSX]

Ok. First motor died because my stupid ass. I crushed the water/oil cooler and thought it was the head gasket. So I replaced the head gasket and thought all was well, it fried the rings a week later from overheating cause of coolant/oil mixture.

2nd Motor was a "built" motor haha... It was claimed to be built but it was just rebuilt and I picked it up for a trade for some stuff. It had ARP's, MLS, BS Removed and thats it. About 80 miles into the motor it fried every ring.


This new motor I'm on is stock 180k mile motor out of a 91 Auto AWD. It revs free unlike the other motors. It seemed like everytime I'd rev it, it was being restrictive if you know what I mean. BUT, The first motor boosted just fine. I had the first motor setup to 18psi on a 14b and then 15psi on big 16g. And it roasted the tires and all of that. It never had an issue like this. 2nd motor.... it boosted but I never attempted a launch out of it and I didn't boost it hard or anything cause I thought I was in break in stages... more like break it stages. But it didn't hesitate. this motor revs just fine even tho I don't try to rev it... But I have gone to play in snow and stuff like that and it revs great and smooth. A little too fast for me . It makes me afraid to over rev it.

When I did that TPS Adjustment, It now boosts better, BUT it still shudders a little. I think... Possibly I might have found my creeping problem... dunno tho... Downpipe bolts were coming loose and the downpipe was leaking exhaust bad. So I'm gonna try to tighten it down and see if that helps stop the creep.

And mods... Well one guy didn't have much of anything, it was a stock GST with a 16g. Now he has support mods. This other kid with a 90 gst has nothing except a big 16g set to 16psi. His car is completely stock. And my car has an eprom! 94 Federal.

COULD, any of this have to do with anything involving the TB? The CAS? Timing? TPS Adjustment? uhm... IDK... Any of that?

I'm gonna go do timing on it again.

***EDIT*** Timing is dead on!

 

[DSMopar]

18 psi on a 16g with stock sidemount and stock exhaust won't flow shit.

Someday you'll understand you're just flowing too much air now .

 

[InfiniteGSX]

AHAHA.... Wow I can't stop laughing at the responses I'm getting. I guess I was right, my car is on strike. Since nobody here can read simple English. Sorry. I am not on a stock exhaust. And I have NEVER had any sort of issue with the 3 16g's I've ran before this.

Maybe one day you'll start understanding that!

19psi right now on STOCK Fuel Pump, Stock Motor, Stock Sidemount and 3" TURBO BACK EXHAUST FLOWS FINE! There is nothing wrong with the car now. The problem was TPS. But nobody said that. I am now boosting just fine at 15psi and I cranked it to 20 and it cut at 20 exactly. 19psi did just fine. But I have my adjustable wastegate set to 15psi and I'm now on a brand new stock fuel pump....

Thanks for telling me my car is on strike and didn't wanna work right because its PMS'ing.

This thread is done! Shows me for putting my car back to stock. Should have just sold it and bought a stock one.

 

[DSMopar]

Fail to see how the TPS would cause your symptoms. Sounds more like you fixed a boost leak in the process of replacing it .

 

[PieEyedPiper]

Fail to see how the TPS would cause your symptoms. Sounds more like you fixed a boost leak in the process of replacing it .

^^ This.
I'm pretty appalled by some of the attitude in here, that and that the OP has no problem with running a 16g up to 19-20psi with stock 450's.

Either way, glad its running well again.

 

[ballersixty9]

had this problem and it was my ecu the caps were leaking chack that