Jolt after building boost in second

[Gst to the max]

Hey, everyone I just recently redone the turbo , header and cold air intake
On my 95gst. I fired it up and it runs amazing for sitting for 5 years. I was going down the road and was feeling throttle happy so I had to see what it had. In first it reaches 14 pounds at about 5500 rmp, second it goes to 11 pounds at 4200rmp then and big jolt happens and u have to let out of the gas. Is that the waste gate kicking in? Or do I have other problems, help. It does this in third to but never in first.

 

[PrimerPLus]

What does the jolt feel like? Like hitting a wall?

 

[Gst to the max]

Yes! That's exactly what it feels like, now granted it doesn't slam your head into the steering wheel but you can deffintaly feel it.

 

[PrimerPLus]

Boost leak. Can be something small. Do a boost leak test. Also it is possible one of your couplers are prying off when it gets to a certain psi level and when you let it back off it re-seals. So do a boost leak test.

I had same slamming into wall feeling and it was because I had a boost leak at the throttle body, bad gasket.

 

[Gst to the max]

I was thinking it was a boost leak. I had to take the motor up out of the car one day, when putting it back in of course I reconnected everything. I went over all my clamps and it didn't do it that day. I'll deffentaily do a boost leak test .. Thanks

 

[PrimerPLus]

Np, let us know how it turns out.

 

[Gst to the max]

Will do, also i have a coolant leak coming from the turbo coolant line, I do believie. Will this result in a boost leak aslo ?

 

[PrimerPLus]

I don't believe so. But it is never good to have a coolant leak.

 

[Gst to the max]

Nope never is, I just haven't found the time to pull the header lose. It's the rear coolant line on the turbo, the not so easy to get to one .

 

[PrimerPLus]

well im sure you will get to it soon

 

[Gst to the max]

Thanks man! Happy boosting

 

[Gst to the max]

In all honesty I've never mad a boost leak tester. Wouldn't Soapy water work ?

 

[perks563]

Fuel cut? You don't have any fuel mods or tuning device listed.

 

[bryanwheat]

In all honesty I've never mad a boost leak tester. Wouldn't Soapy water work ?

Soap and water will work to find the leak but you will need to pressurize the system to be able to do the test.

 

[Gst to the max]

my thought was to start the car, hold it at 1500 rpm. unless you guys have any other suggestions.


i was leaning in the fuel cut way cause it doesnt do it in first! i have no clue im going to start with a boost leak test.

 

[bryanwheat]

my thought was to start the car, hold it at 1500 rpm. unless you guys have any other suggestions.


i was leaning in the fuel cut way cause it doesnt do it in first! i have no clue im going to start with a boost leak test.

That will in no way work, you need 20+ psi in the system to do a boost leak test. Go to home depot buy the parts to build a boost leak tester, put it on the turbo and pressurize it. It is very simple. 2G Turbo DSM Boost Leaks -How to test and fix

 

[GalantStroker]

Something about the symptoms doesn't add up here. At least not in the "boost leak" sense. If he had a boost leak at 11 psi that was causing the car to buck, he should have the same problem in 1st gear but instead he sees 15 psi. Sounds like a fuel issue to me, either fuel cut (for whatever reason) or the ecu is pulling massive amounts of timing for some other reason (i.e. knock)

Might help in the diagnosis to list the supporting equipment.

 

[bryanwheat]

Something about the symptoms doesn't add up here. At least not in the "boost leak" sense. If he had a boost leak at 11 psi that was causing the car to buck, he should have the same problem in 1st gear but instead he sees 15 psi. Sounds like a fuel issue to me, either fuel cut (for whatever reason) or the ecu is pulling massive amounts of timing for some other reason (i.e. knock)

Might help in the diagnosis to list the supporting equipment.

Do you realize that fuel cut has NOTHING to do with the fuel system whatsoever. Fuel cut it caused when you flow a certain amount of air thru the maf sensor. This is caused by running higher boost OR a boost leak. This is common knowledge. Also the reason for this to set in in higher gears is because there is more load on the engine, the load on the engine last's longer in 2n'd gear than it does in 1st.

 

[GSTurbo1]

Yea I think it is a fuel delivery issue... either running too rich or too lean. Could be a boost leak, but I feel that you need some kind of standalone fuel system to deliver what you really need. But to check for a boost leak by something like this off of ebay 3" UNIVERSAL - TURBO BOOST LEAK TESTER - Tests any turbo with a 3" comp. inlet | eBay that should help you pressurize the system

 

[bryanwheat]

Yea I think it is a fuel delivery issue... either running too rich or too lean. Could be a boost leak, but I feel that you need some kind of standalone fuel system to deliver what you really need. But to check for a boost leak by something like this off of ebay 3" UNIVERSAL - TURBO BOOST LEAK TESTER - Tests any turbo with a 3" comp. inlet | eBay that should help you pressurize the system

Or he can build one for 15-20 bucks from home depot. Regardless if you think it is this or that a boost leak test should be done on any and every turbocharged car as often as possible.

 

[GSTurbo1]

Oh I know... speaking of, I ust got mine in from ebay today. Going to be checking mine today.

 

[Potenze]

Where is your boost source and BOV vac tapped?

 

[Gst to the max]

My bov, boost gauge and waste gate are all tapped into the intake

 

[GalantStroker]

Do you realize that fuel cut has NOTHING to do with the fuel system whatsoever. Fuel cut it caused when you flow a certain amount of air thru the maf sensor. This is caused by running higher boost OR a boost leak. This is common knowledge. Also the reason for this to set in in higher gears is because there is more load on the engine, the load on the engine last's longer in 2n'd gear than it does in 1st.

Maybe you call it something different, but when you're maxing out the injector duty cycle to the point where they can't flow any more i call that fuel cut.

I dont know what the OP is running for boost control since he didnt really specify, but what i do know is that when i first got my galant running it would spike peak boost before it was supposed to in the RPM band on account of the fact that it's a 2.4 and would display the exact symptoms he's talking about. In my case it was in the tune because that was with the stock ecu and stock boost settings, because once i switched over to the dsmlink ecu i didn't have the problem any longer, but the turbo and injectors were still stock.

All i was saying before is a little bit of extra information about his supporting mods would be nice before everyone just assumes it's a boost leak, because i saw someone say "well what if the coupler's popping off and then on" or something to that effect.. that definitely would cause a boost leak, , but, he probably wouldn't even see boost and the results certainly wouldn't be consistent. The reason why i'm saying this is odd is because yes, engine load is more in second gear, but, if anything it seems odd that there's less boost when there's more load on the engine, but pressure is pressure, so if 11 psi was enough to pop a leak somewhere (even assuming it went away after he shifted, wouldn't he also have the problem at 15 psi? correct me if i'm wrong but usually third and fourth gear pulls are where peak boost is made, are they not?

 

[bryanwheat]

Maybe you call it something different, but when you're maxing out the injector duty cycle to the point where they can't flow any more i call that fuel cut.

I dont know what the OP is running for boost control since he didnt really specify, but what i do know is that when i first got my galant running it would spike peak boost before it was supposed to in the RPM band on account of the fact that it's a 2.4 and would display the exact symptoms he's talking about. In my case it was in the tune because that was with the stock ecu and stock boost settings, because once i switched over to the dsmlink ecu i didn't have the problem any longer, but the turbo and injectors were still stock.

That isn't commonly referred to fuel cut. That is just overflowing the injectors which will lead to a lean condition. It won't violently make the car jerk and feel like you hit a wall.