No idle after LICP install

[Galaxy]

I made a licp out of exhaust tubing,put it in yesterday,triple checked the couplers for leaks (which shouldn't matter until it sees boost) and my car won't idle,It will start and go to about 2000 rpms and slowly drop back to about 800 and then just shake and fight to run then it dies.

Should I have reset the ecu? I'm doing that now before I put the stock rubber LICP back on just to see if thats where my problem is.

I can do a turbo motor swap,clutch,timing belt,all with no problem but I go to change spark plugs or something easy and I screw it up,haha.

 

[sirsol66]

When the idle surges like that, its usually the sign of a vacuum leak. Go over the entire car and make sure vac lines are good and quadruple check all of the connections. Is it possible some of the couplers you used have tears? You can use a small spray bottle with 50/50 mix of water and soap to find any leaky connections as it will bubble or hiss when you spray the leak with the mixture. Good luck!

 

[-TunedDSM-]

Most likely a boost/vacuum leak. Did you remember to plug in the MAF and vac lines to the intake when you put it all together?

 

[Galaxy]

MAF was never unplugged but I wiggled it in case..no vac lines to the intale,running a breather.

I'll go check those couplers...its gotta be a massive leak

 

[Galaxy]

no leaks,swapped back to stock rubber pipe,car still revs to 2000 and then slowly drops to its death.

 

[TrevorS]

no leaks,swapped back to stock rubber pipe,car still revs to 2000 and then slowly drops to its death.

Inspection is hit or miss. As suggested above, do a Boost Leak Test. That'll identify both vacuum and boost leaks.

 

[Galaxy]

Inspection may be hit or miss but swapping out the pipe for the stock one it ran fine with yesterday,would be a great start if that was the pipe that was suspect.

I really touched nothing else when removing that pipe.Even removed it and re-installed it to fab up the pipe and it was fine afterward.

I don't have a boost leak tester that works and cannot find a COMPLETE how to on a boost leak test.All Of them I've ever read say nothing about rotating the crank to TDC but someone mentioned that a few weeks ago.

I have no idea how to boost leak test other than cap the turbo and pressurize the system...this shows nothing on my boost gauge and air just hisses everywhere,pretty useless to me.

If anyone knows how to do that or can link me to a COMPLETE how to,that would maybe be useful.

 

[Galaxy]

Ok,found that it's 30* ATDC to do a boost leak test.

It has to be something I bumped like put a hole in a line somewhere and I'm just not thinking about it or checking everywhere.

I'll try to boost/vac leak test it when its not raining.

 

[crimsondragon]

When the idle surges like that, its usually the sign of a vacuum leak. Go over the entire car and make sure vac lines are good and quadruple check all of the connections. Is it possible some of the couplers you used have tears? You can use a small spray bottle with 50/50 mix of water and soap to find any leaky connections as it will bubble or hiss when you spray the leak with the mixture. Good luck!

That's a pretty horrible idea. Soap/water is good for detecting boost leaks but vac leaks? No. Use starter fluid. Any change in engine revs will indicate leak.

 

[No_Skillz]

Ok,found that it's 30* ATDC to do a boost leak test.

It has to be something I bumped like put a hole in a line somewhere and I'm just not thinking about it or checking everywhere.

I'll try to boost/vac leak test it when its not raining.

The TDC concern is more for people running big and/or aggressive cams. It's basically to make sure all intake valves are closed or there is no valve overlap. Otherwise, you may lose pressure via the piston rings into the crank case or you might not build any pressure at all if there is overlap.

You can safely do a BLT without worrying about it at all. If you suspect blowby losses or build no pressure at all, you can give the ignition a quick flick to crank past that particular valve position.

 

[Galaxy]

I can do a turbo motor swap,clutch,timing belt,all with no problem but I go to change spark plugs or something easy and I screw it up,haha.

Like I said,something simple and I screw it up.I had disconnected the fat vacuum line to the brake booster to get a look at the clutch master cylinder and completely forgot.I saw the shiny ass nipple on the manifold shining in the sun this morning and felt like a moron.

On a side note the LICP I made does not work,It boosts to about 10 psi pretty slow like there's a leak but I can't get those hose clamps any tighter.Would the larger diameter of the pipe make that much of a difference in the way it spools?

 

[TrevorS]

The TDC concern is more for people running big and/or aggressive cams. It's basically to make sure all intake valves are closed or there is no valve overlap. Otherwise, you may lose pressure via the piston rings into the crank case or you might not build any pressure at all if there is overlap.

You can safely do a BLT without worrying about it at all. If you suspect blowby losses or build no pressure at all, you can give the ignition a quick flick to crank past that particular valve position.

Anybody who does this -- beware of accidentally starting the engine, major damage could happen fast if setup for a BLT. Safest if you disconnect the plugs or injectors first.

 

[TrevorS]

Like I said,something simple and I screw it up.I had disconnected the fat vacuum line to the brake booster to get a look at the clutch master cylinder and completely forgot.I saw the shiny ass nipple on the manifold shining in the sun this morning and felt like a moron.

On a side note the LICP I made does not work,It boosts to about 10 psi pretty slow like there's a leak but I can't get those hose clamps any tighter.Would the larger diameter of the pipe make that much of a difference in the way it spools?

Not for any reasonable diameter pipe. Once again, sounds like a BLT opportunity !

 

[Galaxy]

I'll have to get a tester made up this week that actually works and check it.