Lumpy idle and power loss while accelerating

[frankozz]

New DSM new problems.... Haha Here we go.

Today I put the new suspension setup on my car. It looks sexy After I was done I wanted to take it out for a spin. Well as soon as I started the car it made this weird noise... Idle was steady under 1k, but it sounded like I had aftermarket cams... Really lumpy. I was like WTF? Then I took it out and the car doesn't pull as hard as it used to. It sounds really crappy too... The best I can describe it is like this. Before it used to make this sound. Vroooooooooom psssht Now it sounds like this Vrooooompummpummpummpumm...
Any ideas? suggestions?

 

[SkylinesSuck]

You probably popped off an intercooler pipe.

 

[frankozz]

No. That's not it. All my intercooler piping is tight.

 

[DSM4me44]

What did you do before this started?

Either you did something while installing your new suspension and haven't mentioned it to us

or

Something went bad, in which case I would suspect you have a check engine light on.

 

[SkylinesSuck]

Well maybe you accidentally sliced a coupler? Don't just do a visual check of the clamps. Make a boost leak tester (takes 10 minutes) and check it that way. There are very few things you could have screwed up on you engine changing your suspension unless it's some strange DSM thing I don't know about.

Check all the electrical connections around the suspension area also. Maybe if you popped the plug off the MAF or coolant temp sensor it could do something similar.

 

[frankozz]

Well the only thing I did under the hood was that I put a vacuum line straight from the J pipe and into the wastegate because apparently the previous owner had an AEM boost control solenoid conected to the stock BCS and vacuum lines running to the j pipe, wastegate and boost gauge. I removed everything and I just put a vacuum line from the j pipe to the wastegate... That shouldn't affect anything should it?

 

[SkylinesSuck]

I'd look real hard in that area for some kind of leak. I'm telling ya, make yourself a boost leak tester. 10 minutes, and even if that's not the problem, I'll bet you find some other small leaks, and it's great peace of mind knowing you have no leaks. I bet you'll find your problem like that though.

 

[frankozz]

Here's a video I made that shows the problem I'm having.

talon problems Video by ****[[franciskith0o]]**** - MySpace Video

 

[1996dsm]

I dont see a video link.

 

[bling5tatus]

sounds like a miss to me. I'd do a compression check.... and get a logger, that'll solve any "no cel lamp" problems he may have created for you by taking the bulb out....

 

[beating4g63s]

remove the cluster and remove the bulb to either your door light or your brake light, and put it for your cel, or go to autozone and pick up another bulb and see if your throwing any cel, second put back what ever that aem boost thing was like it was before the suspension, eliminate those two things before going any further, you'll be highly mad if all you had to do was reconnect that aem thing.

 

[dgdsm]

Have you opened up your ECU? If it's not the instrument cluster bulb, a non-functioning CEL at startup could be a sign of a badly damaged ECU.

 

[frankozz]

Just to add, nevermind about the check engine light... It does light up when the key is on the on position, then when I start the car it turns off....

 

[Calan]

Well the only thing I did under the hood was that I put a vacuum line straight from the J pipe and into the wastegate because apparently the previous owner had an AEM boost control solenoid conected to the stock BCS and vacuum lines running to the j pipe, wastegate and boost gauge. I removed everything and I just put a vacuum line from the j pipe to the wastegate... That shouldn't affect anything should it?

Sure it could.

As for the power loss... however the boost control was set up and working before, you've probably changed the boost level now, which in turn could be (and probably is) affecting what the ECU is doing in open loop. If you've lowered your boost, that alone accounts for "less power" at WOT. What level of boost are you running now, and what was it before? You do have a good aftermarket boost gauge, right?

The idle issue could be several things, including something related to what you did when you reconfigured your boost controller, like leaving a vac line off and causing a boost/vac leak. Start with the basics, and systematically eliminate potential causes. First things first... double check all the lines that you may have changed, look for something that you accidently unplugged or hooked up wrong, and like SkylinesSuck mentioned up there ^ a couple of times ...DO A PROPER BOOST LEAK TEST.

Play the odds here....although possible, it's highly unlikely that something just randomly "failed" on your car, at exactly the same time you were reconfiguring the vaccum lines/boost controller and installing a new suspension

 

[dsm'sROCK]

your not fiering all cylinders

 

[Kstallard34]

Make sure all your injector's are plugged in and clips are in. You could also pull a plug at a time while its running and find if your missing in a certain cyl.

 

[frankozz]

I pulled each spark plug wire and the car idled different when I pulled each cable out. I could also see it spark.

 

[DSM4me44]

Check the order of your spark plug wires. I had something similar sounding. That was my problem.

 

[SkylinesSuck]

Yeah, that sounds like a hard miss. I don't think it's a boost leak now. You said you have spark to every cylinder, and pulling the spark plug wires changed the idle with every plug wire? If your idle doesn't stay the same when you disconnectied one plug wire, that would indicate its an intermittent miss on all of the cylinders. Did you bump your distributor/coil packs (not sure what you guys have) and cam angle sensors?

 

[bling5tatus]

Sure it could.

As for the power loss... however the boost control was set up and working before, you've probably changed the boost level now, which in turn could be (and probably is) affecting what the ECU is doing in open loop. If you've lowered your boost, that alone accounts for "less power" at WOT. What level of boost are you running now, and what was it before? You do have a good aftermarket boost gauge, right?

The idle issue could be several things, including something related to what you did when you reconfigured your boost controller, like leaving a vac line off and causing a boost/vac leak. Start with the basics, and systematically eliminate potential causes. First things first... double check all the lines that you may have changed, look for something that you accidently unplugged or hooked up wrong, and like SkylinesSuck mentioned up there ^ a couple of times ...DO A PROPER BOOST LEAK TEST.

Play the odds here....although possible, it's highly unlikely that something just randomly "failed" on your car, at exactly the same time you were reconfiguring the vaccum lines/boost controller and installing a new suspension

It's good you're trying to help, but you really should try to help by first understanding exactly what the problem is. The power loss he is having is a direct result of the cylinder missing (for whatever reason)... and you can hear this at idle. This has nothing to do with what his boost level is set at (short of it maybe having gone so high that it damaged one of the cylinders) because the wastegate isn't used when there is no load on the motor (because very little to no boost is even built). One vacuum line being disconnected doesn't generally create such an air fuel ratio issue at idle as to make the motor sound like it's missing.

I would seriously compression test the car.... and verify the plug wire order as said before.

 

[frankozz]

I think I found my problem... Boost leak anyone?

You must be logged in to view this image or video.

 

[SkylinesSuck]

That's an intercooler pipe?

I don't think that by itself would cause that hard of a miss though. Now if you've been driving like that for a while and it's been running rich since the MAF is metering all that air (and adding fuel for it) but that air is escaping, that would foul your plugs. Tape it up real quick and change the plugs. See if that fixes it at idle. What do the plugs look like?

 

[frankozz]

Yeah, that's my intercooler pipe that exits the right side of the intercooler... It has a huge crack in it... So you are saying that a crack in the piping wouldn't cause the idle issue I'm having? I know that's the explanation for the power loss... And possibly the missfire I get when I step on the gas....

 

[frankozz]

Well I just wanted to let you guys know I found what the problem was. I went over to NAPA and got the NGK spark plugs and that solved my issues My car runs like a champ now. I still have to replace that intercooler pipe...

 

[Calan]

Well I just wanted to let you guys know I found what the problem was. I went over to NAPA and got the NGK spark plugs and that solved my issues My car runs like a champ now. I still have to replace that intercooler pipe...

Glad it's better... and it "run's like a champ" even with that gaping crack in the IC pipe?

It's good you're trying to help, but you really should try to help by first understanding exactly what the problem is. The power loss he is having is a direct result of the cylinder missing (for whatever reason)... and you can hear this at idle.

I couldn't hear the video link when I made that post, but if a problem appears after work is done, it's always a good bet that something was done to cause the problem. Either that or by fixing one or more problems, others become more obvious.

The point I was trying to make is that assuming a brainfart and double-checking your work is the easiest and most logical first step in isolating a "new" problem, especially in a case like the OP's.

...One vacuum line being disconnected doesn't generally create such an air fuel ratio issue at idle as to make the motor sound like it's missing.

Well...maybe not missing. But with my car in a stock PCV configuration and GM-MAF in blow through (i.e. vac leak) , I was only logging .12 for AirFlowPerRev at one point, which was definitely noticable. (I never did get much above .21, but most of this was due to injector deadtimes being out of whack).

I would seriously compression test the car.... and verify the plug wire order as said before.

Always a good idea, along with a BLT and leak-down test.

I wonder how the OP's BLT looks with that IC pipe like it is? Unless it is just a weird looking surface crack or has (hopefully) been fixed by now