power loss at low RPMs, possible fuel filter?

[Psychobroker]

I ran a search, but didn't really know what to look for, so I decided to post about something that happened last night.First and foremost, the only engine mods I've performed so far are an AEM CAI, MFlow exhaist, and ground wires. AEM pulley kit hasn't been installed yet...I was driving home from a friend's house, when I seemed to lose power/throttle response when the clutch engaged. It was more noticable when launching than in any other gear. Basically, I would launch like normal (rev to 3k while letting off the clutch), clutch would engage, but the RPM's would then dip (not close to stalling), and I would try to step on it to compensate, but there was very little improvedment until the engine revved over 3,500 RPMs. Even then it was sluggish. The throttle should have been wide open as I was flooring it.This has happened twice now...I thought my mind was messin' with me the first time until it happened last night. I pulled over to the side of the road, popped the hood, and heard a "clicking" sound coming from near the MAF (I think). So, I wiggled it a bit, along with the intake, and it stopped. I haven't had this problem since, but what could it be? I still don't see how this could be the intake/MAF, but I'm clueless. Thanks in advance for anyone's help.

[AKLGT]

the clicking is from the vsv valve... it's normal. could also be from vibration in the engine compartment too. i had to put some rubber stripping around it so it didn't do that but it still does. the loss of power when you shift... that kinda sounds like a clutch slipping. if you put your foot on the gas after you change gears and the rpms go up, but you don't really move, i'm told is clutch slippage. i get that occassionally too, but not all the time.you should take it in for sure!

[joatmon]

his problem was stepping on the gas caused RPMs to drop. If the clutch was slipping the engine would race---------Maybe check to make sure your vacuum lines are still hooked up

[Psychobroker]

Yep, the RPM's would drop...I just finished driving around a bit and no problems so far. Excuse my ignorance, but which one is the VSV valve?

[AKLGT]

ah, gotcha. i read that wrong... the opposite. oops.

[DavidPIL]

Hiya...I must first state that I'm really not that knowledgable when it comes to cars but if I remember correctly, a long time ago something similar happened to me when I got a bad tank of gas. I could idle ok but when I gave it any gas at all, the engine would try to die. Now, I know you said you can rev a little then when you let off the clutch it does this but my circumstance was with an automatic but the issue does seem similar.There have been several people have fuel filter issues with their Vibes. My gas problem resulted in the need to have the tank completely drained and cleaned. Also ran into Fuel Filter issues, cuz that's usually where it clogs first. After my bad gas incident, I did have a few other times when I needed to have the fuel filter changed. Each time if reminded me of the bad gas incident. Maybe others who have had the fuel filter clog on their Vibes cold weigh in to let us all know if this was a similar result. I wouldn't be able to assume it was anything in particular but this might be the problem. Anyone else have thoughts?Dave

[Psychobroker]

*BUMP*This problem has sprung up again, so I called a couple different techs, one being the guy that installed my intake and exhaust, and the other being my Pontiac dealer service dept. guy. Mike @ Pontiac says it's a fuel filter that needs changing @ every 15,000 miles, however, nothing in our owner manuals even reference the fuel filter, let alone the scheduled maintenance log. After searching other threads, it turns out this filter is located inside our fuel tanks along w/ the pump, so like hell I'd try to replace this myself.My a/m guy thinks it's the spark plugs, even after I pointed out that they're iridium tipped and SHOULD last ~100k miles. Even so, he doesn't think it's the fuel filter. However, most of his experience comes from various Nissans and MR2's/Supras, NOT the 2zz engine.So, has anyone else had a similar problem, taken it to the dealer, and found it was the fuel filter? It sounds a lot like Dave's problem, so before I hand over my car for a diagnosis, I hope others could chime in with advise.Thank you in advance!-Christian

[joatmon]

I suppose it could be the fuel filter, but you said that there was clicking sound by the intake, you wiggled it and it got better, then after some time (a week or two?) the problem came back. I would think that if it was a fuel filter problem, no amount of wiggling by the MAF would clear it up, and when I have had fuel filters get clogged, they stayed clogged and didn;t go intermittent on me. I guess it could happen, but I wouldn't expect that.

[Psychobroker]

Well, the VSV noise and my wiggling of things (lol) could all have been coincidental. What the hell could clog a fuel filter so quickly? I've got just under 17k miles on my GT.

[MadBill]

I wonder if maybe joatman inadvertently nailed it. He mentioned the MAF. Didn't someone have a prob with an SC install because the MAF was defective and some "limp home" mode kicked in, limiting the RPM to ~ 3,000? Maybe there's an intermittent wiring or MAF sensor defect? (Although it should have set a code)

[AKLGT]

yes, i remember that thread. christian, you may want to have them check out your MAF sensor!

[Psychobroker]

Well, my RPM's are definitely not limited. The engine will rev all the way to red line (I really don't want to push it though), but it's just sluggish between 1k-4k. it's almost like it hits a pre-lift at 4k all the way to 6200, lift, then red-line. To put it simply, it feels like I've lost some low end torque. I can see where it would want to stall out in an auto, but because the GT's a stick, I've been compensating.

[joatmon]

How about a vacuum leak? Maybe at low engine speeds a loose , broken or disconnected vacuum line is significant, but at high RPMs the GT engine sucks atmosphere like a black hole and the small leak doesn't matter.

[Pablo1669]

Quote, originally posted by silverawd26 » maybe they forgot to place that cap on the nipple near the Throttle Body. Def check to see if there is a black cap on that one location, it is suppose to be capped off after you install the CAI.This is the first thing I checked when I got my car back from getting a new engine. I had no faith in my dealership to notice that cap, They did, and they replaced it much to my surprise.

[goodvibe]

I would try cleaning the MAF and then resetting the ecu. Oil from the filter can foul these pretty easily. If your running slightly lean it may correlate to your problem. The fuel curve on these cars is such that it runs lean at low rpm (perhaps too lean in your case) and rich at high rpm.

[Psychobroker]

Quote »Lancer had the same problem, no torque and loss of power and once her reset the ECU.... He was back in business..............Hmm, interesting, but would this be an intermittent problem? On the way to the Pontiac service dept. this morning it was running just fine...go figure. It makes me think it's a loose connection of some sort somewhere. If a fuel filter is fouled/clogged, wouldn't it stay that way?Anyway, they have my Vibe and I hope they'll find the problem. Thank you everyone for all the suggestions. If you think of anything else, please do post it here Argh, this is frustrating.

[hman33]

how do you go about resetting the ecu? just curious in case i have to do it sometime.

[goodvibe]

I've done it by pulling the EFI fuses. I think you only need to pull one of the two but I just yank em both.

[Psychobroker]

Quote »Well, first of all you quoted the wrong person. I am the one who gave you the information to reset your ECU.Erm, ok, I didn't think I said I was quoting anyone in particular, just the last person to mention "reset your ECU". I apologize if I unjustly awarded your praise to someone else. Quote »Anyways, your welcome for the information and I am glad you are back on your feet.Quote »Thank you everyone for all the suggestions."Everyone" includes you too, silverawd. But if it makes you feel better..THANK YOU SILVERAWD26, I DON'T KNOW WHAT I WOULD HAVE DONE WITHOUT YOU.Even so, Pontiac found nothing wrong and it's started up again, so I'll reset the ECU after work. EDIT: I thought I had quoted you...isn't this yours?Quote »Lancer had the same problem, no torque and loss of power and once her reset the ECU.... He was back in business..............???