Car bogging down/stalling out/loss in performence

[MSJHWT]

Okay, I just can't win with my Grand-Am.
Probably going in for service Wednesday, but until then any advice would be appreciated.
Car will run REALLY lean now when I floor it, like one red dot on the Air/Fuel meter lean. It will go from 2k rmps to 4500 back down to 1000 when I floor it. When just cruising, it will go from like 2500 to 3000 to 1500 with constant pressure on the pedal.
When I floor it, the car backfires.
Car stalls out randomly when cruising. In addition, headlights dim/interior lights dim when cruising, no radio on, if Air Conditioning is on it will get hot for a sec then get cold again.
When driving normally A/F gauge no longer bounces from lean to rich, it goes from lean to the last stoich.
Also know I'm running bad performence wise, as a comparison, my best run at the track N/A was a 15.082, but on Friday the best N/A I could pull was a 15.758, on same conditions with a lighter car (by almost 400lbs).
So it's been getting progressively worse, at first it wouldn't bog down at all and I just noticed it at the track, then it started bogging now and then, now it bogs almost all the time.

What I think it is: Dirty Fuel Filter, Bad Injectors, loose vaccume hose....

Anyone have any Ideas/Suggestions? Should a fuel filter need to be cleaned by 32000 miles? (running headers/intake/exhaust)? Or do fuel injectors go bad by then?

[speak03]

it definetly sounds like a vacuum problem, I would check all your hoses and probably have it looked at.

[MSJHWT]

Checked all my hoses, didn't work, getting really annoyed, it was bad when it was just bogging down, but I stalled out 32!!!! times on the 12 mile trip from home. Not only is it annoying, it's also dangerous to suddenly have no power stearing/brakes and no accelaration
Getting it looked at tomorrow.

[MSJHWT]

Question: If I didn't fully screw a spark plug all the way in might it do this? #6 was giving me problems and i thought I got it all the way in, it might not be all the way in, though.

[Vintalage]

Man, that sucks. I've got the gasket leak problem so I need to get that looked at. I just don't want to take it into the dealership at this time given the condition the interior is in. No center console plus missing trim pieces might not look to good in the service assistant's eyes. :/

It doesn't sound like it's a spark plug issue unless the engine is running rough all the time. Is it misfiring?

[Germ]

if you have been running lean for awhile you probably have some fouled plugs that are giving you these issues.

i would suggest 6 new plugs and see what happens.

i had something very similar happen to me last year

[MSJHWT]

Man, that sucks. I've got the gasket leak problem so I need to get that looked at. I just don't want to take it into the dealership at this time given the condition the interior is in. No center console plus missing trim pieces might not look to good in the service assistant's eyes. :/

It doesn't sound like it's a spark plug issue unless the engine is running rough all the time. Is it misfiring?

hehe I did that, took it in when I was painting my interior....just told them what I was doing,
It'll run rough right when I start her up, and then she'll be fine for a while, then stall out, then have issues shifting into drive, she likes to stall going from park to drive. Not really getting any misfires.

if you have been running lean for awhile you probably have some fouled plugs that are giving you these issues.

i would suggest 6 new plugs and see what happens.

i had something very similar happen to me last year

I'll change the plugs out tonight, if it dosen't fix itself, then it goes into the dealership

[Germ]

have you been shooting the N2O at all?

do you have any mods done to help fuel flow? like an AFPR? if not, i would suggest one. cause i bet that your running way lean, no matter what your A/F gauge is telling you. that thing is just an estimate and is not close to be accurate, especially if you spliced it off of your stock O2 sensor.

with all of that free flowing air flow track you have (dr. S intake, exhaust, headers) i would almost guarantee your running lean.

look into an AFPR while your at it

[MSJHWT]

Shot the N20 twice, I don't have an AFPR, I'll look into getting one of pfyc.com.

Thanks for the info

[speak03]

has it been acting up before the Nitrous install? because I had the same problem and it was because my T fitting and vacuum line were too big in inner diameter. i went to advance auto and bought small t fitting and OEM size vacuum hose and it's fine.

[MSJHWT]

It didn't act up before the nitrous install....but I did drive 12 hours (and 700 miles) home right after the nitrous install. But this all did happen shortly after the nitrous install/me changing spark plugs + wires. I just got some hose clamps to try to make sure everything is clamped off right, let's hope
If I go and get some OEM hoses, do you know what size it is? Should I just tell them it's a Grand-Am and they should know? Right now I actually want to hold off bringing it into the dealership as much as possible ---- don't want to have to uninstall the nitrous and I don't want to bring it in with the nitrous on it.

[speak03]

The two hoses they gave you are fine, it's the hose that goes from the T fitting to the top of the FPR, I dont remember the size but you could unplug the original Vacuum hose and bring it in. I do know there are 3 different sizes, and you'll need to buy the end fittings too. I'll go take some pictures and show you.

[MSJHWT]

Hm My nitrous system is setup differently, there isn't a T fitting, the stock hose that went to the T fitting is sealed off, and there is a new hose on the FPR....this is probably my problem though if this is the same issue you were having and my FPR is setup diffently, I'll go get a T-Fitting tomorrow and some hose for it. Advanced Auto should carry the T-fitting and all right? They're closed now, but tomorrow I'll get all this stuff.
Thanks for all the pics and info, they've been very informative to me!

Did you powdercoat or paint your manifold? It looks really good!

[MSJHWT]

Nother question for you, did yours work OK for a while then break, or was it a constant issue? Just don't know why it would be fine for the ride home (thank god it was, though) and then break. Also, it does better after it's been sitting a while and I start it up. After sitting overnight and me trying to tighten the vaccume lines I drove it for 2 miles before it even studdered a little bit, then was back up to its old habits, did this happen to you?

[speak03]

ya, for some reason the hoses and T- fittings that came with it just did not work, so as a last ditched effort I bought new hoses and T fitting and I havent had a problem yet! Advanced should most definetly have all of it. make sure that the two hoses are the same diameter, and you'll need to buy 2 vacuum connector ends, one for the top of the FPR and one for the end of the T fitting(should look OEM). let me know if you have any other questions.

[MSJHWT]

Okay, so plan for tomorrow, got new plugs, going to switch them tomorrow (too tierd to do it right now), buy new hoses and a T fitting and actually do this first cuz its a lot easier than the plugs
thanks
Justin

[speak03]

mine was fine for a whole week and then started acting up! why? I have no idea, but it got so bad that It wouldn't even start one time. so at the gas station i unhooked the t fitting and put the original vacuum hose back on the FPR, and it started right up, thats when I knew it was a vacuum problem

[MSJHWT]

hmmm, *gives me an idea*, lets go hook up the stock vaccume hose!
That sounds just like me, worked for a week!

[speak03]

i would say go hook the stock one up and see if it's fine. I'm an idiot for not suggesting that to begin with!

[MSJHWT]

Did it, drove 10 miles and didn't notice any issues with it! So think changing the hoses will be the step I take tomorrow, then test it a little further!

Thanks!!!