My car is doing funny things

[Cal-Gal]

I have a 2000 Pontiac Sunfire GT (5-speed manual transmission) for about 4 years now. Its been a pretty good car for my purposes, and I've maintained it well.

Lately though I've been having issues with my car. There seems to be a problem with the engine not getting enough fuel - especially when I'm shifting up through 2nd and 3rd gear, around 2500 RPM. Its as if the car is lagging and lurching a little. I have to hammer the gas pedal to get it to quit lurching. I'm not in too high of a gear though...its just as if it doesn't really want to go.

I'm thinking this is a problem somewhere in the fuel system - maybe the fuel filter or fuel pump??

Does anyone have any ideas about what the problem could be....and more importantly how much its going to cost me to fix it? I just hate taking my car in for repairs, because I always feel I'm getting hosed, and I don't know enough about cars to know if I'm being fed a bunch of lies by repairmen.

Thanks in advance for any help!

[TheyCallMeBruce]

Did your check engine light come on? You could probably bring it in and have them do a diagnostic on it, or visit a Sunfire forum and see if you can look up the engine code to see what exactly may be wrong. Truthfully, there can be a dozen number of things wrong, anything from loss of cylinder compression to spark plugs.

[Fozzie_DeBear]

I agree with Bruce there are so many things it could be...I had a similar problem when a mass airflow sensor busted and then sent the engine computer bad data and screwed up the fuel air mix...a diagnostic is the only way to know

[arsenal]

I am with TCMB. See if you can find a sunfire forum, and ask them there, or search the forums to see if you can find someone that has had the same problem before.

I think your car is new enough, that you could buy an ECU reader from Canadian Tire. It should be able to determine what if anything is wrong with your vehicle. I think they are about $50 though.

If you have a friend that knows how to read vehicle error codes, that could be a cheap starting point at least.

And if you car has a MAF (mass air flow), that would be the first place to check. Seems to be an issue with many vehicles, and RPM's hesitating.

[FlamesKickAss]

jspeed.ca is a forum for j-body cars (what sunfires are) they might be able to help

[Burninator]

And here I thought your car was telling jokes or something...

[Bertuzzied]

Sorry a bit off topic but my friends old Nissan 240SX did the funniest thing ever.

He installed a new cd deck but somehow screwed up the wiring. Whenever he made a left turn signal his front headlights would pop up. hahahahahaha.

[burn_baby_burn]

I would change the fuel filter first. That would be the easiest and cheapest thing to do. If your still having problems with the new filter I would definately bring it in to get diagnosed.

[NuclearFart]

It could be that you just need a tune-up. My civic was doing the same thing, but then after a quick tune-up it was working fine again.
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ATIVAN REHAB DICUSSION

[NuclearFart]

Originally Posted by fotze

DO you really think its safe to be diagnosing car troubles over the internet? Maybe leave that up to the professionals.

hehe touche. This is all strictly anecdotal, so reader beware....or at the very least dont sue me if wrong.
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HIGH OFF DARVOCET

[4X4]

STOP!

Before you buy ECU readers and whatnot, go to Auto Value and have them run the diagnostic test (free!). If there's no check engine light, chances are that they won't be able to tell you much, but it's better than paying a mechanic for a diag. The ECU reader is the same thing. You'll save the $50.


That failing, and assuming that you have some mechanical wherewithall, it sounds to me like either a TPS (throttle positioning sensor), exhaust (probably a plugged calatyic converter), or a fuel pump or filter problem.

Other possibilities include: O2 sensor, intake air sensor, or just plain old crappy gas. Stop filling up on the reserve.

The TPS will be the cheapest. Probably ~$100 and easily installed yourself (with a little help from a Haynes manual (~$20)).

The exhaust will be next cheapest at around ~$200 to take out the catalytic converter and pop in a resonator, assuming you don't have a second O2 sensor after the catalytic converter, in which case you'll have to replace the catalytic converter and those run anywhere from $300-$600 plus installation (no, you can't do this in the garage).

FUel pumps vary. sometimes they're inside the gas tank and that ups the cost of the part and the cost of installation. I won't even guess at how much it'll be for a Grand Prix, but I'll tell you that the part for my GMC Jimmy is $600 and the installation is 2.5 hours at a shop rate of $100/hour, for a total of $850 PLUS MOFUGGIN TAX.

I hope your problem is the TPS... }

[Winsor_Pilates]

The fuel pump on my Sunfire went bad soon after I bought it and it cost about 800-1000 to replace. It started like a stutter that would happen when I was sitting idle. Then after a while the car would stall after the stuttering.

Hope this isn't your problem since it was pretty expensive. The good news is I havn't had any issues since and that was about 6-7 years ago.

[4X4]

I just re-read your post and am going to bet that it's exhaust related. I'm not going to bet money, however... Just pride. Really really sounds like the CC. Get 'er chopped out and stick in a resonator. $250 tops.

If there's any stalling, though, describe it. If it's only power loss and sputtering during accelleration, it really sounds exhaust related.

[Cal-Gal]

The car has never stalled - always idles just a shade under 1000 RPM while in neutral. It pulls just fine in the higher RPMs, it just seems to be mis-firing between 2 and 3 thousand RPM. The check engine light has never come on.

Anyway, like I said when I'm moving through the gears I have to push alot more fuel to the engine than usual to get it to rev higher, and avoid the lurching/shuddering/mis-firing. On the highway, it doesn't pull well in 5th gear anymore - but it always used to.

I just had the brakes done for about $500, so I'm frustrated at the prospect of having to drop another huge wad of cash on my car.

I really appreciate everyone's suggestions so far.

[CRXguy]

It could be your catalytic converter. A clogged cat could cause the car to hesitate. It's not too expensive, and I'd recommend Carline to do the work. If you have a MAF(mass airflow sensor), it might be due for a cleaning. Just buy some electrical spray at NAPA, spray it down and put it in a ziploc bag and shake it around. Then let it dry thoroughly and re-install.

[4X4]

Have you noticed a different sound to the engine? Have you noticed (almost imperceptible) new vibrations when accelerating or decelerating rapidly? A very deep noise like Barry White singing in the background?
If yes, definitely exhaust.

I vouch for Calgary Muffler. They're across from Chinook in the Johnny Rocket parking lot.
But before you take your car anywhere, call a bunch of places and describe the problem and ask for estimates. You'll be able to narrow it down better.

[Cal-Gal]

I can't say I've heard Barry White in my car . The engine sounds OK, and there is no vibrating when decelerating - just the lagging when accelerating.

Is there any use in going to a place like Mr. Lube and getting the fuel system cleaned first? I was thinking of starting there...then take it to a repair place if that doesn't solve the problem.

[ken0042]

Originally Posted by Cal-Gal

I just had the brakes done for about $500, so I'm frustrated at the prospect of having to drop another huge wad of cash on my car.

Originally Posted by Cal-Gal

Is there any use in going to a place like Mr. Lube and getting the fuel system cleaned first? I was thinking of starting there...then take it to a repair place if that doesn't solve the problem.

I think you just answered your own question. You are tired of spending money on this car; why pay to have a proceedure done that may or may not do anything- let alone have that work done by somebody who likely isn't qualified to diagnose any sort of problem.

Stop into the dealer and ask if they have heard of this. Check out a couple of other mechanics- do a lot of this in person as a mechanic is more likely to be able to point you in the right direction if he can have a quick look at the car.

[4X4]

I'm telling you, it's most likely exhaust related. If you don't want to risk it, take it to somewhere good like South Pro Automotive and have it diagnosed. Just say no to the 16 y/o that works at Mr. Lube.

[Cal-Gal]

Gotcha....thanks for the advice.

I'll start calling places tomorrow including South Pro, Carline, and Calgary Muffler.

I appreciate the help, and I'll let you know what the outcome is.