ok well first off the car is a 98 Z24 5spd w/ about 121K on it. now heres the problem.... everytime it gets just a lil warm outside my car acts up. i live 10 miles from work and cant even make it home w/ out pulling over shutting off the car for a min or two then starting it back up and get the rest of the way home. it acts like it starving for something air or fuel i dont know. it never completely stalls out but close. its not overheating., i just replaced the water pump, timing chain, and thermostat couple of months ago. Since this problem has started i've replaced these sensors: IAT, both exhuast O2 sensors, coil pack, spark plugs, TPS, MAP. and i've ran a bottle of "fuel injection cleaner" . it cant think of anything else to really replace.... Due to this problem i'm replacing the entire motor in about 2 months.... but this is my daily driver i need it to run till i get the new motor together. Can anyone please help me... PLEASE... i cant take this anymore.... and to top it all off my bday was last week.... guess what i got.... my car broken into! ive not had the best luck w/ this car lately. any advice?????????

thanks for reading

Jason
PS the only performance MODS are intake, high flow cat, cat back exhuast, high rev's O2 simulator, and car customs upper mount

Can't promise anything but try this. Unbolt the Catalytic converter and remove it. See if that helps. It's going to sound rough but I have had a number of cars do this once they got over 100k on the engine. (Especially if you live below the Mason/Dixion line. Something about the heat and humidity really kills these things.) The symptons that you are describing are classic cat issues (the gasses can't pass through the cat and backup into the enging. This in turn starves the engine for air. Creating the stalling that you are having.). Keep us Posted.



"You must realize one day you are going to die. Until then you are useless to us."-Tyler Durden

fuel filter? ever? lol

fuel pump or fuel pressure regulator? let us know what find. good luck.

Fuel filter, possibly fuel pump, umm not the cat he has a high flo cat which is pretty much no cat,
try the fuel filter first and call me in the morning...i bet that does it

well first off, thanks alot for all your input ! and yes i fuel filter is new also.... thought off that already.
second...... i feel like a real a$$ right now. about 6 months ago i got a CEL, so i plugged in my trusty OBDII scan tool and came back w/ some code ( i forget exactly ) but it had something to w/ the post cat 02 sensor. first thing i thought of was that the sensor was bad. i tried to replace it but when the idiots welded my cat in they put a real nyce bead around the O2 sensor making it impossible to get it out, hense the reason i got the O2 simulator from high rev . but now that you said that about the CAT it makes complete sense now... and i feel stupid!! so i have off work tomorrow i'm going to get a new cat put in..... i'll let you all know how it turns out... thanks again!!!

Jason

dont just throw a new cat on, they aint that cheap, try what he said bout pullin it first. and to tell you the truth if your car dont run like ass (smoke and crap) id say dont worry bout replacing it, just knock out the innards, so long as you dont have full on emissions inspections. i know allot of pa requires em, but not sure bout york area

now that i read ur profile, im kinda doubting cat,unless you baught a defective one. it sounds like ur having a fuel delivery problem

ok well i went to the local shop yesterday.... talked to them for about an hour, told them everything.... they didnt think it was the CAT either.... so i have an appointment 8 am monday morning to have it hooked up to a computer to check EVERYTHING out.... especially my fuel system. so hopefully they will figure something out.... i'm hoping it'll be a cheap fix, but i kinda doubt it............. wish me luck and i'll keep you all posted
thanks
jason

ok so had the car hooked up today.... nothing really came back EXCEPT one thing. my car was running too cool. this is due to me putting a 180 thermostat in instead of the OE 195. the guy at the shop said he couldnt tell me 100% that the thermostat was the problem but he has seen it cause simaliar problems before. so i fugured what the hell ... i put a 195 in it.... ran it around, sat in traffic for awhile.... ran GREAT.... now its just OVERHEATING.... i cant win i swear. it didnt overheat completely .. it got to the line between 195 and 260..... and i could literally hear it boiling?!?!? wtf????

Jason

um check into a new EGR valve

or block off the EGR

here's another idea, u may need a new temperature SENSOR, not a temp sender, the Sensor, i think they are both beside the water outlet on the right side (lookin at motor from front of car) this has a yellow wire, and a brown wire coming from it

well turns out i just didnt have enough fluid in.... hense the slight over heating yesterday. but i filled it today, went to and from work.... and for the first time in god knows how long... it didnt spit or sputter like crazy, or overheat. its only been one day... so we'll see in a week or so but for now its running great.

well problems is still there..... and i still have no idea what it is?!?! its only doing it when i sit in traffic.... stop, go, stop , go.... etc. whats the EGR do... i dont know anything about it really?!?! ... any help.. PLEASE

Thanks
Jason

Have you tried replacing the coil pack? I think thats what it is called.

coil pack was one of the first things i replaced

I bet you its your fuel pump.I had the same problem last year.I had a walbro fuel pump in my car.As soon as summer hit and it was really hot out,the car would start running hot and stalling out on me.I had to let the car sit for a couple of minutes before i could start it back up.It only happened in stop and go traffic,when i was on the highway it was fine.As soon as i replaced the pump it ran mint.I suggest you change your fuel pump.


Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust

The overheating in stop-n-go traffic after replacing the thermostat sounds like you have trapped air in the cooling system, especially if you hear bubbling but it doesn't boil over. The only way I know to remove air from the system is to completely drain all the antifreeze, start the engine and slowly refill the system. Keep an eye on the temp guage to see when the thermostat opens to make sure the whole system is full.

EGR valve - Exhaust Gas Recycling. It's a valve that allows a small amount of exhaust gas to be sucked in to the intake to reduce emissions and lower combustion temps. It doesn't allow any exhaust gas through at wide open throttle, so blocking it off won't make your car faster. Since it deals with exhaust gasses, it does get carbon deposits on it. You can clean it with carb cleaner after you take it off. It's on the top-right of the engine, looks like a 2-inch diameter soup can with a 4 wire clip on the top. Where the EGR bolts on, there's a small mesh covered tube that goes to the intake manifold under the throttle body. Be sure to get a new gasket and some high-temp sealer first.

I have a 97 sunfire with the 2.4, and I replaced my EGR valve, which is $200 for just the part. Don't jump to replace it until after you've tried to clean the existing valve.

Hope this helps

.


John Wilken
2002 Cavalier
2.2 Vin code 4
Auto

fuel pump i think is my next guess.... if that doesnt work then i might try for injectors... i'm really getting sick of this guessing game... and its getting to be expensive. thanks for you help guys and thanks for explaining the EGR .

Just one question, how is this a fuel-related problem if he had it started up and it ran GREAT?

Just doesn't make sense, but it does sound like either your fan isn't kicking on (is it????) or there either air in the coolant or not enough mixture (50/50 mix of dexcool and water).

Did your mechanic use Dexcool or green stuff? My 97 2.4L uses Dexcool, so I would assume your 98 2.4L alsu uses it. Rumor has it if you mix the green and the orange it produces sludge and crap like that, I have never tried it.

As for removal of air in the line, the above suggestion is not entirely accurate. Any time you open the system, air will get in there, whether you fill it or not. To get rid of the air, I squeeze the upper hose several times w. the radiator cap off (or the pressure cap off the resivuar (spelling sucks). You will see it bubble, that is the air. Do that about 4 or 5 times and you shouldn't have a problem, unless the thermostat is defective. Also, in stop-and-go traffic, it is not uncommon for overheating because the air is not moving and cooling the radiator. I always overheat when I am stopped after driving for alittle while. And I always go past my 1/2 way mark on the gauge at the track if I race too many passes. Hope this helps.

Sam


Ban low-performance cars, not high-performance ones.

ok ... just to clear it up a lil.... its not over heating at all... the cooling system is running just fine. this problem is either electrical or fuel related..... thanks anyway