ok so my firechicken is having issues and i cant figure it out. when it gets hot (running temp), it like to die when i am not in the throttle. the idle isnt too low it just seems like it bogs out and dies. i am looking at the battery gauge and its bouncing and reading low. obviously i ruled this a battery/alt probl;em, so i got them tested. bad battery, great reason for a new pretty optima. problem comes back later in the day. so i tested the alt and it tests normal unless it is having the issue and rpms are going up and down and its not putting out enough juice. i replaced the alt, same problem. i have a cam and headers back exhaust with a tune. the cam is pretty big, not sure of specifics bc i just bought the car an the previous owner didnt tell me. not sure what else bc everything happens only when its hot and it all seems like its just not powering right. i just wanna get it fixed w/o taking it somewhere bc i am not the best at diagnostics but i can install pretty much everything. oh and if i give it gas, about 1500+ rpms, it runs fine, until i run it like that for a while. then even up to 2 grand it spits and sputters. i can still get around in her limpoing but its killing me. please help, im tired of buying random parts just to be wasting my money. thanks guys

 

Maybe a vacume leak? Whats the emissions mod done? Theres a tube that is covered with insulation that is hard to locate in the back of the manifold, strip the coating off and have a look. That caused all kinds of issues , bogging on tip in was one.

 

You need to get it scanned, while the engine is running. Not just a code reader.

Could be a failing cooling temp sensor. All kinds of wierd **** happens when they start to go. Is it a 1998???

You may need an 02 sensor(s).
Very dirty fuel filter.
Dirty fuel injectors.
Failing cam position sensor.

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check the under hood fuses in one of the fuse boxes under the hood there is a fuse labeled eng sensor fuse check that my car had similar issues checked every thing and found that fuse was blown.

 

its an 02... ummm, i really think its electrical bc i am not getting any type of code. i mean maybe a vacuum hose but wouldnt it constantly have that issue/? also, the guy who sold it to me said it needs a waterpump. i bought one with the car but havent had any issues with it overheating at all. the temp gets right dead center and stays. maybe the guage just isnt reading that its too hot and i am running too hot and its naturally shutting off? i am still new to the ls1/ws6 world so im not sure what all type of issues they have. idk if it helps but the car have just over 100k miles and the motor is STRONG and runs without skipping a beat... oh and its not a fuse, unless their are fuses inside the car? only ones i found were the ones by the front left fender

 

Not a vacuum leak, they make the engine rev UP, not down.

When the engine shuts off, does it start up again just fine? Or does it really struggle to turn over.....
If its getting so hot that its struggling to turn over, then its getting HOT!!!

You should always be able to pop the hood and put your hand on the intake and keep it there. If you cannot keep your hand on the intake for more than 1-2 seconds without getting burned.....then you know it really is getting WAY TOO hot.

That would lead to what I said earlier....failing temp sensor. And some cars cannot run without a temp sensor. They spit, backfire and feel like its running on 1 cylinder when they are acting up.

As far as the codes go.......LSx cars suck at some things when it comes to throwing a code. Not all LSx PCMs act the same either. You WILL NOT get a code for failing sensors with some peoples PCM's, and some other items, till they are COMPLETELY failed, then you get a code.....makes it very hard to find problems sometimes.

Failing 02 sensor(s) are one of those things......thats why you need to do a real scan, with a real scanner, while the engine is running.....to see how the 02 sensors are switching. Failing 02 sensors will cause an engine to bog down and shut off when down low in the rpm range, but when you give it throttle they will take off and seem ok. You will also "usually" run rich with failing 02's....so see if you smell raw fuel in the tailpipes when its spitting and bogging.

Electrical problems do cause some wierd ****....but I've never heard of one causing your issues.

See if the engine is getting way too hot.......by feeling the intake......you won't be able to touch anything under the hood if its really getting too hot, everything will be untouchable.

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wow very helpful man, honestly i would be running up to the car to look at everything your talking about right now if it wasnt so damn loud and 130 in the morning lol. what your saying makes alot of sence (sp?). anyway, the temp thing kinda sounds like a probable. it starts depending on how hot or how long the problem has been going on. when it dies the first time it starts right back up like nothing but when it idles down it dies. and i keep it reved and eventually it goes from holding it above 1100 rpm to like today i had no choice but to make it back and it started bogging and dying at 2G rpm. it seems the longer i run it like that the worse it gets but it always starts right up after at most 5 minutes from it dying regaurdless of how hot it is. sometimes when it dies it wont start it just goes down to 1-3 hundred rpm for about 5-20 seconds and eventually dies. i am getting pretty confident in it just overheating. tomorrrow i will replace the waterpump, and compressor bc i have one and it needs it anyway. i will update you guys and tell you how it turns out. anything i should know about swapping the waterpump? i have done them before but i know their are tricks or things to look out for in any car or anyjob. thanks again everyone, i was really getting pretty depressed but now i feel like i have some more to look forward to and some sort of confidence

 

Like LS6427 says, this is one of those times when hooking the car up to a live scanner, not a code reader, really helps; that way you can see exactly what's going on with the car as it runs in real-time.

Also, be careful with that 'temp gauge-I think on all models after the '98 year the 'temp gauge isn't spot-on accurate. Most people refer to it as a "dummy gauge" because it's not giving you the correct temperature readings. I know it makes no sense, but just watch out for it.

I'd follow LS6's advice and look at the following:
Very dirty fuel filter.
Dirty fuel injectors.
Failing cam position sensor.
02 sensor...

Although at the last two you might need the help of a real-time scanner (at a shop) if the PCM isn't throwing codes. Good luck and keep us posted...

 

Water pump is cake. No tricks that I know of. Its straight forward. Don't have to remove the TB either, some people do but not necassary. Of course, go get new gaskets at the dealership, they were like $18.00 I think when I did it once.

Remember though......the water pump will always flow coolant normally, so its certainly not the cause of any overheating that may be happening. Bad water pumps just leak from the blown seal (through the weep hole on the bottom center area of the pump), thats why they get replaced, not because they stop flowing coolant. If you were the one in a million who actually shears a water pump shaft, then it would overheat right into the red in 15 minutes and stay there.....no coolant at all would move anywhere.
If its not leaking...I'd leave it alone man.....

Get a scan....then let us know what they find. BEFORE you go buying **** and spending money on anything.

Good luck.......

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I had similar issues, the car would run fine, then just die at lights for no reason. I could start it up right away. After a week or two, it would take 10-15 minutes to get it started again. The last time it happened, I had to get it towed. I replaced O2 sensors, cam position sensor... no change. Then I replaced the crank position sensor and all was good. it's easy to replace, it's just under the starter.