backfire,hissing and stalling

[apexi287]

i dunno whats going on all my vacuum lines are connected i dont see any hoses that are not connected and when i start up my car i sometimes get a little backfire..then close to the firewall intake side i have this load hissing noise that sounds like a really bad air leak..itll struggle to stay on then stall..ive looked around the intake area forever and cant find were the problem might be please help its pissing me off!!..thanks

 

[YoNkErS87t]

Does it backfire from the intake or exhaust?

And did the car start this out of nowhere or did you do something under the hood and now it does it?

Check your codes also. that shoud be the first thing you do

 

[apexi287]

it backfires from the exhaust..after it stalls it also gets a small gas smell near the intake..the shop replaced my cylinder head and headgasket along with all new gaskets everywere..they said they had it running fine it just leaked from the camseals so i said id replace them because it was gonna take them another week or two just to get to that done..when i replaced the seals i also retourqed my headbolts to make sure they were at the proper 75ft/lb then i put everything back together i didnt even touch anything near where the noise is coming from the intake manifold looks nice and tight so i dont think its that either i have no clue..how do i check codes?..also the egr(i think thats what its called) the thing connected to the side of the intake manifold has one bolt that just goes round and round it wont tighten but i felt around that while the car was idiling for the little amount of time it was and i felt no air out of that..so i doubt thats it and its a pretty loud hiss

 

[mrnickleye]

While the engine is idling, spray some carb cleaner or brake cleaner around all the gasket mating areas. If the idle changes, spray some more in that spot to find out exactly where it is. Sounds like there might be a gasket leak.

 

[miggles]

when u replaced your cam seal did u set the cams on tdc?(top dead center) if your cams are out then you may need to reset them.

 

[havocatl]

Did you disconnect your battery while you were doing the engine work? If so, your ECU reset and it might need to relearn.

Are you running any codes? If not, take the car for a 40 mile drive on an interstate if possible. After my rebuild i had the same issue with backfiring, idle problems and the car would idle low after warmup.

Let us know how it goes.

 

[lagged]

check the timing.

 

[apexi287]

timing is good its all dead center no leaks with any liquid..just that load hissing from the intake manifold side im about to take of the intak manifold and check again to make sure all the bolts are tight on the head and the seals are fine..im guessing its a seal issue with the manifold..if not im sure ill see the issue on the way because i kno its that are so we'll see how it goess ill keep you guys updated but if anyone else has any thoughts or suggestions please feel free to give me your $.02..thanks

 

[gp-7mgte]

i am also having a similar problem. i just did my HG and i got the car to start but it is was lacking power, and then after i drovwe for like 20 miles, i moved i stalled and now the car doent wanna start. The timming is fine on the cams, and the cam position sensor. need help cannot it out i got to frustrated with it for one day.

 

[apexi287]

ok so i took of the entire intake manifold put new gaskets and sealant on and tighten the bolts as tight as i possibly could all the vacuum lines are connected in that area but i still get a really bad hissing noise i have no clue now..also my temperature gauge doesnt work and the fan doesnt kick on..would that be a bad thermostat?..please help i need my car..thanks

 

[suprabad]

YOU HAVE TO FIND THE VACUUM LEAK! THAT IS THE PROBLEM! Sorry to have to yell but you've already been given the answer by mrnickleye.

Forget the 40 mile drive
Forget the cam seals
Forget all that shit

Get a can of carb cleaner and start spraying it around where you hear the hissing sound and zero in on the vacuum leak by listening for the change in idle speed when you spray the carb cleaner. This is the easiest way to find the leak.

Sounds like your panicking...I understand, but you can't fix the leak untill you find it, so be calm, call your mom, have a smoke, drink a coke, tell a joke and then go into the garage w/ your carb cleaner and find, then fix the leak.

 

[apexi287]

so i just spray it sparatically where i hear the hiss?..how will i kno were it is when i spray it what will the carb cleaner do when its at the area of the leak?..also how do i check my codes?

 

[apexi287]

ok i just replaced every single vacuum line and still i have a hiss the same amount it doesnt stall as easily now but i also put fuel injector cleaner in the gas which im sure was part of it..im about to replace my o2 sensor to maybe stop or atleast help the stalling issue..i just need to find that fucking leak or whatever it is cuz right now i have no clue since i just replaced every vacuum hose..please if anyone has anymore ideas on what i can check or anything please let me know..thanks

 

[mrnickleye]

While the engine is idling, spray some carb cleaner or brake cleaner around all the gasket mating areas. If the idle changes, spray some more in that spot to find out exactly where it is. Sounds like there might be a gasket leak.

Thats...gasket leak, not vacuum hose leak. use the red stem on the carb spray to get as close along the gasket areas of the intake manifold, and related parts as possible.

When you spray in the leak, the fluid will get sucked into the manifold and cause the engine idle to change. Try it a couple more times in that spot to narrow it down to the exact spot. Then repair as needed, like new gasket.

Don't bother trying to plug a leak with silicone gasket adhesive, because it will get sucked into the hole and not do the job. (tried that 20 years ago)

I would not start throwing parts at it, like O2 sensor. Waste of $$.

Vacuum leaks will cause different kinds of running problems, depending where the leak is. The computer may sense the lean condition and try to compensate for it by richening the mixture.

 

[apexi287]

ok well i found the problme and fixed it my injector o-rings were bad and were letting in unmetered air

 

[QWIKSTRIKE]

Cps could be the culprit. those wires fail and need to be rewired or new harness is needed!

So if a problem likes this occurs in future look into cps also. Glad to see you fixed it; However never seen an O ring cause this. They usually just leak and just keep fuel from escaping. What O ring was it upper or lower.

 

[Suprastic]

hey,
for future reference I also had the same problem occur last light. First my car alarm got screw up because when I went to unlock it it was as if the batery was dead and the siren could hardly work. then finally it made the normal chirp noise it should. I go to start it and it fires up and stalls about 5 seconds later. Tried again same problem. Opened the hood and heard a leak. adjusted the intake etc. still a leake somewhere. then I wiggled the hoses on the charcoal canister and the leak immediately disappeared. Came back for two seconds did the smae thing to it and never came back as far as I knew. Car started fine after that after about a 3-5 sec hesitation at idle.

PS: if anyone knows why my alarm keeps shutting my battery down and reseting everything in the car let me now. I need to fix it.

 

[apexi287]

it was the o-rings into the cylinder head they were completely cracked and frailed another guy on this forum had this exact same issue..but yeah i wouldnt think it would be that either