My engine sputters when given throttle and if you give it hard throttle it backfires through the throttle body. The car has been sitting for quite some time and I did a full tune up put injector cleaner in it and its a little bit better once it warms up it doesn't sputter as bad but will still back fire under hard throttle. I'm thinking it could be bad injectors? Or maybe some vacuum leak there are some vacuum hoses that are just hanging in the engine bay and I cant find where they go.

 

Well until you figure out where your vacuum lines goes its going to be hard to diagnose anything other than a serious vacuum leak. Sometimes a vacuum leak will only make itself known under acceleration when the car hesitates or wants to stall when given more throttle. Shoot up some pics of the engine bay and the loose vacuum lines and maybe we can help you figure out where they go

Ive had problems with vacuum leaks and hesitation in the past so I'm pretty used to it I got it all sorted out though now.

 

Thanks for the response FireInMe17 I'll take pics tomorrow i forgot to mention when started cold it dies unless you keep your foot on the throttle.

 

Theres no dount in my mind that you have a massive vacuum leak somewhere. If you say you have vacuum lines disconnected everywhere, hell, just having one unplugged would send my car into a tizzy!

 

well I found were the vacuum hose went and the only improvement I got was it starts quicker but its still doing the same thing. I think im going to get a can of starter fluid and spray around the hoses see how that goes. I'm thinking it could be the injectors from the car sitting for 8 years and not only that at one point someone poured sugar into the old gas tank and we had to replace the fuel pump, gas tank, and fuel filter about 5 years ago.

 

Seafoam it first, it cant hurt to try($8 bucks for seafoam vs $60 or so for a cheap injector) Just because you figured out where one vacuum line goes doesnt mean that it was the only one that was causing a problem.

I like to use wd-40 or carb/throttle body cleaner to check for vacuum leaks. Spray the ends of vacuum lines, intake gaskets, check your PVC valve and grommet on the valve cover, if you can take apart and clean your throttle body and it just helps to take off, and adjust IACV and TPS sensors, if they are off they can also cause problems.

You can't clean a TPS sensor, but you can take apart a IACV and clean it, I would suggest doing that too.

Check your air filter too while your at it, when i got my car it had a really old air filter in it and it was almost black, now it has a K&N and i could really tell the difference just from a new air filter.

Then if your car has an EGR valve on it (I dont know if it does) see if you can get that off and clean it out, if it gets stuck open it can act the exact same way as a vacuum leak.

You just have to make sure that everything is sealed up, at least I would start to see if my problem was an idle air problem rather than a fuel problem at first, idle air problems are a lot cheaper to get fixed than a few new injectors would be.

Its just little trouble shooting problems like these that can help out alot, You'd be surprised just how differently my car will run if theres a vacuum loss or a sensor is out of wack.

I hope this helps.

 

Mine does the same exact thing, I've yet to investigate and start throwing parts at it but with my endless hours of research I've come upon a few solutions. Mine gets better as it warms up but not great.

Timing
Coolant Temperature Sensor
Manifold Air Temperature Sensor
Injectors (bad or need to be cleaned)
Leak in your throttle body and or intake.

Your problem doesn't seem to be a vacuum leak, but then again I could be wrong as you said they seemed to be all over the place.

 

Yeah, thats why it would be better to get vacuum restored first off and make sure that those systems are working correctly if there are loose vacuum wires, then if that doesn't work(which it may or may not) then the way to go would be fuel, ignition, etc...

I try to work with whats already on the car and see what you can do before you start throwing parts at the problem, most of the time you don't need nearly as many new parts as you would think.

 

You could try Seafoam, it happens to be a great product, but your car has been sitting for 8 years. Whenever you use any kind of fuel additive as it flushes through the lines, it is flushing the dirt and debris right into the screens/filters of the injectors. The additives work, but sometimes it is a temporary fix depending on the condition of the injectors.

Sometimes you are just better off having them cleaned and flowtested. It allows us to visually inspect each one to see if they are functioning properly.

If all else fails, and you continue to question your injectors.
We will be happy to place them onto our flow bench to see if there is a problem with them.....NO charge!



send us a PM, email at info@southbayfuelinjectors.com
or call at 516-492-6504

 

How long have you been running this car? How long has it been since you ressurected it? Mine sat for 4 years and I had two injectors go bad, but not after 9 or 10 months of use after I started driving it everyday. I agree with southbay08 its just one thing at a time, and vacuum would logically be the best place to start, I think.

 

Ive had it for about 3 weeks now and have done full tune up and been starting it everyday since i got it. I wasn't able to do anything with it today because we got bad rain here in Florida. Tomorrow I'm going to go buy vacuum hoses being they are all dry rotted and cracked and get some Seafoam treatment and go from there. Ill let you know if I see any improvement. I appreciate the input guys this site has helped me a bunch especially when I had my firebird.

 

Good luck

 

I wasn't able to work on the car today but i did start it and the ses light came on and i checked it and i got code 34 which is maf or map sensor according to chilton's repair manual so could this be the cause of the problems? I just got done spraying starter fluid around all vacuum lines just to check and no change in idle.

 

Hell yeah! A bad MAF/MAP sensor will mess these things up big time! And cause vacuum problems as well lol

 

 

I got the maf today couldn't get the metal clamp back on so i just wrapped electrical tape around it. once i had everything hooked back up and fired it up it did the same as before for a little while and threw a code again and then it went away. Let it sit for a little while went to start up no problems now it runs smooth and starts right up thanks to everyone who helped out now im going to get started on the interior