Car jolts when boosting?

[deputy865]

I tried to search, didnt find anything similar..

My car spits/sputters/jolts/pops when im at about 23% Throttle and up.. Or when i get to about 2-3 psi and up. I have no idea why its doing this. I noticed the other day when driving the car would not "pick up" very quick. The car is boosting fine, just jolts.. Also, my (cheap) Air/Fuel gaugeALWAYS is on the "rich" side during normal driving conditions.. When it starts doing this it flickers frantically around the Lean/Stoich area. I also have a exhaust leak up front from the o2 housing/downpipe connection. Not sure if any of that helps, but i REALLY want to get this taken care of as i am trying to sell the car

I appreciate the help!

Shane

 

[mindset]

Sounds like you need some new spark plugs and wires. My car did that and once I changed the plugs and wires it stopped and ran smooth when boosting.

 

[gofer]

3 words, boost leak test. when i start noticing some hesitation going into boost thats the first thing i do. changing your spark plugs probably wouldn't be a bad idea either depending on how long its been. While your at it you can trash that narrowband disco show going on while your driving as well, that thing will tell you nothing useful. Sell it on ebay or craigslist to a honduh guy... i did the same thing when i first got my car, put the $40 you get for it into a wideband that you can use.

boost leaks are your culprit though.

 

[deputy865]

I wouldnt think a boost leak test would do this though..

I forgot to mention that i overheated before this started happening.. Could i have really messed up a spark plug? Thats what it seems like and feels like..

Its not the head gasket...

Shane

 

[92rsAWD4me]

When I was trying to get my car smogged it did a similar thing. It kinda sounded like it was missing and different such things. What ended up happening was I had a shop clean out the egr and the ports for it. I'd say take off you intake pipes and the TB elbow and see what it looks like, also you can take off your egr valve and see if there is alot or carbon build up in there as this could also cause strange things with running/ pick up. I'm pretty sure there is a tech article or perhaps something in the faq section about how to properly clean the TB.

 

[Dsmj89]

Start with the simple stuff, change your spark plugs out and see if the problem goes away, if not, proceed to change your spark plug wires as well.
Make sure all your intercooler pipes are intact and fastened down real good.

 

[deputy865]

Alright, ill replace the plugs. Clean the TB and make sure all my pipes are good and go from there.

Shane

 

[deputy865]

Well i changed out the spark plugs.. That fixed like 80% of the problem. It still does the same thing, but at 10psi+ now. Any ideas? All the plug wires appear to be fine.

I put NGKBPR6E's gapped to .28 in the car

Could this just be a stupid boost leak problem or something else? Maybe my air filter? I have a bad one. Hope its not the wires. The wire kits are like $50 at Autozone..

thanks!

Shane

 

[knochgoon24]

Yes, it's probably a boost leak. Just build yourself a tester. When my car was stuttering real bad it was a combination of bad plugs and a boost leak.

Chances are, if you haven't replaced the throttle body shaft seals, those are leaking.

 

[deputy865]

Are the TB seals cheap to replace? Easy? I might as well clean the TB while im at it right?

Thanks,

Shane

 

[knochgoon24]

Are the TB seals cheap to replace? Easy? I might as well clean the TB while im at it right?

Thanks,

Shane

They're usually pretty cheap. $15 or less. Replacing them takes a little while, because you have to disconnect the TB then take it apart. It's one of the best pieces of maintained I've done to my car.

STM has them for $12 + shipping.
STM - DSM ENGINE COMPONENTS | PISTONS | RODS | CAMS | TIMING | OIL COOLERS | GASKETS
You'll also want new gaskets for on both sides. $8 + shipping.
STM - DSM INTAKE | MANIFOLDS | FILTERS | GASKETS
You might want to replace the o-ring on your BISS screw while you're at it. A local hardware store should have the size that fits.
(Just for examples on pricing.)

 

[deputy865]

Can I get that stuff at autozone or similar chain stores? I need to fix this fast because im selling the car.. I need to sell it fast, and im not selling it until I fix it haha.. Get it?

Shane

 

[knochgoon24]

I'm not sure about the TB seals. They do have TB gaskets, but it's hit or miss where I live. Only one store actually carries them in stock all the time, and that's because the manager owns an Eclipse.

STM ships quick. I know because I usually order through them. Give them a call tomorrow and see what they can do for you.

 

[deputy865]

Do you really think that's what's wrong with my car though? I know that's a broad question to ask.. But I just want to try to be sure

Shane

 

[knochgoon24]

Do you really think that's what's wrong with my car though? I know that's a broad question to ask.. But I just want to try to be sure

Shane

Boost leaks or spark plugs have always been the cause of my car stumbling. Until you boost leak test your system, you won't know for sure.

 

[deputy865]

Well the last time I did a boost leak test, I didn't hear a thing.. I was just preasurizing the car to 15psi and I would stop and listen. Heard nothing. Anything im doing wrong?

I replaced the plugs and gapped them. Not the wires though. I tightened every pipe that air goes through. I bought a new air filter.

I have an exhaust leak up front from the o2 housing and down pipe connection.

The car will hit 10psi and will sound "broken up".. Like a lawn mower. It won't accelerate very well either at that point. The car starts to run "lein" according to my circus light show A/F guage.

Shane

 

[knochgoon24]

Running lean would imply that it's probably not a boost leak, as they usually cause you to run rich.
Do you have any way to post a log?

 

[deputy865]

No I don't. Its the cheap ass air/fuel ratio.. Ill post a video tomorrow of what the guages do. If my camera doesn't crap out ill try to get a audio clip of what the car sounds like.

But picture driving fine, accelerating. Hit 10psi, the car now sounds like a lawn mower, and accelerates VERY slowly and is choppy..

Shane

 

[deputy865]

Is there a way to check if my spark plug wires are bad? Sorry for the double post, its easier to do a new post then to edit from my phone..

Shane

 

[knochgoon24]

Take a multimeter and check the resistance of the wires. 10k-15k ohm or less per foot length is acceptable for non-performance wires. A broken wire will read infinity, and a corroded or damaged wire will read some where over 15k ohm per foot or higher.

You can also look for your wires to be arcing. Take off the spark plug cover and start the car when it's dark, then watch for any arching.

 

[deputy865]

I think ill just replace them.. New spark plugs fixed half of the problem.. Im sure wires are the other half.

Shane