everytime boost gauge gets + car jerks badly

[lilpastrana]

i have a 91 plymouth laser rs, when im driving in anygear and kick it down the boost gauge goes up, and after a little while it will jerk very badly. ecspecially in 5th gear when giving it more gas to go up a hill, i had a major exhaust leak that i fixed and it stilll does it, when im driving and shift down and hold the clutch in the car dies somtimes, it idles under 500 rpm when warm, and it will almost die, then rev up on its own, it has new 02 censor, catilac converter is good, thats all ive tried, i took it to the shop the other day and he tet drove it he said that its not gettin enough gas when underpressure w/ the boost, he told me plugwires, or fuel filter i havent tried them yet

 

[eclipsh]

Check for vacuum leaks, especially to your boost control solenoid or MBC.

 

[VtecvrsTurbo]

To me it sounds like you havent had the car long, but have you ever done a boost leak test? See if you have air not making it to the engine.

 

[lilpastrana]

just got it like a week ago. Im new to dsm's how do i do a turbo leak check, also sometimes and turbo will work for a little while then the jerking will continue

 

[stirpicult]

if you have only had it for a week, then go ahead and do plugs and wires anyways. they probably need to be replaced, and it might solve your problem.

 

[VtecvrsTurbo]

Yes, so do a basic tune up and see if that helps any of the problem. If it does nothing then i belive that you do a leak test.

 

[eclipsh]

I still say it sounds like a vacuum leak, but it could be bad plugs and/or wires.

But rather than just running out and spending money on parts you may not need you may want to TEST those plug wires and do an inspection of your plugs. They may be fine.

The first things you should be getting are a Haynes or Chiltons manual and a multi-meter if you don't have one already. I would reccomend the Haynes as I've found some bad info in the Chiltons.

After that, go do some tests on the car and THEN replace anything that is not within spec.

Go visit this site and read all the links on this page. That should give you a good start on what you've gotten yourself into. May whatever diety you do/don't believe in have mercy on your soul/spirit/atoms. Welcome to the DSM world.

 

[lilpastrana]

i also noticed today that if i rise the boost gauge quickly it does not do it much, but if i raise it slowly like when aclerating up a hill it jerks a lot worse, but you can tell when the turbo hits and when it is working properly at 14lbs on the stock gauge.

 

[ddavisaf]

-Check your spark plugs, you must have NGK BPR6ES plugs gapped at .028". Nothing else will work. Period.
-Check your plug wires. Ohm them to make sure they're allowing the plugs to fire.
-Check your coil pack's resistance on both primary and secondary coils.

-Run a boost leak test via http://www.vfaq.com/mods/ICtester.html
-Get an aftermarket boost gauge.

 

[eclipsh]

That sounds a lot like you are getting too much boost. The factory boost gauge does not actually read pressure and is not accurate. You may have either a bad boost control solenoid or a leak going to it.

Does the jerking stop if you let up on the gas slightly? If so I can almost guarantee this is the problem. Throw on an aftermarket boost gauge and see what kind of pressure you are REALLY getting. If you need a cheap one a lot of diesil shops will have 'em or get a decent one that reads vacuum as well as boost for $50-60 at a parts store.

 

[9!'clipseDOHC]

Check your timming too, that could explain the cutting off and idleing low. The reving on its own could be your idle speed controller (ISC).

 

[lilpastrana]

alright thax for the fast replys guys. heres somthin else for ya, on my way to work tonite my alternator went out, now the jerking is very slight, and now the stock boost gauge will not over 7. but i can hear the turbo kick in and it is working from what i know, 1st turbo car ive ever owned, but for the turbo stuff, its goin to have to wait i need to get my alternator fixed and a new battery ill keep ya updated, and yes when the jerking started i would let of the gas slightly and it would stop jerking,

 

[ddavisaf]

-Check your spark plugs, you must have NGK BPR6ES plugs gapped at .028". Nothing else will work. Period.
-Check your plug wires. Ohm them to make sure they're allowing the plugs to fire.
-Check your coil pack's resistance on both primary and secondary coils.

-Run a boost leak test via http://www.vfaq.com/mods/ICtester.html
-Get an aftermarket boost gauge.

I'll reiterate.
The first three are 99% the problem. If they're not, run a boost leak test via the link and post your results. If you have any questions post them along with any information you have from the three original things I told you to check. Plugs/Wires/Coil

 

[Benag]

My car did this same thing once. It would jerk really bad when accelerating especially when I was low on fuel. I just changed the fuel filter and it started working perfectly again. Do this at least to root it out. Filters are only like 20 bucks.

 

[stuntman]

My car is a n/t auto tranny 2.0 and it does that same jerking at highway speeds after about ten minutes or so of driving. Would everything said apply to me also even though it is a n/t?

 

[ddavisaf]

Yes and No.
Testing your ignition system is always the first step though. However since your car isn't dependent upon boost the spark plugs are less of an issue.
Your steps would be....
-Check and make sure your spark plugs are not fouled (I still don't recommend running platinum's, NGK all the way)
-Check your plug wires
-Test your Coil Pack's primary and Seconday coils.
-Replace the fuel filter

After you've tested/replaced these components and everything is in good order post your results. If you're experiencing the jerking problem still on the highway we'll troubleshoot some more.

Also, when you test your coil test it hot. I've seen coil packs have problem when they're hot only. Just something to keep in mind.

 

[lilpastrana]

hey, i have another question for ya, when i 1st got the car when i 1st started it the alternator belt snapped right away, replaced it and the alternator was fine the battery was taking a charge, few nites ago i had to push start my car to get ti started and i couldnt drive cuz the battery was so low the lites were very dim, so i charged the battery, turned on my stero...amp, subs.. cd player a little while later same damn thing, i looked down at my alternetor and there is rubber shavings everywhere from my belt?.. i m for sure it is from the new belt. Is there anyway that the alternator could have went bad from my amp? its a 1200 watt rockford amp. ???

 

[ddavisaf]

Check your crank pully for signs of seperation. Your amp will not damage a belt, it will just overwork the alternator. Also, make sure all the contacts on your battery are clean and clear of corrosion.

 

[lilpastrana]

ok, got the alternator situation, now my subs wont hit? i got them to hit once when the car was just on acc. then i started it and they didnt work...? i know i got power going to the subs, the rem wire is good, and the ground.. makes no sence, help me