Yes... you heard right. I'm offering a $50 reward to the person who's answer and know how solves the following problem on my brothers car. I will paypal it to you or whatever, im just getting desperate. I'm very serious and this is not a joke. I've been on this site for 7 years now and my word should be good around here.
Anyways. The car is a 2000 Cavalier with a 2.4 and a 5-speed transmission. It is equipped with the gmpp supercharger.
The problem..... Misfiring under load. No codes, the damn thing wont throw any. It did have a P0300 at one point but wont throw the code anymore. If you drive the car like a grandpa and don't get on it, the car runs and drives fine. As soon as you step on it though it will start to misfire. It only does it when the fuel pressure goes above 50 psi (yes there is a fuel pressure gauge in the car... the unit is threaded into the fuel rail right before the regulator). once the car goes past its peak power and the fuel pressure drops back down below 50psi it runs great. Car runs great at idle also
It's not isolated to one cylinder. I've been using a snap-on modis scan tool and looking at the misfiring data... and all 4 cylinders will do it. Sometimes cylinder 2, 3, and 4 will do it, other times just cylinder 2, maybe 1 and 3... its just back and forth on all the cylinders.
Like stated above it only does it when the fuel pressure goes above 50 psi.
Ok... last.... the parts list of stuff ive already tried to fix/replace
- New fuel pump
- new map sensor
- new crank sensor (relearned of course)
- new coils
- new plugs (acdelco 41602 gapped at .050)
- new spark boots
- 3 new different sets of coil cover housings
- tried 2 different used ignition modules
- new oxygen sensors (front and rear)
- tried 2 different used tps sensors
- tried 2 different used fuel pressure regulators
We are at a point in wanting to just torch the car. I'm frustrated and loosing weight and sleep over it. Someones gotta be able to help us on this.
fuel filter?
new plugs... one step colder, gapped I "think" at .035 is what some guys are doing. don't quote me.
check all grounds, maybe do the "big 3 upgrade".
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
fuel line have something in it?
wiring for fuel pump damaged?
wiring for IDI damaged?
I must confess... I feel like a monster!
first thing id do is gap the plugs to .035...
sounds lke spark blowout
Edited 1 time(s). Last edited Friday, October 30, 2009 4:07 PM
LE61T PTE6262 Powered 
ive head of a tps causing it in certin conditions
It does have a New fuel filter on it, It even blew the cat converter apart, replaced it and checked to make sure muffler was not clugged..........its been like this for two months, and still have not figured it out. So any help or input would be great, and whats the Big 3 upgrade??? thanks
Oh and when i built the car at 55,XXX miles and currently has 70,xxx miles this is the first problem i have ever had with it, and the plugs were always gapped at .050. so i mean its not somthing i recently added that made it start this, it just started it while driving down the highway at normal speeds one day.
Qwibby {T3H Old QBE} has told you....spark flame out.....
You never know today what you're getting when installing new spark plugs...
Some are good, some are bad....
Maybe you can find out what's best from someone at the local drag strip....
Qwibby {T3H Old QBE} wrote:gap the plugs to .035
My best idea at this point. Troubleshooting online is always difficult for me.
ok i could try to gap them at .035
i doubt it would do anything... i already had them gapped to .040 at one point to see if that would help and it did nothing
Jumped a tooth on one of the cams when you rebuilt it
-----------------------------------------------------------------------
-----------------------------------------------------------------------
- Sold my beloved J in April 2010 -
I would put a fresh set of NGK stopck number #4177's in at .035, and see. What injectors, what other mods to the car?
FU Tuning
the injectors are the ones that came with the supercharger kit... and thats it as far as mods to the engine
Qwibby {T3H Old QBE} wrote:first thing id do is gap the plugs to .035...
sounds lke spark blowout
This is what im thinking too.
Tinkles
2003 Cavalier 1SV
Bagged and Blown
I had to drop the gap on mine down to .030 to keep from blowing out the spark.
meckster wrote:
- new plugs (acdelco 41602 gapped at .050)
That's your problem.
Use AC Delco R42LTS (GM-5613717) gapped to 0.050.
>>>For Sale? Clicky!<<<
-----The orginal Mr.Goodwrench on the JBO since 11/99-----
i understand what you guys are saying about the spark plugs but he put like 20,000 miles on this car with the current setup using the 41602's without any problem at all. I was talking to someone today about the problem and he said something about all the grounds in the engine bay, including the ones underneath the battery tray. Could that be it also if they are rusted to hell. I can't do anything with it till monday, its at work in the garage
You have a PM
- 2004 Cavalier - 124k, owned since new
spark plugs get used... so they wear down over time. Get new plugs, those NGK's and regap them to .035 and have a better day buddy....
random cylinders at random times - spark blowout
the GM 2.4 kits are notorious for it....
LE61T PTE6262 Powered
Qwibby {T3H Old QBE} wrote:spark plugs get used... so they wear down over time. Get new plugs, those NGK's and regap them to .035 and have a better day buddy....
random cylinders at random times - spark blowout
the GM 2.4 kits are notorious for it....
How is not gapping a plug to manufcature spec going to fix anything, and even if it did, you put a band aid on a broken arm. the problem is still there
What is "spark blowout" I've been a tech for several years, have never ONCE heard that term
- 2004 Cavalier - 124k, owned since new
Spark blowout happens when cylinder pressures get to high that the spark cannot jump the gap on the plug.
Edited 1 time(s). Last edited Sunday, November 01, 2009 6:19 PM
Tinkles
2003 Cavalier 1SV
Bagged and Blown
Tinkles wrote:Spark blowout happens when cylinder pressures get to high that the spark cannot jump the gap on the plug.
Sourced.
Okay but what would cause cylinder pressures to increase, lets see having a turbo or supercharger, the origianl poster speaks of neither.
The spark can jump the gap on just about any gap,it may run bad, but most cases if it isnt full of carbon of the gap is closed, it will atleast just the gap to make spark so there is some sort of combustion.
People recommending spark plugs are leading this guy down to a dead end
- 2004 Cavalier - 124k, owned since new
Rob wrote:Tinkles wrote:Spark blowout happens when cylinder pressures get to high that the spark cannot jump the gap on the plug.
Sourced.
Okay but what would cause cylinder pressures to increase, lets see having a turbo or supercharger, the origianl poster speaks of neither.
The spark can jump the gap on just about any gap,it may run bad, but most cases if it isnt full of carbon of the gap is closed, it will atleast just the gap to make spark so there is some sort of combustion.
People recommending spark plugs are leading this guy down to a dead end
meckster wrote:
Anyways. The car is a 2000 Cavalier with a 2.4 and a 5-speed transmission. It is equipped with the gmpp supercharger.
Lanman31337 -F = fatties = do not want. A little chunk in the junk is ok though.
Techs are so smart now a days........... lol
My guess is injectors, swap them out and see what is what, but the spark blow out seems valid, change the 4 and try it, its an easy check!
hahahah appartenly techs lack reading skills i would have said it was the plugs cause i had that issue with my car i replaced the plugs and wires and the problem went away but you have done all that and still have it.
a .035 gap is tighter but you shouldn't have a spark jumping issue as i'm moving more air though mine then you will be with your M45 and i'm gapped at .052
i would say get someone with HP tuners or has access to a Tech 2 from a GM dealer and get them to scan the car while your driving get the live data maybe something isn't reading right but isn't throughing a fault you can keep changing parts but you will dump a bunch of cash into it before you find the issue
JBO since July 30, 2001
