Very bad misfiring with any amount of boost?
#1
10 Second Club
Thread Starter
iTrader: (22)
Join Date: Mar 2006
Location: Northwest side of Chicago
Posts: 3,677
Likes: 0
Received 2 Likes
on
2 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
So i just pulled the car out of storage friday night. The car runs good around town but when i get into any boost it starts popping and misfiring. Even on the highway at 75mph with the converter locked,i give it 1/8 throttle and build up maybe 1-3psi and it starts jerking and misfiring badly.
Plugs are gapped at.025,the wires are new msds,timing is 18 degrees total. At first i thought it was the 4 month old gas,so i burned through that tank and filled up with 4 gallons of 100 and the rest 93octance with no change.
Any idea?
Alex
Plugs are gapped at.025,the wires are new msds,timing is 18 degrees total. At first i thought it was the 4 month old gas,so i burned through that tank and filled up with 4 gallons of 100 and the rest 93octance with no change.
Any idea?
Alex
#2
TECH Regular
iTrader: (17)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
So i just pulled the car out of storage friday night. The car runs good around town but when i get into any boost it starts popping and misfiring. Even on the highway at 75mph with the converter locked,i give it 1/8 throttle and build up maybe 1-3psi and it starts jerking and misfiring badly.
Plugs are gapped at.025,the wires are new msds,timing is 18 degrees total. At first i thought it was the 4 month old gas,so i burned through that tank and filled up with 4 gallons of 100 and the rest 93octance with no change.
Any idea?
Alex
Plugs are gapped at.025,the wires are new msds,timing is 18 degrees total. At first i thought it was the 4 month old gas,so i burned through that tank and filled up with 4 gallons of 100 and the rest 93octance with no change.
Any idea?
Alex
I have seen or personally dealt with each of these problems.
Start with the simple stuff for obvious reasons.
Let us know what you find.
#4
10 Second Club
Thread Starter
iTrader: (22)
Join Date: Mar 2006
Location: Northwest side of Chicago
Posts: 3,677
Likes: 0
Received 2 Likes
on
2 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I have a wideband and a fuel psi gauge in the car. A/f is 11.4 and the pressure is about 70psi. Brand new lonnies dual intank setup. The fuel pumps and spark plugs wires have about 50miles on them. I put them friday night before i even started the car. I guess i could have a coil issue. How can i check these coils?
#7
9 Second Club
iTrader: (8)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I have the same problem with my engine. I just got my LSX 427 running and around 3K to 3.5K rpms it would sputter and misfire bad. I am running my car in open loop so I know it isn't an O2 sensor problem. I am going to try a set of square truck coils to see what that does. What is weird is that I never had this problem last year with my 402 and basically the same setup.
Trending Topics
#10
10 Second Club
Thread Starter
iTrader: (22)
Join Date: Mar 2006
Location: Northwest side of Chicago
Posts: 3,677
Likes: 0
Received 2 Likes
on
2 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I just drove the car and with a cold engine it didnt misfire. Im thinking maybe because it was in open loop. Also car has developed a slight surging at low speeds that isnt there in open loop either. I tried to disconnect my coolant sensor to put it in open loop and the car wouldnt start with it disconnected. Can i just disconnect my frt o2s?
#12
10 Second Club
Thread Starter
iTrader: (22)
Join Date: Mar 2006
Location: Northwest side of Chicago
Posts: 3,677
Likes: 0
Received 2 Likes
on
2 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Im going to pull them all off anyway just to check. I know the msds are not the best but they were the only ones if found with a universal set for ls1. I need to make custom length ones for the turbo kit im running.
#14
10 Second Club
Thread Starter
iTrader: (22)
Join Date: Mar 2006
Location: Northwest side of Chicago
Posts: 3,677
Likes: 0
Received 2 Likes
on
2 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Im thinking it should be about 20-30 ohms on an msd. But sometimes the resistance can be okay but if its arching through the insulation it could still cause a problem.
On a side note i put the car in open loop and it still pops alittle. Im thinking some kind of ignition problem. It also is only building about 11lbs where before it would do 14lbs.
On a side note i put the car in open loop and it still pops alittle. Im thinking some kind of ignition problem. It also is only building about 11lbs where before it would do 14lbs.
#16
10 Second Club
Thread Starter
iTrader: (22)
Join Date: Mar 2006
Location: Northwest side of Chicago
Posts: 3,677
Likes: 0
Received 2 Likes
on
2 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I checked for boost leaks and couldnt find any. Even if there was a leak would that cause the car to misfire alot. I could see loosing alot of power but not misfiring