Very bad misfiring with any amount of boost?
Thread Starter
10 Second Club
iTrader: (22)
Joined: Mar 2006
Posts: 3,677
Likes: 2
From: Northwest side of Chicago
Very bad misfiring with any amount of boost? 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
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.
Thread Starter
10 Second Club
iTrader: (22)
Joined: Mar 2006
Posts: 3,677
Likes: 2
From: Northwest side of Chicago
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?
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
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Thread Starter
10 Second Club
iTrader: (22)
Joined: Mar 2006
Posts: 3,677
Likes: 2
From: Northwest side of Chicago
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?
I had a plug wire do the same thing. Ran fine at any rpm out of boost.
I know you don't need another person saying ignition, but sometimes you can check these things 10 times and on the 11th you find it.
I know you don't need another person saying ignition, but sometimes you can check these things 10 times and on the 11th you find it.
Thread Starter
10 Second Club
iTrader: (22)
Joined: Mar 2006
Posts: 3,677
Likes: 2
From: Northwest side of Chicago
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.
Thread Starter
10 Second Club
iTrader: (22)
Joined: Mar 2006
Posts: 3,677
Likes: 2
From: Northwest side of Chicago
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.
Thread Starter
10 Second Club
iTrader: (22)
Joined: Mar 2006
Posts: 3,677
Likes: 2
From: Northwest side of Chicago
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
