Low rpm sputter
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
I’m still having this issue. I decided to put a cam sensor in but found other issues with the intake. Found two broken runner seals on my fast 102. And the intake hitting on the head bolts. Had to notch the intake to clear them. The car runs way harder now but still occasionally doing the sputter. I’m starting to think the fuel injectors are leaking. I feel like it doesn’t hold fuel pressure long enough. I had the fuel pump in and out probably 50 times. I’m confident that it’s not leaking in the tank. I can’t find any leaks outside the tank. So I’m thinking fuel injectors.
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
So first time it’s done this car completely didn’t want to start. Kept cranking and cranking finally started after giving it some gas. I had to keep it running sounded like it just dumped a **** load of gas down the cylinders.
As I said in the 2nd post, it seems like a vacuum leak to me. You might want to pull the intake back off, check all your seals, and clean all surfaces. When you re-install it, the torque sequence is critical. Do not over-torque the intake bolts. It will deform the runner gaskets, and cause you all sorts of tuning issues, such as you have here. Hit each intake bolt slow and easy and make 4-5 passes, each time sneaking up on final torque value. Take your time. Have another look at plugs again also, just to see if what you’re thinking is correct. A vacuum leak will cause the car to over fuel, and your plugs will look pig rich again…when in reality it’s not rich at all. Nic is a great guy with a lot of knowledge. Call him and pick his brain also.
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
I already covered all that. There’s no vacuum leak. I put the intake on nice and easy did everything as I should torqued to spec re checked all that sprayed around no leaks. It doesn’t do this crap every time. I just went outside it’s started right up. Seems like it changes every time I shut it off and re start it. There’s times when I start it thing does a quick bog then rev. I shut it off re start it instant rev. When it’s like that it runs fine on the road.
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
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
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
So freaking sick of this dang car I don’t get it. This morning I went out it fired right up let it run for a minute shut it off fired right back up. Let it sit till the afternoon tried starting it wouldn’t start until I gave it gas. Drove 5 minutes down the road did the usual sputter or miss between the gears. Stopped at ace hardware for a couple bolts go outside car wouldn’t start until I gave it gas. Pulled next door to the market grabbed something inside came out fired right up this time and ran perfect back home no sputter. I don’t get it.
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
I have not done that. I’ll check them. I have the racetronix harness on the pump. I’ll check the wiring again. What are the chances my 98 pcm is crapping out?
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
Swapped the ignition relay with another and same with fuel pump one. Started it still did the same crap. Just pulled my fuel pump everything looks fine. I might swap back to my first racetronix pump and see what it does. This is my 3rd pump still ran the same with the others. But I didn’t have the intake out and fixed when I tried those.
Staging Lane
Joined: Jul 2014
Posts: 53
Likes: 7
From: London
$50. Final offer.
I shared your frustation chasing a fault for 3 months on my truck.
Only advice I can give is check the loom, test the sensors and write down what you have tested and the results so you can see what/if anything has changed.
I had an intermitant fault that meant sometimes it would start first time and others would crank, backfire and wouldnt run unless I modulated the throttle pedal. Turned out that particular fault was the 12v to the cam sensor had a break in it and was making contact intermittently. Fixed that and one iof the multiple problems was fixed!
Keep at it - you have this.
Paul
I shared your frustation chasing a fault for 3 months on my truck.
Only advice I can give is check the loom, test the sensors and write down what you have tested and the results so you can see what/if anything has changed.
I had an intermitant fault that meant sometimes it would start first time and others would crank, backfire and wouldnt run unless I modulated the throttle pedal. Turned out that particular fault was the 12v to the cam sensor had a break in it and was making contact intermittently. Fixed that and one iof the multiple problems was fixed!
Keep at it - you have this.
Paul
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
$50. Final offer.
I shared your frustation chasing a fault for 3 months on my truck.
Only advice I can give is check the loom, test the sensors and write down what you have tested and the results so you can see what/if anything has changed.
I had an intermitant fault that meant sometimes it would start first time and others would crank, backfire and wouldnt run unless I modulated the throttle pedal. Turned out that particular fault was the 12v to the cam sensor had a break in it and was making contact intermittently. Fixed that and one iof the multiple problems was fixed!
Keep at it - you have this.
Paul
I shared your frustation chasing a fault for 3 months on my truck.
Only advice I can give is check the loom, test the sensors and write down what you have tested and the results so you can see what/if anything has changed.
I had an intermitant fault that meant sometimes it would start first time and others would crank, backfire and wouldnt run unless I modulated the throttle pedal. Turned out that particular fault was the 12v to the cam sensor had a break in it and was making contact intermittently. Fixed that and one iof the multiple problems was fixed!
Keep at it - you have this.
Paul
Staging Lane
Joined: Jul 2014
Posts: 53
Likes: 7
From: London
Might be a long shot but have you got access to a Noid light?
I am grasping here but could it be the injectors not geting a clean signal casuing the problem you have described?
I would start by checking the voltage to the injectors and then plug the noid light into the injector plug in turn and seeing if they all flash with the same intensity.
Intermitant faults are the worse.
Paul
I am grasping here but could it be the injectors not geting a clean signal casuing the problem you have described?
I would start by checking the voltage to the injectors and then plug the noid light into the injector plug in turn and seeing if they all flash with the same intensity.
Intermitant faults are the worse.
Paul
Thread Starter
On The Tree
Joined: Nov 2021
Posts: 138
Likes: 15
Might be a long shot but have you got access to a Noid light?
I am grasping here but could it be the injectors not geting a clean signal casuing the problem you have described?
I would start by checking the voltage to the injectors and then plug the noid light into the injector plug in turn and seeing if they all flash with the same intensity.
Intermitant faults are the worse.
Paul
I am grasping here but could it be the injectors not geting a clean signal casuing the problem you have described?
I would start by checking the voltage to the injectors and then plug the noid light into the injector plug in turn and seeing if they all flash with the same intensity.
Intermitant faults are the worse.
Paul
Rain makes it worse? You’ve got something…a wire or a sensor…with a crack or a tiny hole on it. I had a cracked plug wire once that drove me nuts…in the rain it would break up and sputter. The silicone draws moisture, and when it was raining the thing would sputter like crazy under load.