miss at slow acceleration and cruise

[drewdude92]

My truck has a little miss when accelerating normal and at cruise going thirty forty fifty and seventy just whatever. It runs perfect idling and laying it to the floor. Ive looked at my plug wires when it is dark outside and can see a tiny glow coming from plug wires 2, 3, 4, and 7. I replaced the plug wires with others just to see and its still i small glow. I dont know whats going on for sure. Also if your getting up to speeds very slowly sometimes it will backfire. it sounds like its coming through the carb.

any help would be awesome. thank you

[Security guy]

Just get a toyota gas pedal installed and that will fix it all. Just kidding, not for sure but it could be timing is off a little or carb may need some adjusting. Is all your vacuum lines hooked up corectly or open ports blocked off some how? You shouldn't be getting any glow from wires. Did you replace them with new wires or some used ones? Try siwcthing wires around if you have used ones to see if the glow changes as well. ??

[drewdude92]

yeah my plan for today is spray carb cleaner over intake to check for vacuum leaks... i didnt switch a plug wire that i knew wasnt glowing with one that is glowing. ill try that. so im still stuck with timing, vacuum leak, or wires. thats prob all ill get with out someone actually looking at it.

[BLK96]

I had an issue with a miss only during light accel or cruise, turned out to be a bad reman distributor. Would only occur during vacuum advance operation, didn't happen with idle or heavy throttle where there was no vac advance. Doesn't explain your wires. Good luck.

[gonzo6869]

Its hard to tell by your avatar, but do you have headers? If you do, make sure the wires are not touching them. I had a similar problem, turned out to be burnt wires ( they did not glow), also the plugs for # 5 & 7 cylinders where backing out. Check all your plugs and make sure they are tight.

[petey-pablo]

Originally Posted by drewdude92

yeah my plan for today is spray carb cleaner over intake to check for vacuum leaks... i didnt switch a plug wire that i knew wasnt glowing with one that is glowing. ill try that. so im still stuck with timing, vacuum leak, or wires. thats prob all ill get with out someone actually looking at it.

Quick question How does Carb cleaner work for checking vacuum leaks isn't it flammable?

A miss at slow acceleration,timing would be my guess, I was driving around like that for a while found out my distributor tie down bolt was loose so timming was off fixed it now no back fire..

[cdowns]

sounds like a vaccume leak/ timing /or running very lean

carb cleaner will cause motor to speed up if it's sucked in thru a vaccume leak// check condition of sparkplugs theres charts in service manuals that will help you "read" the spark plugs

[drewdude92]

alrighty ill try to advance my timing just a tad more. I advanced it a little yesterday and it made the problem a little better. But if i did it anymore it would diesel on when i kill it. so idk whats going on for sure. Im gonna buy new taylors then mess with the timing a little more

[petey-pablo]

Originally Posted by cdowns

sounds like a vaccume leak/ timing /or running very lean

carb cleaner will cause motor to speed up if it's sucked in thru a vaccume leak// check condition of sparkplugs theres charts in service manuals that will help you "read" the spark plugs

Cool I did not know that, it's nice to learn something new Thanks....

[D-Rat]

Please post up what you find out. I've been chasing this for a while now. Feels almost like someone is lightly tapping the brakes when I'm at a steady speed and I'm getting the backfire occasionally too.

[Security guy]

D-Rat, how old is your motor? I haven't had this happen before, but is your timing chain old enough to strech causing the timing to jump around? Just thought I would throw this out there.

[drewdude92]

yeah thats kinda what mine is like also. i advanced it a tiny bit more and got it running better still. gonna advance a tiny more tomorrow then tighten my distributor clamp down for good!

[Jacfourteen]

What carb are you running? I have a holley 670 street avenger that was still at stock jetting, and it did the same think + some bucking with light acceleration. I did some research and found that they are jetted really lean from the factory, so I upped the jets some today (found some good starting recommendations online) and that made a huge difference. I just got back from some test cruising and I had a smile plastered on my face! Not only did it fix the bucking and missing, but it made the top end pull alot harder (4000+ rpm). Good luck tuning yours.

[D-Rat]

Originally Posted by Security guy

D-Rat, how old is your motor? I haven't had this happen before, but is your timing chain old enough to strech causing the timing to jump around? Just thought I would throw this out there.

It was a complete rebuild only 12k miles ago.

[50mercfan]

Are you running an HEI distributor? If so make sure your plug gap is correct. I set mine at .045. Also, make sure your plug wires are crossed and not running parallel to each other. I the wires are running side by side they can jump spark to each other.

[drewdude92]

I got my timing set about right now. Still got bout three plug wires glowing right at the spark plug. Im ordering some new taylors here soon.

[gonzo6869]

Have you checked to see if the wires that are glowing are burnt. If you have headers that is a common problem. When you get your new wires, make sure they kept as far away from your headers, if you have headers that is.

Hope the new wires will fix your problem.

[Jacfourteen]

Originally Posted by gonzo6869

Have you checked to see if the wires that are glowing are burnt. If you have headers that is a common problem. When you get your new wires, make sure they kept as far away from your headers, if you have headers that is.

Hope the new wires will fix your problem.

They also have header spark plugs that are a little shorter to help out with header clearance too. I think they are made by accel.

[1969K10]

have you checked your timing chain for stretch? put a light on it, and see if it's steady, or bounces around a little.

[drewdude92]

yeah me too im gonna get the taylors that say are made for headers. and it couldnt be my timing chain since it has a gear drive haha

[Sinister]

I think you need to tune your carb.

[drewdude92]

I put new plug wires on and still getting a little glow from cylinders numbers 2,3,4,and 7
Im gonna replace the plugs now. They were brand new when i started having this problem. Is there a chance that someone could have dropped the spark plugs and messed up the porcelein or something?

[longhorn396]

i am having the same problem

[drewdude92]

well ill let you know if i figure it out and you let me know im doing the plugs either today or tomorrow

[drewdude92]

changed the plugs and still the same problem. is there any way it could be the carburetor? When adjusting the two screws on the front of an edelbrock the motor should want to die when screwed all the way in right?