I’m out of ideas now. Random misfire, hard start.

[Dlipp_]

Still trying to get some insight on this, when I feel like I’ve narrowed it down, I’m just back to square one. Sorry for the long post.

Did a lt4 hot cam, not sure if that will cause the misfire, tuned ecm from black bear for it.

97 5.7l , random misfire, shakes every few seconds or so at idle. First start of the day it fires right up, will crank and crank and crank unless I crack the throttle just a little bit any start after that. Even 3 seconds of running on the first start of the day.

Through the forums, speed shops, my own diagnosis I’ve replaced within the past couple weeks

Accel Distributor
Ignition control module
Coil
Plugs
Wires
3 different Ac Delco Caps
Fuel filter
Delphi Fuel pump
Standard motor parts upgraded Spider injection
MAP sensor
MAF sensor
Both upstream o2 sensors
EGR is deleted with the tune
New Crank sensor
Coolant temp sensor and the pigtail

With the cam I did the ls6 springs, retainers, keepers, new lifters, new pushrods, cloyes timing set

Now this is where I’m stuck at, when i unplug the MAP sensor truck fires right up no problem. I sprayed everything I could up top with brakleen for vacuum leaks, no difference in idle.
It’s showing misfires on every cylinder except 8. 2 the most, plug looks fine.

 

[Hipster]

Unequivocably, without a doubt, Is it installed correctly without a reasonable doubt that it is out of phase, no doubt many clowns will argue it doesn't matter...... but it does, "out of phase can lead to carbon tracking, missfires etc. Desctibe the process you used to do distibutor install. Needed to be tdc #1 COMPRESSION stroke not tdc exhaust without doubt. Where the rotor should be facing to be in proper phase is detailed ib the FSM. What did or didn't you do?

 

[454cid]

You would be better off continuing with one of the other threads you've started about this problem/engine, instead of making a new one.

 

[Dlipp_]

You would be better off continuing with one of the other threads you've started about this problem/engine, instead of making a new one.

I would if anyone would give insight, so I’ll make a new one until someone does lol, from what I’ve gathered, no one does

 

[Dlipp_]

Unequivocably, without a doubt, Is it installed correctly without a reasonable doubt that it is out of phase, no doubt many clowns will argue it doesn't matter...... but it does, "out of phase can lead to carbon tracking, missfires etc. Desctibe the process you used to do distibutor install. Needed to be tdc #1 COMPRESSION stroke not tdc exhaust without doubt. Where the rotor should be facing to be in proper phase is detailed ib the FSM. What did or didn't you do?

I did the distributor after this all was happening, same thing still happening. Cam retard is at 0. Distributor TDC, compression stroke, pointing at #1 cyl.

 

[fancyTBI]

I would if anyone would give insight, so I’ll make a new one until someone does lol, from what I’ve gathered, no one does

That’s a sure fire way to get zero help.

 

[Dlipp_]

That’s a sure fire way to get zero help.

Is what it is I guess

 

[scott2093]

Is what it is I guess

I know it can be frustrating waiting for some kind of help when trying to get things going.
Where were you when I was asking about why I couldn't get my lifter plunger unstuck?lol

Could always use chat gpt as a replacement if wanting an instant answer but I'm not sure that's going to be better than what you could come up with yourself either by reading or turning wrenches and seeing what happens...

I found, through the help of others either directly or indirectly, that if you use your thread as a notebook of sorts, you can keep posting your progress or what you've tried. What worked for you or didn't, and you'll have a notebook that you can reference as you move through your task. Maybe continuing your old thread could be looked at as similar advice..

Try to think of it that way, and if anyone happens to have an answer they "know" will be useful or productive for you and jumps in, all the better.

I'm not going to be of any help. So you are a pioneer to me and one day if I ever buy the same year truck...with a tune?... , who knows, maybe I'll need to visit this thread...

Good luck!

 

[Dlipp_]

I know it can be frustrating waiting for some kind of help when trying to get things going.
Where were you when I was asking about why I couldn't get my lifter plunger unstuck?lol

Could always use chat gpt as a replacement if wanting an instant answer but I'm not sure that's going to be better than what you could come up with yourself either by reading or turning wrenches and seeing what happens...

I found, through the help of others either directly or indirectly, that if you use your thread as a notebook of sorts, you can keep posting your progress or what you've tried. What worked for you or didn't, and you'll have a notebook that you can reference as you move through your task. Maybe continuing your old thread could be looked at as similar advice..

Try to think of it that way, and if anyone happens to have an answer they "know" will be useful or productive for you and jumps in, all the better.

I'm not going to be of any help. So you are a pioneer to me and one day if I ever buy the same year truck...with a tune?... , who knows, maybe I'll need to visit this thread...

Good luck!

Great input, just didn’t want my thread to get lost in the abyss, so I made new ones, idk why people get mad at new threads, we’re all mostly here for the same reason.

 

[454cid]

Great input, just didn’t want my thread to get lost in the abyss, so I made new ones, idk why people get mad at new threads, we’re all mostly here for the same reason.

Because it's messy, and fragments any information you or others post. It also could be taken to falsely boost your post count to gain access to hidden areas, or to look more legit for spamming purposes. It's also looks like you're demanding our attention.