My engine developed a shake/misfire in the middle of a drive

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magnumdust

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So today i took my car out for a drive and it seemed to run fine for the first 10 miles. Then i slowed down from the 55mph area to a 25mph zone and the car began idling rough, shaking very badly(think everything rattling/chattering), and the car had no power.

I got to my friends place, checked to see if a spark plug wire came loose. Everything seemed fine and I babied the car home. I started it in my driveway 10 minutes ago and it shakes and sounds like its running on 6 cylinders.

Timing is 14 initial, 32 total
Running a self-tuning efi.

Any ideas?
 
Fuel pump could be on its way out...starving for fuel.Easy to check,just disconnect fuel line and crank over....into a jug ofcoarse.
 
What color is the exhaust?

Have you pulled any plugs and checked to see if they are fouled or gas soaked etc...


If you take a jar and pour a little gas down the throttle with it wide open, and then start the car, does it run smoother at first, or rough all the way?


How old is your gas? Has your car been in storage?


Bent pushrod?
 
pettybludart said:
Fuel pump could be on its way out...starving for fuel.Easy to check,just disconnect fuel line and crank over....into a jug ofcoarse.
Click to expand...

I doubt its the fuel pump because this efi system doesnt like to run on less than 45psi. So i doubt the car would even idle of the pump was failing.
 
krazykuda said:
What color is the exhaust?

Have you pulled any plugs and checked to see if they are fouled or gas soaked etc...


If you take a jar and pour a little gas down the throttle with it wide open, and then start the car, does it run smoother at first, or rough all the way?


How old is your gas? Has your car been in storage?


Bent pushrod?
Click to expand...

As far as i can tell, no colored exhaust.

I haven't pulled plugs because the weather here turned south when i got home.

The gas is maybe 3 months old. The car was sitting because of a gas leak and i recently replaced the tank. The car ran fine two weeks ago when i took it out.

I'm gonna try to check the rockers/pushrods tomorrow if its not pouring rain.
 
Do you hear any engine noises, like lifter noise?? It might be a bent pushrod or two. Try to isolate it to one side, it could also be a bad injector????
 
I'd start with the last thing you did to the car and make sure nothing related to that has caused a problem.
Hard to give any other advice based on info
 
loosen the gas cap it might not be venting .that a perfect description of not venting. I had this problem with a duster with a closed system
 
Pull and read the plugs,,

If you don't see something obvious, and don't know how to read them,, post pix here..

hope it helps
 
Running EFI nvm. My guess is EFI is adjusting to cold weather.
 
Turned out to be something simple and annoying:



I guess those heat shields were no match for the hedman header tube that gets in the way of cylinders 5 and 7
 
You have to find a way to route them and keep them from touching the header.
 
Abodybomber said:
You found it, and it's cheap.Cool. Number 5,or number 7?
Click to expand...

Both, those hedman headers have killed at least 4 plug wires on those cylinders now.I definitely wont be putting these style of headers back on when they wear out. I'll step up to TTI's or whatever works best with an alterkation or HDK system.

krazykuda said:
You have to find a way to route them and keep them from touching the header.
Click to expand...

Right now the plan is to replace the wires, buy some black heat wrap and wrap that section(would do the whole header, but they're a pita to remove), and look into some valve cover mounted wire guides to hopefully direct those wires away from the the heat.
 
The headers are not the problem, poor plug wire routing and retention is. I use 135 degree custom/builder type Taylor plug wires and wire looms that bolt to valve cover bolts. Preferably the type that can squeeze the plug wires and not allow them to rotate after you have precisely arranged them for clearance.
I have only burnt plug wires when not loomed and spaced correctly. Yes I learned the same way as you have SEVERAL TIMES.
I am not trying to be a condescending butt munch, my apologies if taken so. I for what ever reason get extremely irrational and irritable when poor craftsmanship is exercised in routing plug wires, fuel lines and engine bay hose and wire routings. Many people think those fancy fifty dollar looms are a waste, yet two cheap plug wire sets will set you back forty to eighty bucks. I see them similar to brakes you just need them or its a wreck.
 
magnumdust said:
I guess those heat shields were no match for the hedman header tube that gets in the way of cylinders 5 an7
Click to expand...

If you aren't really too concerned about aesthetics, go to NAPA and buy a foot of their high heat silicone tubing. The stuff I bought is blue. Put a piece on the wires with the issue, 6 inches each should do it.

You can't burn it with a hot wrench, I tried. I have it on a couple of wires, and my starter wire as it was a bit too close for comfort.
 
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