Engine Cutting Out Randomly

[Shift_Alabama]

Okay guys I really need some help with this. For awhile now (almost three months) my car will randomly cut out or stutter, I dunno what to call it. It happens mostly when I have it in 5th at 1800rpm or lower and give it a little gas, or when I try to accelerate after turning without putting it in first gear. It also randomly happens when I'm at wide open throttle. Any help would be greatly appreciated.

 

[Jrgunn5150]

So under heavy load it dies?

 

[quickstang_1994]

You dont have enough power to move the car so it loads up with fuel you need to shift at higher rpms or add some gears. mine does the something down low

 

[Jrgunn5150]

I have to agree, that's the only thing that makes sense. Modulars really don't like ot be lugged down, even NPI one's.

 

[Shift_Alabama]

But there has to be something wrong. It isn't a minor sputtering, it shakes the whole car and it mainly happens in low RPMs, even though I shift at 2500RPM in normal traffic. There wasn't anything wrong with it until my dad and I dropped the fuel tank to replace the fuel filler neck gasket. I was thinking that maybe the fuel filter might be stopped up or need replacing. Thanks for the replies guys.

 

[Jrgunn5150]

Mybe you knocked some poo loose in the tank and the pump can't keep up? What do your plugs look like?

 

[Shift_Alabama]

They guy I bought the car from four months ago said it had new plugs, but I'm not so sure now. Fouled spark plugs could be doing this?

 

[Shift_Alabama]

I found this on modded mustangs when I was searching for a rebuild kit for my tranny but it seems to describe exactly what's going on in my car, but there isn't a solution listed:
http://www.moddedmustangs.com/forums/tranny-trouble-vt36173.html?highlight=transmission+rebuild

 

[Jrgunn5150]

Well the additional info narrows it right down to the fuel systems, since you dropped the tank, then it started. Which means a reading of the plug's in in order.

 

[Shift_Alabama]

I was wondering if it has something to do with my blown-out exhaust system, since the guy on modded mustangs seemed to be running rich or something from his error codes. There isn't much of my exhaust left because of all the holes in it...

 

[Jrgunn5150]

You 02
s could be faulty if they are water damaged, but they usually trip the engine light.

 

[Shift_Alabama]

That's what I was thinking too. My check engine light isn't on and never has been, so that really confuses me.

Just to be sure, let me make a list of possible things:
Fuel pump
Fuel filter
Fouled spark plugs
Stopped up injector
Faulty 02 sensor

Anything else I missed?

 

[Jrgunn5150]

Less likey, but Idle Air Control, faulty TPS, and gummed up throttle body also.

 

[Shift_Alabama]

What exactly is the Idle Air Control? And how could that screw up my car?

 

[Jrgunn5150]

It's basically your choke, it's facing you when you look at the front of the throttle body from in front of the car, with a plug sticking out of it.

 

[Shift_Alabama]

Oh ok. Actually I think that could have alot to do with it, because sometimes the car idles really high (about 1700RPM) and alot of the time it doesn't want to idle back down with I put it in neutral. I'm gonna clean out my throttle body when I get time and see if that does any good before I get into the more complicated stuff...

by the way thanks for all the help man!

 

[Jrgunn5150]

No problem man, let us know what it turns out to be.

 

[Purple97GT]

I went through a similar episode chasing this same type of problem for years, and lost a motor on nitrous because of it.

This is what happened.

I was swapped to a 5 speed from an auto, installed nitrous, and installed a new Walbro 190lph intank fuel pump at the same time to make it to the WFC at Route66. I was tired from working 12-15hrs a day and working on my car for hours, taking a nap and going back to work, so I made a big mistake.

I went inside to take a nap between the fuel pump install. I stuck the fuel pump in the tank and barely turned the lock ring to keep dirt and stuff out. I was going to put it all back together after the nap. But when I woke up, I forgot about the lock ring not being turned all the way and bolted it back up.

For a long time I had a stumble, miss, jerk, loss of power, hesitation - whatever of those you want to call it and part throttle lugging around and even at WOT. I thought I had it fixed once and ran the nitrous only to blow the motor when it went lean. I thought this was from my LT's having the O2 sensor far away, I thought I had bad ignition problem, a short, you name it and I chased my tail trying to find and fix it!

Long story short, after the PI swap I still had the problem. I was pissed off bad. Then one day I was driving with the windows down with my g/f and kept smelling raw fuel. My next off day I started sniffing around the car with motor on and off. I smelled gas real strong around the tank, so I unbolted the SOB and could see where the fuel had been sloshing out of the half locked down ring that holds the fuel pump in. I cleaned it up, locked it down, bolted it back up and the car has run great ever since.

So my thinking is when you dropped your tank, you either left the filler neck loose, knocked a vacuum line loose, or something causing a vacuum leak at the fuel tank. Take it all back apart and recheck everything. Think about it, you never had the problem until you dropped the tank to work on it.

I only wish I had been smart enough to go back and drop my tank back when my problems started. I would've had time to build a badass PI instead of rushing to stick a stock PI in to geet my car back on the road.

 

[Shift_Alabama]

Wow that does sound like what it could be. How would I know if the filler neck is completely in there? My dad and I both checked the filler neck to make sure that it was in there, but I don't know anything about vacuum lines. What are they? Fuel lines? How can I check them? :dunno:

 

[Jrgunn5150]

There are some vacuum and vent lines running out of the tank, one of them exits through the bottom of the bumper cover on the passenger side, they look pretty much like fuel lines.