Popping Exhaust, Loss of Power

Strype · Oct 28, 2010

93 Notch
5 Speed
66k
Gt40X heads
B303

Hey guys I recently did an HCI swap on my car. Finally got it running right by adding a 190lph fuel pump. After a 12 mile drive I put it up. When I took it out again a few days later it started sputtering and popping thru the exhaust, and losing power through every gear. It was so bad that I took it home.

* I found out the timing was set to 30, so I fixed that (now at 14).
* I redid the roller rockers and found one with too much shim

None of this fixed it. The car shakes bad at idle and every now and then it will try and cut out.

We looked last night and it seems the new Accel wires are arching all over the place near the headers. Can that be the issue? Why did it just start?

My truck got hailed on so in order to have it fixed I need to drive my mustang

List of parts:
190lph fuel pump
C&L MAF (for 19#)
Stock injectors (55 psi)
Accel coil
New plugs (gap checked)
Reman distributer
Newish TPS
New cap & rotor
Accel wires

And I'm running gt40x aluminum heads with a b303

Thanks doods,
Strype

94GTMustang5.0 · Oct 28, 2010

if your wires are arching all over the place, then yeah its gonna cause it to run bad cause your losing spark! try some electrical tape and move the wires away from the headers and see how it runs then.

Strype · Oct 28, 2010

94GTMustang5.0 said:
if your wires are arching all over the place, then yeah its gonna cause it to run bad cause your losing spark! try some electrical tape and move the wires away from the headers and see how it runs then.

Does that mean that these new wires are bad? I wanna say they're 8mm but I could be wrong. Replace them? Loom them?

Haus · Oct 28, 2010

do you have the correct firing order??

Strype · Oct 28, 2010

http://www.stangnet.com/mustang-forums/804629-not-running-right-popping-exhaust.html

This guy's same problem was crossed wires so I'm guessing they can cause issues... I'll tear it apart tonite- Thanks

Strype · Oct 28, 2010

Haus said:
do you have the correct firing order??

Yea that's the first thing my neighbor asked- I'm pretty sure I do but I'll check that as well tonight

HISSIN50 · Oct 28, 2010

If it still shakes at idle after new wires are installed, be sure the balancer didnt spin. That would also explain the timing appearing to be so far off.

Strype · Oct 28, 2010

HISSIN50 said:
If it still shakes at idle after new wires are installed, be sure the balancer didnt spin. That would also explain the timing appearing to be so far off.

Interesting... How would that happen? I mean me and a friend put it together so it's quite likely that anything could happen

You know... When I was first taking the top end apart, I noticed a lot of belt dust all over the place AND THE CAR WAS DOING THIS POPPING BIT BEFORE WE BUILT IT.

It was a couple of years ago so I had forgotten.

HISSIN50 · Oct 28, 2010

The balancer is two pieces which are bonded with an elastomer. When the elastomer starts to let go, it can let the outer ring rotate or start to move longitudinally.

Strype · Oct 28, 2010

You maybe right but I'm not gonna jump to conclusions just yet. I'm ordering some Taylor 8mm wires right now. My buddy had this exact problem on his 347 stroker and those Taylor wires fixed it.

SPEEDYLIFSAVR · Oct 30, 2010

I had a similar problem when I did my HCI . I just "clocked"my MAF meter to about the 1 o'clock position from straight up and problem solved . Try if all else fails .

Strype · Oct 30, 2010

???

How do you do that?

mycaptainchris · Oct 31, 2010

If you've just changed the fuel pump I'd suggest the issue maybe fuel related?
Maybe seriously rich or very lean?

Strype · Oct 31, 2010

Well I checked the pressure and I'm running 55psi but I'm running the stock 19lb injectors. I need to put the 24lb injectors on so I can knock it back down but I'm waiting on the Taylor Wires to get here first.

jrichker · Oct 31, 2010

Do you have a aftermarket MAF or custom tune calibrated to match the 24 lb injectors?

Strype · Nov 2, 2010

jrichker said:
Do you have a aftermarket MAF or custom tune calibrated to match the 24 lb injectors?

Yes sir I have both the C&L 19lb and 24lb sizes. Currently the 19lb MAF tube is in there because I have the stock injectors in it. I may drop that fuel pressure back down tonight and try it. It is DEFINATELY LOADING and then popping. I just don't know from what.

The car was running great and just started doing this one day.

PS: The WIRES didn't fix it. I ordered Taylor wires and it's still a light show at night near the plugs. I'll try plugs next.

HISSIN50 · Nov 2, 2010

SPEEDYLIFSAVR said:
I had a similar problem when I did my HCI . I just "clocked"my MAF meter to about the 1 o'clock position from straight up and problem solved . Try if all else fails .

Strype said:
???

How do you do that?

Rotate the MAF (which moves the location of the orifice inside the MAF).

Strype · Nov 3, 2010

HISSIN50 said:
Rotate the MAF (which moves the location of the orifice inside the MAF).

Thanks guys I'll try that. I'm also going to drop that fuel pressure back down a bit and see if that helps. What still weirds me out is that the spark plugs can be seen firing in the dark, I'm guessing I need to buy another set of plugs as well. I may have run too much fuel to them.

HISSIN50 · Nov 3, 2010

Or find a way to further insulate the plug wires.

Strype · Nov 6, 2010

Checked the following...

Plug wires
Timing
Fuel Pressure
Roller Rockers

Still knocking and popping.

I'm putting the stock rockers back on. If it still gives me problems that will narrow it down. I can use the stock rockers on pedistal GT40X heads right?

Popping Exhaust, Loss of Power

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