Popping at higher RPMs (from old board)

[Boost-It]

I posted this from the old boards, but figured I'd repost it. Anyways the car is running at 30 psi of fuel pressure and maybe the timing went way down when I reset the computer, this is the only time I noticed this now that I remembered. Does timing get reset when the computer is reset?

Here's the previous post incase anyone has any other solutions.

First, the car

88 5.0 bored .020 over, speed pro forged pistons, stage III ported E7 heads, milled and under cut for 1.94/1.60 manley valves, E303 cam yada yada yada


The Problem:

Just last night I was messing with the air adjuster that is hooked up to my Mass Air flow sensor (just bought the car last week), and finally got it to idle good (well 90% of the time), it was running too much fuel, not enough air. Anyways when I gave her today it started making popping noises at around 5000-5500 RPMs, maybe just 2-3 pops but I didn't like the sound of it. Timing is set at 26, I bumped the timing down to 24 once but the car seemed a helluva a lot slower when I did that a few days ago.

When I bought the car it was running 110 octane fuel, now that all that fuel is burnt off I'm running 93 octane. Would air in the exhaust cause this as well? I know there is a small leak in the H pipe but I dunno.




Also:

What exactly causes surging? The car seems to do it a lot more when I reset the computer, and I think the plugs and wires might need to be swapped out. Is there any other causes of surging?

[Boost-It]

The timing will not reset with the computer. Are you checking the timing with the SPOUT in or out? Pull it out, set timing to about 13-14, put it back in, try it that way.


What size injectors are you running? Fuel Pressure sounds awfully low too depending on which injector.

I'm running 30 lb injectors and 195 ph fuel pump. the 30 psi is with the vacuum line in.

By surging I meant bucking, like it'll jolt around a lot when i'm just light on the gas.

[Boost-It]

Ok timing was set back to 14 degrees, its still popping and my mechanic thinks it is the plug and plug wires. The wires actually zapped him when he went to go touch the boot on the bank that is popping. Hopefully this is the case. Just picked up some ford racing 9mm spiral-core wires and autolite plugs to put in tonight. The wires that are on there are solid core which the accel box urges not to use.

Anyways, he said otherwise its probably a sticky valve.

[jdsgallops]

surging is usually a sign of leanness. 110 race fuel if it was leaded could have messed up the o2 sensors. i would suspect the owner had the 110 in there to cover up the problem. race fuel burns slower thus it would tolerate more timing less/fuel with out showing the problem.

[Boost-It]

Turns out the popping was just preignition. I had some very bad plug wires that actually zapped me when i tried touching the boot. Replaced with some ford 9mm spiral core wires and she runs better than ever. No bucking, no preignition, nothing. I'm happy now :) Now it's time for an alternator, haha.