Still popping!!!

[Lethal5Oh]

Ok im getting really pissed here. I just put in a new Walbro 110lph fuel pump and an Aeromotive AFPR in. Set the reg to 40psi, is this ok. I ran the car till it warmed up. These 2 things help to wake this car back up but after i got home and let it sit for 15 minutes or so i started it and its still popping. Its a continuous popping thru the hole rpm range. Whats going on with this thing? The only other real mod is a K&N air filter, everything else is stock. Fuel filters been replaced. My guess is the ignition module? It stops after being driven for a few minutes. it only happens when the temperature is above 85 degrees outside. I NEED HELP GUYS!!!!

P.S. i dont know if it will help diagnosis but it also cranks slower when its going to do this. Other times it cranks normally. thanks

[Hethj7]

Maybe it is a bad fuel injector ?

I am not sure since it seems to only happen under certain conditions. But, I had a popping problem once and found out one injector was bad, so the lean condition was causing the popping.

I would look for some other opinions though.

[Lethal5Oh]

Im kinda doubting its an injector because it goes away after i drive for a few minutes. Im thinking its either the coil, TFI module, or the "hall efect sensor" My original thinking was that since the fuel pressure was dropping to nothing after shutoff that it was the fuel vaporizing and causing a vapor lock or something of that nature. I guess the injector could be a posability as the 2nd owner had to replace a couple inectors. thanks

[Lethal5Oh]

Heres some more info. This morning i started the car after sitting all night and it had the continuous popping but it was very faint sounding. Drove the car about 2 miles, got in my driveway and it died. The car stuttered as if i let the clutch out to fast (which i didnt) when i first started it. I really need some help here guys. thanks

[Lethal5Oh]

ANY ONE?! wheres PKRWUD when you need him??

[sn95gt19]

mine pops a little when its cold, but within about 30sec. of driving it stops. i would check the simple things that need replacing anyways like- spark plugs, plug wires, and the notorious tfi module, o2's, i would start with plugs and wires though. the reason that i started modifying mine was that i must have floated a valve and it smacked the top of the piston and created a dead cylinder- that made some massive popping noises though. i dunno, good luck

[Lethal5Oh]

Ya im thinking of replacing the TFI and the wires and plugs. The car had a tune up about 1 year before i bought it with MSD wires. I found one to be barley hanging on to the spark plug and 2 of them were loose on the cap. im going to test the TFI module tommorow and the coil to. I was thinking the pickup coil might be going but i have to rule that out because it wouldnt run right after it got hot if it was bad. The car runs fine till i warm it up and the let it set. Also just in case theres any confusion, this popping is not after its been reved. It does it idleing or if i rev it. Thanks

[PKRWUD]

Originally posted by Lethal5Oh
ANY ONE?! wheres PKRWUD when you need him??

Sorry, I've been busy.

I don't remember what's been done, or where you're at, but based on what you've said in this thread, it's hard to tell. Most of the items that would cause this are more prone to failure when they get hot, not when they're cold. Does the popping follow a set rhythm, or is it random? Can you isolate a specific side that it's coming from (use a 3' piece of heater hose, and listen to the headers), or does it jump from side to side?

Also, does your fuel pressure still bleed down, or is it stable after turning the key off?

Take care,
~Chris

[PKRWUD]

Also, are wires #5 & #6 separated?

[RPM427]

try raising the PSI on the AFPR to 43. See if that helps.

[Lethal5Oh]

I havent listened to see if its from one side or the other. Fuel pressure drops to about 23PSI after shut down but its slow but steady drop. Its a steady popping. I tested the coil. Primary resistance is .9 ohms (according to Haynes manual this is ok.) Secondary is OPEN. Primary to case is OPEN. There was a good bit of corosion on the terminal of the coil (where the spark plug wire attaches) I cleaned that off before testing. I can see that there are some areas where some of the wires are crossing. Im not sure which ones but there are atleast 3 place on different sets of wires. Im going to order a kit from Performance Distributors that has a new coil, TFI modul, wires, cap and rotor. If this doesnt help i guess i start looking for other things. (after i get done pulling my hair out lol) The pickup coil would be my next guess. I plan to up the fuel pressure to around 45 when i get this ignitio kit. Thanks

[PKRWUD]

It would really help if you could identify which side the popping is coming from.

[Lethal5Oh]

Well now that the fuel pressure is where its supposed to be and the engines getting the fuel its supposed its realy running like SH**. The car feels like its gonna die and doesnt have that much power. When i shift i can hear popping from the tailpipes (this is cold too) If i stay in second to go around a corner then shift it really pops. FYI im running Amaco Premium gas if that makes a difference. I haven had time to really mess with listening to which side it is yet because i was cleaning my other car that im selling. My new coil and TFI module will be here thursday so ill see if that fixes it. I have time tommorow so ill try to see which side it is, but my guess just from the way its sounds in the garage or next to another car outside its both.

[bigblock]

Is it getting worse with the more fuel presser?
is there black smoke coming out of the back or a lot of black resdue on the tail pipes?

[Godslayer]

Have you checked the computer for codes?

[Lethal5Oh]

Checked the computer a few months ago but not recently. There werent any then. No check engine light yet. Theres always been alot of black crap in the pipes no black smoke that i can see.