spoolin4life

I meant to say loose wire. I'm half asleep here lol. Although this stuff is not my expertise by any means. I have done a compression test and the engine is almost 180psi across all cylinders except #3 which is 168ish. So it should be strong. The spark looked very intermittent to me. Whenever I've tested spark in the past it's a very loud snap and never misses like it did in that video. Also there's no audible change on some of the cylinders when I pull their wires. The ignition system is pretty much all new components aside the rotor which was done last year. I appreciate the help all the same.

Same colors? I don't wanna burn the coil or start a fire haha. Thanks though

I actually have two 280zx distributors I tried it on with 2 modules and I had the exact same misfires on the same cylinders. So it has to be a ground somewhere not sending the proper output to the coil. I'm not sure the coil will work well with the resistor mind you. That's why I'm curious. I'm getting spark it's just very weak. Oddly though the module must prioritize cylinders 3 and 6 as they fire back to back in sequence and they're the strongest 20210806_173048.mp4

Are you absolutely sure they can be connected? I can't find a wiring diagram to confirm their outputs and such.

Hey folks, So I'm trying to sort out a multiple cylinder idle misfire on my 73 240z. I've replaced everything in my ignition system. (Coil, plugs, wires, distributor, distributor cap, ignition module, rotor) the problem still persists. I did a spark test and I have a weak spark across 4 cylinders. 3 and 6 are best but still even weak. I'm on a msd blaster 2 ignition coil with a 280zx distributor. I've deduced that either I have a lose ground somewhere or the ballast resistor needs to be removed to use the coil I have optimally at 12v. I still have the same problem with the old coil as well. So I'm curious and tried to find the answer online but on my ballast resistor I have 2 wires. One is black and white, the other is green and white (although the white on both looks yellowish). Can I connect them or do I need to connect them to somewhere else? Thanks for the help. I've read the writeups online and none seem to match my current coloring

I have not. I feel it could be the volume as the triples need volume but not pressure as you said.

I may just go the electric route with a fpr I have another mechanical pump I'll most likely swap to to see if that makes a difference but the sure bet is an electric if the mech. pump can't keep the supply up.

The carbs are getting roughly 3.5psi each. I found out my return line was closed and when I went to open it the car wouldn't even run properly at all - made the car run even worse than before. I feel like like you don't need a return line with the dhla 40s. I don't have a fpr. Just the stock mechanical pump. Do you run a return line?

I don't know, my car only has the mechanical pump from the factory, so my pressure is regulated by an Aeromotive FPR. I have just the stock mechanical pump but I'm assuming it's the top screw. I'll have to try playing with it when I put a fuel pressure gauge in line. Is there a chance it's something vacuum related that could cause this?

That is the logic I deduced as well. If the floats aren't allowing fuel into the bowl after a heavy throttle pull then there's nothing continuously going in. So amateur question, is the top screw on the fuel pump how you adjust fuel pressure?

Ya I don't wanna wash the cylinders out. I don't think the wideband is faulty, it's roughly a year old and I bought it used. I mean I have a spare i could try installing. But when I did an oil change on the old engine it did reek on fuel so I know the wideband is correct on that end and when it went super lean yesterday that's when it misfired during driving so it seems accurate. The sensor bung is located roughly 2 feet back from where the pipes merge from the stock exhaust manifold. Maybe it's to far down? But it shouldn't be doing this when I have the mixture screws turned 2.5 turns out. And yes it stayed at 22 at idle speed for quite some time after the one WOT pull to 4000rpm. That's when it experienced the misfire. Ya very confusing. I'll have to check my fuel pressure as well.

So if I'm driving around just cruising it's very rich at 8-9ish. But if I go WOT to 4500rpm I'm still rich at 9ish. I haven't pushed the car passed 5000 rpms ever. But as soon as I let off the gas the afrs go to 22 and stay there for a while (yesterday was well over 15 seconds at 22) until it starts misfiring. That's when I noticed the misfire again on the new engine. Luckily it went away when I richened the mixture screws and I don't think it harmed anything. Even when I rev the car briefly it goes pig rich and when I let off the throttle it'll go super lean for 6-7 seconds. That's far too long even for efi. My guess at this point would be sticky floats. I wish I knew more about these cars and how side drafts work ?

Hey Jon refer to my recent reply. Maybe you know what it's not getting fuel. Scared the heck out of me. New engine started misfiring but then did a compression test and it was 150psi across the board

I pulled that engine. Bottom end was fine. Valves were burnt ? but I think I know the issue. My car is going super lean after a pull. Runs super rich during cruising and during a pull. But as soon as I lean it out even a bit and then do a quick pull it spikes lean to 22 and stays there for a good 12 seconds. I guess it runs super lean and then burns the valves from being too hot. Almost did the same thing to the engine I just put in today. Any idea what would cause it to starve for fuel after a pull?

I did a couple tests wide open and no throttle at all. Numbers were roughly 110, 90, 110, 120, 120 and 130. We compressed some air into the cylinders and the bottom end seems solid still. I'm guessing valve issues still. And oddly enough the driver side seemed slack and the passenger was tight. My car is lhd