rotarhead0803

i have a 1984 Mazda rx7 gsl fb and I've had it for about a year now I am not sure what is causing the problem but the problem is that it will start mostly fine has a hard time on cold days and when it's wet out and during warm up sometimes it will just randomly die or it misfires and sounds like only one cylinder is firing, once it's warm it's completely fine though, when I drive it it will run great I don't hammer the throttle or anything just cruising and it cuts out and doesn't want to go like there's a rev limiter at lower rpms, then it dies and doesn't want to start for a while I'll let it sit and then it goes back to normal and repeats this process it has gotten worse and worse through the time I have had it though, not sure if it's fuel, ignition or timing related,

KansasCityREPU

iTrader: (9)

Sounds like a bad rotor cap or plugs wires. I'd change out the rotor, cap, rotor bug, plugs, and wires.

rotarhead0803

I already changed the rotor cap cap and rotor and just got new plugs yesterday still the same wires though didn't replace those, they seemed to spark fine when I tested them

miasmicmonky

iTrader: (1)

I would also check your fuel bowls front and back. My car seems to be losing fuel from the fuel bowls overnight causing some starting issues and issues running for the first minute or two.

Replace ignition coils, cap and rotor, plug wires, plugs.

Replace your fuel filter and flow test the fuel pump. test your OMP or just start putting in 2 stroke (the preferred option) What kind of mileage is on this motor?

Drive it hard for a few days. There could be some carbon build up which in my experience is more obvious cold than warm. To combat this, I tend to get mine on the freeway in 3rd at 65 mph for a good 2 or 3 minutes. The car always feels more alive and peppy after this. At least if it hasn't been on a fun trip in a while.

t_g_farrell

iTrader: (1)

I think its your ignition. Possibly the ignitors are going out.

First rule out all the simple stuff:

1. Make sure theres no vacuum leaks
2. Make sure the fuel delivery is working correctly, test flow, pressure and replace fuel filter.
3. You already did the cap/rotor and plugs, so good start.

The FSM has a procedure in it for testing the ignitors. The problem is that the ignitors sometimes only fail as they get warm. So it will start and run fine for some time. Then it will
die and won't restart until it cools down. When this starts, it will be annoying and not very
often, but then it will start happening quicker and more frequently until it just can't drive
anywhere for very long. Part of your description leads me to think you have an ignitor issue.

It could be just the leading, so you could swap them and see if it works better.

GSLSEforme

From your description of the problem i believe it's ignition related also,when you say it acts up when it's wet out leads me to think ignition wire insulation breakdown. You say you've replaced cap.rotor,plugs already and problem persists. I suggest replacing plug/coil wires, NGK wires are $15 dollars. Not a big expense and completes the last link in ignition system. Look closely at coil towers for signs of carbon tracking. Before replacing wires may want to try misting wires,cap,coils with a spray bottle(after dark works best) and run car,accelerating engine to load ignition system and look for a light show to confirm this to be the source of problem. Personally would just go ahead and replace wires for minimum investment of time/money and test drive for results....do the simple,least expensive things first. GL

miasmicmonky

iTrader: (1)

For the price, Just replace the wires!

rotarhead0803

Thank you guys for all of the replies I will now start going through all the possibilities and see where I get from there I will update or post again if I can't seem to find any solution

QUOTE=GSLSEforme;12154403]From your description of the problem i believe it's ignition related also,when you say it acts up when it's wet out leads me to think ignition wire insulation breakdown. You say you've replaced cap.rotor,plugs already and problem persists. I suggest replacing plug/coil wires, NGK wires are $15 dollars. Not a big expense and completes the last link in ignition system. Look closely at coil towers for signs of carbon tracking. Before replacing wires may want to try misting
wires,cap,coils with a spray bottle(after dark works best) and run car,accelerating engine to load ignition system and look for a light show to confirm this to be the source of problem. Personally would just go ahead and replace wires for minimum investment of time/money and test drive for results....do the simple,least expensive things first. GL[/QUOTE]

TheRX7Project

iTrader: (3)

Did you replace the coils? Especially with you mentioning issues when it's damp, sometimes a hairline crack or carbon on the coil can cause the issues you talk about.

TimWilbers

iTrader: (1)

To the OP.
See if this thread sounds similar.

https://www.rx7club.com/1st-generati...ssues-1099050/

I went through igniter issues last year.
If the leading goes out you loose most power but it will still go on the trailing.
If the trailing goes out so does your fuel pump.

I had two intermittent and finally both failed completely.