jshiz

iTrader: (4)

The car is a bone stock 1980 (later model that uses a distributor)

Alright. Since I had this car, i dropped the gas tank and made sure the lines and tank was clean. I got the carb rebuilt and i changed the fuel filter. The car runs perfectly when it's cold but once it warms up and gets hot, it loses power and dies off. It'll start back up and idle but i i drive it immediately, it'll try to die. If i let it sit for a few mins, it'll drive fine or a few miles. And when it's cold out, It'll drive fine for about an hour.


Some i'm thinking that something electrical is shorting out and over heating. I'm going to put on a new fuel pump and see if that helps any. But is there something else i should look at?

1973rx3

Check motor compresion. Most times i've encountered this is because engine needs a rebuild. I'm pretty sure this is not what you wanted to hear, but most times this is when you want to do a rebuild and not wait until something actually breaks (seal) internally and ends up costing you more (rotor and/or housing replacement).

jshiz

iTrader: (4)

If it needs a rebuild, it's no big deal. It's just a project car for me. I have a s4 6 port engine that i was figuring out what to do with. i guess i have to finish it sooner than later. Thanks.

t_g_farrell

iTrader: (1)

Thats exactly how mine started acting over the winter and it turned out to be
the ignition. Before I came to that conclusion I thought it was a fuel pump issue
as well. Changed that it seemed better but in a few weeks same issue, so it
was just coincidence that changing the pump had any affect

I never figured out what in the ignition box failed; ignitors, blown
circuit or what but I replaced it with my TFIDFIS setup and all was good. My SA
ignition box had a circuit board in it that had what looked like some toasted
components in it, so I'm thinking thats where the failure was. So check your
ignition first, when hot. The spark is probably missing or very weak on the
leading. Note that the SA will cut off the trialing in certain conditions to
maintain emissions, details in the FSM.

jshiz

iTrader: (4)

^That's worth looking at. Thank you. Cause all my friends are thinking my engine was fine. I'll do the 2ngdfis since i have all the parts handy and see how that works.

jshiz

iTrader: (4)

And for what it's worth, it wasn't the fuel pump. I tested it and it's working fine.

It'll fire up and idle (it's a little rough, i'm still figuring out how to adjust the carb) But it won't drive for any substantial amount of time.

After reading your direct ignition thread, i'll think i'll go with that.

t_g_farrell

iTrader: (1)

I hope I was able to help. Keep us posted on the outcome.

jshiz

iTrader: (4)

I borrow a Ohmmeter from a friend and tested (How described by my haynes manual) my coils after it warmed up and my trailing coil seemed dead and my leading was erratic. So maybe that's where the problem lies. I hope that's it cause I went through everything else.

Kentetsu

When you revbuilt the carb, did you remove and clean the fuel jets in the bottom of the float bowls? Sometimes, if they are clogged, the car will run fine until the chokes opens up. After that, it starts starving for fuel. Just a thought....











.

jshiz

iTrader: (4)

Everything was cleaned. But I'm going to let a friend look at it to double check to make sure i didn't miss something stupid.

DivinDriver

iTrader: (15)

Are you looking at the ignition coils (on the fender) or the pickup coils (in the dizzy?)

Remember to isolate them from the rest of the circuit by disconnecting them, or you can get false readings.

RustyRacer

How do you isolate them?

jshiz

iTrader: (4)

I did the coils on the fender and the ignition box. I didn't isolate them. I just follow the instructions in my manual. But I'll redo it and see what I get.

jshiz

iTrader: (4)

While letting my car idle some tonight i notice my fusebox was extremely hot after only running for a few mins... I'm going to poke with it once i get some light. I think i found my problem.

jshiz

iTrader: (4)

Ok, I switched all the fuses since he was running 30 amp fuses on everything so i replaced them with the right ones. My horn now works...

But I was driving my car for around two hours total with cutting it on and off repeatily trying to get it to cut off. It finally did it's thing like it was starving and cut out after a few hours of driving. I'm still lost what could be the source. I looked at my carb and I don't see any signs of flooding. I'm my next off day I'm going to go drive it til it cuts off again and go through the electrical system and see if i can find something.

RustyRacer

Here's what I just found!



What a hack job, the red wire isn't even connected and the black with blue stripe should be green and only has about 4 threads connecting. I think it was grounding on the plate and not letting spark happen. Is it recommended to keep trailing? What should I keep and throw out? I've got rats and emmissions removed with header. Aparantly I must have missed a rat or two.

DivinDriver

iTrader: (15)

IMO, On a mostly-stock car, you do want to keep trailing, yes. check carefully for other hackerage around your ignition system.

You need to use high-strand-count wire for those connections & solder them properly, since they flex constantly as vacuum advance changes & move the pickups.

RustyRacer

Thanks, can I just get those components? Should that trailing black thing be touching the rotating saw like the leading? I'm guessing that is a piezoelectric box to tell the ignitor to fire?

jshiz

iTrader: (4)

Hey rusty, post pics of your SA. it looks identical to mine.

t_g_farrell

iTrader: (1)

What your referring to is the air gap of the reluctor wheel (saw) and the pickup.
Its critical that the air gap be correct or you will get a weak signal. The reluctor
and the pickup should never touch as that would destriy the pickup fairly quickly.
The 80 dizzy reluctor design gives a weak signal anyway, so anything you can
do to improve will help.

The FSM gives the details on what the gap should be and how to measure it.

DivinDriver

iTrader: (15)

^+1

New pickup coil assemblies are apparently NLA (Mazdatrix used to list them but now no longer does). Good used assemblies are not real hard to find, the trick is the 1980 model is the only year that used that particular assembly. 79 and earlier used points, 81 and later redesigned the distributor to mount the ignitors directly to the dizzy rather than remoting them to the fender.

Most folks around here will recommend, unless you are going for a detailed restoration, that you convert your ignition over for an 81-or-later distributor. They are simpler of design and more reliable, and there are more available parts to be had since they were used for multiple years.

If the star-shaped center wheel (reluctor) is actually touching the pickup coil(s) (black plastic things) then you either have a completely worn-out set of pickups or a distributor with extremely worn bushings. There's supposed to be a few thousandths of gap between the reluctor and the pickup, as T.G. said.

If you can find a good used 80 distributor, replacing the entire dizzy would be the easiest drop-in fix. They do show up in the Classified section or on eBay from time to time, but you have to be specific that you're after a 1980 version.

RustyRacer

Thanks guys. My cap and rotor are not wearing unevenly. Could it be that the dingleberry who "fixed it" by bending them out? Found new pickup coils Borg-Warner at O'Reilly's for $140.

This may not even be the solution to the hot start issue I'm having but its the only obvious thing left. Guess I could go the TFDIS or any one of those options floating around here. Would I still need to get these pickup coils/distributor?



Cool jshiz, maybe our cars don't like being the colors they are. My friend has a very nice and loud MGB-GT and he gets surprised by how many people rubber neck to check out my RX7. Who'd have thought a $120 rattle can job could turn out this well.

jshiz

iTrader: (4)

Ah you got a sunroof. But grey doesn't hold up well to the sun. Mine needs paint badly too :/

RustyRacer

It's bright white with metallic light blue. I'm in Texas, trust me I know how the sun is, hence the umbrella. I haven't clear coated it since its just rattle canned paint. Did it in 85+ degrees and it's held up against gasoline, so I'm not too concerned. Well, not sure it'd hold up to the salty air you've got.

RustyRacer

Well, I got a used 1980 distributor for $32. Installed it today, starts right up when hot. However it won't idle under 1K (vacuum?) for me to adjust the idle timing. It wasn't having that problem before, so I figure the leak is coming from that. I had it timed perfect with the leading and pin and the circle and line on the distributor. This had it almost fully retarded, took it for a drive and the kids on the street were having a great time watching my car shoot flames out the back. I told them awesome and reved the nuts out of it, they liked it then I realized I almost burned a kid. Drove home and readjusted a little, but...

I drove it and now it bogs under 3000 RPMs, I ended up setting the timing at 1500 RPMs on the yellow mark. Having read some more I'm wondering if I can get the idle to 1500 and get the white point between the Leading 0º and Trailing 20º marks then between that would be the centrifugal 10º max at 1500 RPMs.

Also found out my original gouged out about 2 mm into the pickup.

I tried searching but everything came up 2nd or 3rd gen which only told me about TPS. I also looked at the FSM and it said to adjust on idle, but I can't right now.