Under Load She Shuts Off!!! Help
 

Bought a 1975 mazda rx2, has 81 thousand original miles...has many new stock parts that were changed out and replaced...Here is my issue...

For the past three weekends manny vidal and myself have been trying to figure out why the car flutters, then shuts off under load...When i say under load, i mean driving...She rolls out of reverse fine, then we put her in drive, and she starts to build speed she is good for a few seconds then going from First second gear, she starts to flutter, bog out then shut off...Car has a auto tranny...

We just recently swaped out the stock carb and intake manifold, and dropped a 12a holley racing beat intake manifold with a holley carb...We thought that there may have been soemthing wrong with the stock set up...And even after dropping in this new holley setup she still does the same damn thing...

She idles fine, she revs up fine, but soon as we start to drive her and put her under load...going from first to second she dyes out, flutters, and just dies out...

Anybody got some ideas, imput, info, they help me out with...The points on the dizzy are dead on, brand new, and on point...Coils are working fine, wires are spark plug wires are hooked up correctly...

I was told that sometimes with these old cars...when there under load and start driving the fuel system gets clogged or doesn't allow for enough fuel to pass by causing the motor to die out...I was told to dissconect the feed line going into the fuel pump...Hook up air pressure to blow back in to the tank to clear the line...:scratch:

Definitely sounds like clogged lines.

But thats crazy...I understand my own term "under load" she dies out, but how is it at dead stop, idle, we can rev her clean with no problems? Then she drops back down to normal idle and we can rev her back up with no issues...but soon as we want to set her lose on the street she wants to die out on us?

Sure sounds like a fuel delivery issue. Do a pressure and volume test at the carb.
If either is not good move back to the pump. If thats not good its either a pump
or a feed issue from the tank. I'd connect an external pump to the tank then
and see if it works ok or not. If not then its a feed issue from the tank. Oh
and make sure its got a fresh filter.

The reason it idles ok and rolls out fine is your running off the float bowls and when
it empties, the fuel is not keeping up so it dies as the bowls run low. Then you park
it and start it again and the bowls slowly fills while its idling and rinse and repeat.

Start with the fuel filter. If it looks like the inside of a used cigarette butt, get a new one. If you don't have filter before the fuel pump, consider putting one there as well.

ok...going to try all this friday...there was a major over hall on the car before i bought the car with new parts...there is new filter just before the carb..not sure if there is one before the pump...

I need your help again you all..

I changed out the stock pump, with a holley blue, and also a holley blue regulator...

I set the pump to 5-6lbs...I got the car running and got the car to idle...But the car STILL does the same thing...When i get the driving it, and under load she shuts off...

I also tried keep the car rev'd at about 5 grand, and she does the same thing...So i fig'd air is getting in some where...

So i started the car again, and sprayed carb cleaner around the carb and the intake ports...She starts to die out or wants to cut off/shut off...I tightened all the bolts around the carb, and around intake manifold...and nothing has changed it still does the same thing...Holding the throttle at 5 grand or so she wants or will shut off...

Driving the car in reverse or in drive she shuts off...

Any more thoughts on this issue? I need help asap thanks

Special thanks to wacky for taking the time to help me somewhat fix my starter relay problem for the momment...

yw. get a wet towel and wrap it around the coils and see if that helps. them coils can go bad when hot.

was that a legit response wacky? Cause i know your always fucking around with me...

either way i will try...

I've never owned a rotary with an auto so I'm not sure in this. Does the tranny have a vacuum line hooked up the the intake manifold? If so check that out for cracks. I think before computer days, the tranny would change gears based on rpm and vacuum. Good luck.

you got PM Teddy:)

Somebody told me the same thing with the vacume post you are talking about...I do see a few vacumes coming off the tranny one is getting dumped on the passanger side of the car fender like a vent tube...I have to look for others...The only one i got hooked up to the manifold is the brake booster...

Got your pm junior i will give you a call

Teddy, you may have a torque converter lock up clutch locking up. This can cause the engine to shut down. If your fuel and ignition checks out then I would look into this. Besides get rid of that turd auto and put a manual in it. I have an older first gen trans for sale if you want.

Tranny
 

yeah everything is checking out with the spark and ignition those are all okay...I even put the stock original fuel pump back in cause i want to keep it as orginal as possible while the new one order from becky or some shit or another comes in...Its an exact fuel pump replacement for the stock...

The tranny does bang into reverse drive, neutral very fucking violently...it fucking scares the shit out of me...The only way im able to drive the car is just letting it roll at idle in drive lol...If i start to gas it, she starts to choke and die...

Bout your tranny, you talking about the 79 SA tranny? Or the mazda rx2 tranny that has the ol school 4 gears in it with the top mount starter location? If its the 4 banger that would be gangster bro...pm me a price..i have the set up here to convert it over to manny...even though idon't want to...i guess i will

Hey Teddy,
I have the original 4 speed tranny from the 74 Rx2, even has the old skool wooden shift nob lol. You say your car is a 75 I thought the end production was 74. Do you have any pics of the car?

Teddy will enjoy that wooden shift knob LOL

lol

I don't member saying it was a 75 the 4 door i have is a 73 automatic...

Aside from that the auto tranny checks out just fine there are no vacum leaks cause there are no vacum lines anywhere except a breather that gets dumped on the passanger side fender...She shifts harshly but thats just age and i can live with that for now...I will be doing a compress check, im guessing this might be last resort since everything is checking just fine...Coils are good, timming is good, intake and carb are fine, fuel is fine, im just dredding the fact that i might have to yank this fucking motor if one or both rotors lost compress...

So in other words...Im trying to hold off in doing a mann swap to limit my spending cost, i really want to keep it OG auto...and going with the original 4 banger with the OG wood shifter sounds nice...but i want to limit the amount im spending...

I will post pics here soon...

LOL...:lol:

Are you sure fuel delivery is ok? It might have enough in the bowls to idle but sucks it dry when you stomp the throttle.

I had a problem with the rx3 and then a few years later with my Minicab. I could drive the rx3 around just fine but, would crap out after 10 seconds at WOT. Turned out to be debris in the tank.

The Minicab was a nightmare. I couldn't touch the gas or it'd die. But I could idle around town in 4th gear if I REALLY needed to get it somewhere. I replaced pump - worked for 1 week and thought I fixed it... until it did it again. I rebuilt the carb - worked for 10 mins. Was so confused by the fact that these things worked for even a little bit. Turned out to be deris in that tank, too. WTF?

You might want to take the fuel supply line off the pump and give the tank a blowjob. It might clear the area of any debris long enough for you to get a hot lap in.

If you think vacuum is still possible. Get some needle nose vise grips out and pinch one line at a time, test drive, and repeat.

FUEL!

I swaped in a a brand new holley blue last week...I also swaped in a holley blue regulator to see if that would solve problem...It did the same damn thing...i was running circles getting pissed off with it...lol...i was going to let the car idle in drive, jump out during while it was rolling and let the car crash into a while...lol...

But yeah i tried the whole fuel pump thing...Ima going to buy another fuel pump since i took the holley blue back and replace the stock one i put back in there with a new stock replacement one they have on line for $50 and see what happens...

As far as debri, your right on that...cause when i took out the OG fuel filter that was back there to replace it and put a new one, that shit was full crap, rust, and junk in there...I put a new in, but i never gave the tank a blow job...So i know the tank is full of shit...what the best way of going about this to clean the tank out? Drop it, or run a compression tank with a tube hooked up to it?

A forum member hit me up through pm telling me he had the same problem...turned out his rear rotor was no good and lost compression...yanked the motor rebuild the stock block, and she runs great...I don't know im losing my patience with it...And i really want to drive the damn car already...

thank you guys for all your help...

Its a fuel problem.

Okay but what about when i spray around the carb with carb cleaner and she wants to shut off? whats that about?

Hey doc got any tips on cleaning out the tank? Should i just drop the tank? or pressure blow the tank some how? if so how do i go about doing this?

Drop it. It's not as hard as it sounds. Once it's out, remove the sending unit and you should be able to see in there with a flashlight. I used a garden hose to blast the stuff loose. Put a few liters in there and shake it like a mofo, too. If it's rusted to shit inside... consult the forum. I was lucky enough to just have leaves and dirt in there.

If you've replaced a dirty filter and the new one already has visible debris in it. It's definitely got debris caked around the fuel exit of the tank.

If you're a REAL scientist and don't want to drop the tank.... take a gas can, jerry rig the pump so it sucks fuel from it (instead of tank) and go for a boot! Don't light yourself on fire though.. because I will feel responsible. :)

LMAO...If im going to do it right im going to drop the tank...I just hate the extra work you know lol...

Anyways i will be dropping the tank this weekend and going from there, changing the fuel pump again, all filters and see what happens...thanks doc, tree, and everybody else for your help...