Okay so heres the problem. The car is a 91 vert. Everything is original when it comes to the motor (for the most part anyway). My fuel pump was starting to go out, yeah I know that. I replaced the fuel pump, and I would have to give it 100% throttle for the car to go anywhere. I asked around and everyone keeps saying the same thing, fuel filter. So I replaced that as well. Well the car has been down for almost 2 weeks and I have no friggin idea what is wrong with the car.


It drove fine with the pump screwed up compared to it with a new pump and filter. Anyone have any idea why the car would run like **** after replacing the pump and filter? It seems that the car is fine just not getting fuel like it should. Thats my guess that its just not getting enough fuel. Anyone ever have this problem or know what the deal might be?

Could it have anything to do with the ECU? I have not messed with that PERIOD. It just seems like the car is struggeling to run and needs full throttle just to go any where and will die or just not want to go any where.

Any help would be friggin GREATLY GREATLY appreciated. I just want my baby back on the road again I miss her hahaha

 

Really no one has any idea? lol

The mazda shops haven't been any help, going online doesn't seem to be helping either and yes I did search on here. I just haven't found any useful information. So what just pull out the rotary and slap the 350 in there??

 

hows your compression?
on my old motor i had kinda the same problem, it was slow as *****. Turned out it had a dead rear rotor

 

I know the pain of having the car off the road, but give the board some time. The smart people won't get here for a few more hours.
Is this a problem throughout the rev range? after 3800rpm only? Is it just because your car is missing a turbo?
Here's some stuff to do until then:
-Throttle Position Sensor calibration
-Make sure feed and return fuel lines are correct (may prevent car from running completely, so maybe not)
-Plug wires hooked up correctly?
-Good spark plugs & wires - look for electircal arcing, near the boots especially
Hope this helps.

 

lol alright I shall wait till the smart ones arrive haha.

Nah its pretty much throughout the entire rev. I guess I should have provided a little more info on the car. Its a 91 Vert NA. Now I did replace the fuel pump like I had said but I did not replace the sock that goes with the pump. It didn't come with one when I bought the pump. It was cleaned though but I guess I should replace that as well? I mean I highly doubt that that could make the car run like it is but I dunno.

 

Eh I don't think its compression it seems like the car wants to build power but just not getting enough fuel or something. Its very weird. I can get a compression test done I guess. Couldn't hurt

 

I'm dealing with a plugged sock, the screen at the bottom of the fuel pump. I'm sure that's why I lost power going round corners, clean out your screen, Hailers just told me how to remove it on my original post.
Mike

 

Probably not fuel sock unless it is extremely clogged. I believe a bad fuel sock will show up first as hesitations when cornering and then escalate to all out weak flow. You can try the cheap compression test of taking a plug out, pulling the EGI fuse and listening for even chugs as you crank it. Apex seals can go at any time for apparently no reason. Hopefully not your case.
I highly suggest the Throttle Position Sensor if you have not set it recently.
Also, can you accelerate decently at ~1/4 throttle and then it bogs if you push it harder? Or is it just weak all around? Does it rev well in neutral? Let's get that 7 back out there.

Edit: Hailers=Smart one.....me=not so much

 

Yeah I hope its not the apex seal. I will have to check the throttle position sensor then I haven't messed with that. I COULD accelerate decently around quarter throttle when the pump was going out. Now when I try to go anywhere I have to give 100% to go. Even then its not going anywhere far. It revs eh alright in neutral just not like its suppose to. Just seems like its losing some where. Whether it be fuel or what. Yes lets please get it back out there! haha Thanks

 

Well for what it's worth my sock was plugged to the extent that when I pulled the fuel pump assembly out of the tank that sock (screen) was so plugged that the gasoline sat in it like a fishtank. I ordered a new one as I do not think I can clean it out, because it has an the inner part and very fine mesh indeed.
Mike

 

dump out the CEL codes. It's real easy to do on the '91. Sounds like the car is running in limp mode.

 

Probably not going to be a surprise, but I honestly don't have any idea how to go about doing that or where to start for that matter. But yeah she is "limp" haha.

 

http://rotorwiki.com/index.php/89-91_Error_Codes

 

Ahhhh pimpin, Thanks HAILERS! Hopefully I can get her goin again. I will post an update to let ya know how it goes.

 

if there's no codes, i suspect you may have a dead catalytic converter or 2. my T2 got to the point where i could barely get up to highway speed at WOT, lucky it didn't spit out the apex seals from retained heat in the engine.. you could also have a dead spot in the TPS which would cause severe hesitations and may not throw out a code.

to check the cats you have to do it manually by unbolting the mid section of the exhaust where the cats live and shine a light through the exhaust front to back, it should look like an even honeycomb and you should be able to see light through from the other side. if the cats are dead or dying it will be cracked and pieces falling out or wedged sideways blocking exhaust airflow, it would also likely rattle if you shake it from pieces rolling around inside. in cases of oil burning engines or excessive additives to fuel, the cats can just be caked with carbon and completely clogged up but not broken.

to check the TPS, find the TPS on the front of the throttle body, turn on the ignition key, hook up a voltmeter black wire to ground at the battery and red probe to the green wire in the TPS, do a slow throttle sweep while watching the voltage, it should go from 1 volt at closed throttle smoothly up to 4.5 volts-ish at 1/3 throttle. any spots where voltage drops, goes open or spikes means your TPS is dying or dead.