Car Hesitates and does not like to idle warm

[nerd racing]

So I got my 4wd protege running and driving (1990 5 speed with a BP swapped in)... except for one small detail...

It runs great when I first start it cold, if I give it 1/4 throttle it has plenty of power. If I put the pedal down it falls on its face, it will stall if I take out of gear and coast too. As soon as its warm it barely idles, maybe 300 rpm and dips to almost stalling.

I'm changing the fuel filter tomorrow, spark plugs, and cap and rotor.

The 4 wire O2 is new and wired correctly, I did a quick check for vac. leaks but didn't find any. Could my TPS be out of adjustment?

Is the stock BP VAF adjustable? It looks like someone had the cover off the one I have because it seems to have been re-sealed.

I replaced the ECU with another one I had and it ran the same.

Anything else that could be going on?

Also it seemed to be running rich at first.

[Ace]

Sounds like a tps issue to me. Try another one? And yeah you can adjust the vaf but that doesn't sound like your problem.

[Mazda_Powered]

Any check engine lights on? Have you jumped TEN & GND to see if there's any codes stored?

If it runs better cold, it could also be the coolant temp sensor, which has the same symptoms.

[Wilyb]

What Mazda powered said...don't discount a plugged cat either...

[Mazda_Powered]

Ya true, friggen cat converters...I've seen so many clogged ones in my time, and I'm only 26 lol.

That's an easy inspection tho, just disconnect the downpipe and go for a quick rip lol

[nerd racing]

whole exhaust is new, 2.25" from manifold to cat, and cat and back 2.5"

Good call on the temp sensor. I'll see if there are any codes stored. I may have to do a junkyard run for a temp sensor and a 3 wire TPS... Could it be out of adjustment?

[Wilyb]

temp sensor is 12 bucks...

[nerd racing]

awesome I'll just get a new one then. I figured they were around 80ish seems to be the magic number for other thread in sensors.

[yunvmyegt]

isnt that an auto car, why the need for a 3 wire tps? if you really need one i probably got 2 or 3 in the other room..... come and get one... no 4 wires tho, if thats what you meant to write..lol.... and i think i have a few of both styles of temp sensors too

[nerd racing]

I don't buy automatic cars man! I have a new 3 wire on the way, along with a new coolant temp sensor, and I broke the tab off the gage cluster temperature switch so one of those too. They will be in at 6:30 then I'm going to change them and give it another go.

I changed the plugs, cap, rotor, and fuel filter. It fired up and idled beautifully... until... the check engine light kicked off after the startup cycle... then it was back to that bad idle crap, but this time it would not stall. so... I'm thinking its the coolant sensor. But I bought a new tps too.

[yunvmyegt]

ya wow im shot i forgot you put a stick in there, or atomic and blazin did or what ever...lol...

[nerd racing]

it was a 5 speed when Jon had it I believe. I don't think it was ever auto.

[nerd racing]

also the plugs were black as black can be! I put some NGK's in there.

[yunvmyegt]

really, i dunno wtf i got auto from then....lol... you might get lucky with the temp sensor, if its reading open or way too cold, itll just dump gas.....

[nerd racing]

I'm going to put it in and then if that doesn't fix it I'll change the TPS.

T-30 mins till new parts!