P'cola FD

This is nothing but a bribe, but there aren't any rotary mechanics around here that know anything, other than me, and I hardly know sh*t.

First off, my engine has 20,000 miles on a mazda reman. Rebuilt turbos 3k ago and hose job 3k ago. The engine pulls strong ans the turbos boost properly.

Ok. Here's my problem. It started about a month ago; on hard launches the engine would stop for a fraction of a second and then come right back to life. It almost seemed like fuel cut, but I have a Pettit unlimited ecu.

Then, every once in a while, between 2,000 and 3,000 rpm the car would hesitate, and jerk a little. I figured it was the plugs so I bought a new set. After 15 minutes of driving the symptoms returned. I wanted to see what would happen if I pushed it, so I did. Engine ran smoothly and had no problems(or pops). But as soon as I got back down into cruising speeds, the engine was hesitating like a bitch, sounded like ***, almost like it was running on one rotor, and had little power below 3500 rpm.

It was running like this for a while, and then all of a sudden, it ran normally. Everything was cool. Then, before you could say "whew" it starts F#cking up again. Idle drops to 300-500, 10 inches of vacuum, shaking like hell. And then, it smooths out 850 rpm idle 20 inches of vacuum, no shaking. Etc, etc, etc.

I tested my coils, put new wires in, cleaned the plugs that keep fouling, and tried a new MAP sensor all to no avail. Now my car likes to flood, so I checked my fuel pressure and found it to be too high. Changed my pressure regulator(thanks spyfish007) to fix it and that didn't change anything. Called Racing Beat(no one else was available) and they said that 45psi of fuel wasn't to high with the key on, even though the manual says it should be 36-38.

My ECU isn't throwing any codes, and I have almost everything off of the top of my engine. I know I have an oil leak somewhere in the area of my MOP, but it's not big. Could that have anything to do with it? While my engine is tore down do you have any suggestions? Should I pull the fuel rails and test the injectors? I suspected my ignitor, but can't test it. Should I try someone else's ignitor?

I know this is pretty long, but I've done countless searched, made countless phone calls, and am pretty desperate. Any help is greatly appreiciated, and for the person who can figure this out I will mail you $100 cash, and give you major props.

RonKMiller

You're going to hate me in the morning: Fuel filter!

"When you hear hoofbeats, don't go looking for Zebras"

PS, I would prefer a money order. Good luck.

ejmack1

have insurance

but seriously i would have though a map sensor.. it looks like you covered most of the obvious, dont know what to tell yah

P'cola FD

If it was a fuel filter, wouldn't it show some kind of sign on the fuel pressure gauge? I already have one on the way, but if that's it I'll still hook you up. But seriously, The fuel pressure gauge should have shown a slow build up if it was a filter shouldn't it?

rx7speed811

you might want to check your pcv valve and clear it out, if a new fuel filter doesnt help. its only supposed to flow towards the upper manifold, not the other direction. it seems like you already changed out everything else besides that.

P'cola FD

Sorry I didn't mention it before, but the pcv is in working order as well. I've checked a bunch of sh*t.

RonKMiller

You would think so...... but - frankly I'm just like you and don't know **** from shineola half the time. But I do frequently use the WAG principle when working on problem solving (wild *** guess) and generally speaking if you throw enough new parts and money at something you'll eventually fix it! Since you've already got one ordered I'll settle for $50.00 and an "attaboy". Hope it works!

Oh, btw, I've got a friend named "Louie" in South Miami and he collects on ALL my debts for me. First he breaks your left thumb... then he breaks your right thumb.....

P'cola FD

I'll let you know if it works Ron, but in the meantime, anyone else have any ideas. Since I've got the intake and everything off already I'd like to check the injectors or anything else in the vicinity if that could be the problem, but if there is no trouble in there then I'd like to put it back together to try other ideas. BTW, tell Louie I said hi. He sound like a nice yong gentleman. I'll probably be seing a lot of him soon. J/K

P'cola FD

Oh yeah, one more thing that it sometimes does that could be unrelated, but wtf. Every so often it acts like stalling and there will be a clicking noise like a relay, and the cooling fans and airpump act funny. The cooling fans will come on when the engine is literally cold. But this only happened a few times and for a very brief period of time. ???

Bucrx7

This may sound weird but check your alternator. Your car drops idle to 500-600, vacuum is 10 after you step on the brakes and the fan turns on?

Touring FD3S

Try the Throttle Position Sensor (TPS). Especially the plug and wires going into the TPS. If the wires get loose, it will make your car hesitate, run like ****, etc...but if they get knocked back a little, your car will run fine. Pull the plug out, inspect wires, check connections, etc....plug it back in and check. Sometimes just jiggling the wires helps too. You might try it once and it won't work, but I suggest trying it a few times.

P'cola FD

Idle drops when it wants to. Fans coming on isn't often, and brakes don't matter.

Who else is getting sick of "the server is too busy"? I'm not bitching, but dang.

P'cola FD

I've already tested the TPS and wiggled the wires every which way. Anyone else?

P'cola FD

I thought that once it first started cutting out on launches and have been going to chevron and premixing since. BTW Dont_Be_A-Rikki, your site rocks, Heywood Jablowme, that's some funny stuff.

P'cola FD

I'm almost positive the motor is good. I'm not sure where to start looking with the electrics though.
New develpoments: intake air thermosensor and fuel thermosensor are good.

hawaii rx-7

try checking the grounding.

P'cola FD

Oh yeah, I have two extra grounds going from the negative battery terminal to the threaded strut tower hole and the alternator bracket.

Should I pull my injectors and send them off to RC or does this sound like something else?

KZ1

fans coming on too early eh? ahppened to me, it was some bare wire from the relays acting up, check allt hsoe cooling realys for operation, etc.

BTW, coudl also be the waterthermosnesor, pull it and test it. it adds extra fuel for cold temps, if it is off coudl make you run really rich, mine did, when I replaced it car ran great but idels and fans cam eon at right temps

Crazy_Jake

did it do this before the ecu swap?

P'cola FD

I've been wanting to test the water thermosensor, but before I bought it someone must have broken the connector or the sensor and tried to fix it, because there is a bunch of epoxy on there. I think Maztech might have done it during the engine replacement.

P'cola FD

Crazy_Jake, yeah it did. I've tried a stock ecu and the Pettit, no difference.

Crazy_Jake

How did you check the coils?

P'cola FD

I checked the coils with an ohm meter via the service manual directions.