Enigine Stalls if you abrubtly hit gas????

[blueskyguy007]

Hey Guys I'm new to the forum but not to the car. I've looked throught the board already and couldn't find someone that had the same problem I'm having

The Problem: the car runs fine and idles ok but when you go to call upon the engine for even a lil bit of power it acts like there's no fuel going in and trys to stall but usually never does. (engine speed drops to like 200rpm just about)

Other Useful Info: Well the car ran fine the night before it started doing this (no i wasn't street racin ) Next day i moved my car and washed it (not the engine) then was headin to the store and it seemed like the car didn't want to go at all. Kind of like it was in 5th when i started. Weird thing about it is that i can rev the car by slightly hiting the pedal and make it go to 5000rpm (didn't try to make it go higher but sure it could) i still can't make it give me much power though. I replaced the fuel filter thinkin it was clogged...no luck. My air intake in kinda rigged with tape around it to seal what i guess is a busted tube ( above the mass air flow and before the tb) so i made sure that was sealed because it had given me problems with my idle at one time. I took off the tube thats after the mass air and before the tb that leads next to the disty ( checked that too I might add) and it had almost a shot of oil in it??? so I then looked at the tb and it seemed like there was oil coated on it. I don't know wtf could be causein that or if it would cause the engine to do that. Another thing I might add is that right when i hit gas and it starts to stall i hear like a suction noise and seems like it gets choked off.If any of you guys have any ideas of what this might be I'd greatly apprecaite it. I'm probably gonna check into the fuel pressure regulator next. Thanks

-Aaron
92 Mazda MX-3 GS V6 stock as ****

[TsiMiata]

Check that the air meter plug is plugged in and tight.

[IanL]

I don't know if this would account for your problem, but there is a high probability your PCV valve is stuck open. Remove it and check you can blow through it from the end that goes into the valve cover, but not the other way. If it's stuck, replace it.

[blueskyguy007]

Ok I checked both the PVC and the connector to the vaf and both seem ok. Although i was wondering since there was a bit of oil in the intake if that may have gotten on the VAF and causes it to misread??? If anyone has anymore suggestions that'd be great cause I'm ponderin and ponderin over here tryin to get my baby back on the road.

Thanks
-Aaron

92 Mazda MX-3 GS Tropical Green

[killerpickle]

Maybe unplug the VAF start the car, and see if any of the conditions have changed. This could rule out the Vaf being faulty or not. If there is no change then the Vaf has gone for the ****s. I remember when I redid my intake I forgot to plug the vaf in and the car barely moved...

[blueskyguy007]

I plan on checkin out the mass air flow meter in the morning...One other thing I thought may be causin the problem is the EGR valve or vacuum to it. I read in the repair manual that if a strong enough vacuum is deliveredd to it that it can cause the engine to run rough or stall. That be my next guess cause it seems like I hear a suction noise when I hit the pedal. One thing I forgot to add is that I've adjusted the idle speed about two weeks ago to 800 or so instead of the 650 like it had been doin. I really don't think that this would cause this problem though but you guys probably know alot more about this than I would. Oh yeah and some people have told me that it may be water in the tank...I doubt this too since the car runs perfect while idleing and doesn't sputter at all. Why I'm guessing that there was a lil oil in the intake is because the EGR lets the exhast gases into the intake and since my car has 187000 miles on it and probably has a lil oil in the exhast is how that got there. Does anyone know if the lil hose thats right before the tb is where the egr lets the gases in??? If so that would more prove my theory. Someone drop me some feedback and lemme know what yall think.

-Aaron
92 Mazda MX-3 GS

[killerpickle]

You can hear a suction noise? If you dont have a cold air intake, there could be a nice vacuum leak in the intake assembly.

[blueskyguy007]

Oh well you see my intake is really ghetto (aka pretty much tape holding it together lol like right before that pipe that goes to nothing and after the air meter the pipe had been electrical taped up by the previous owner...it became messed up while drag racin it a few weeks ago (since the whole car shoke while tryin to gain traction) and I had to retape it so it wouldn't let air into it and make the engine stall everytime I cam to a red light. But that is "fixed" for the time being so I know that it's not that. I thought it may have also been the fuel pressure regulator but I'm kinda skeptic of that since it's main function is to just send unused gas back to the tank that the injectors didn't use.

[IanL]

The little hose supplies air to the EGR Vent Valve to relieve the vacuum in the valve when the valve has to shut. It is in the valve control loop, and does not get to connect to the exhaust gases, which are fed into the intake after the throttle. So that is not your path for the oil.

The oil almost certainly comes from the pipe which admits fresh air into the valve covers when the PCV valve opens and sucks the blow-by gases out. If oil has got up that pipe, I suspect the PCV system is not working, and the blow-by gases are taking that way out.

[Gro Harlem]

when you give it throttle and it dips in idle...can you hear popping sounds like its backfiring?

If so..replace the O2 sensors. thats what i had to do and it eliminated that problem.

[blueskyguy007]

Well I checked the mass air flow meter and all it did when I diconnected was trouble light (lol I'm thinkin of my rides at Six Flags ie: trouble light) CHECK ENGINE LIGHT and the car ran like ****. Yeah it is makein a popin sound and sometimes does back fire. But for the most part it just dips really really low and you can't get any power from the engine. The exhast has also been smellin a lil bad, but this maybe due to the fact that I've added B12 Chemtool to the gas to clean it out when I tought it may have been a fuel line problem. Also if it were an o2 sensor, wouldn't that give me a check engine light????Thanks guys for all of your help and feedback.

-Aaron
92 Mazda MX-3 GS

[Gro Harlem]

no, i didn't get any check engine lights...at least not on my car. My 02 sensor caused a crapload of weird problems....mostly that I couldn't give it more than 20% throttle without it backfiring and running like crap like you are describing (i drove it like this for over 2 months before assessing that the o2 sensors were to blame!)

I replaced both of my o2's with unviersal ones...they cost me 18 bux each from autozone. The oem mx3 ones are 4-wires while the universal ones i got are 1-wire...you only need the signal wire (blue wire on the factory o2 senosrs), the otehr 3 wires on the mx3 one are for the heated element w/in the stock o2's.

If you wanna get replacement OEM ones, they cost about 90 bux each...that is ridiculous IMO which is why i went the cheap@$$ route.

<small>[ October 06, 2004, 05:38 PM: Message edited by: Gro Harlem ]</small>

[perhapsadingo8yerbaby]

Originally posted by blueskyguy007:
...Also if it were an o2 sensor, wouldn't that give me a check engine light????

Nope. I had to replace one on 2 different Mazdas, (MX-3 & MX-6) and a Toyota Camry and never got the CEL on any of them.

[blueskyguy007]

OK i've taken out my front o2 sensor and it was all croded and such but I also wanted to make sure that this was what was given me the problem so before I took it out I disconnnected the conncector and ran the engine and it ran just like it had been doing...Do you guys think that this would be an adiquite enough test to make sure that this is the problem??? I thought it might have also been the throtle position sensor??? OH yeah, the Check Engine Light did NOT come on when I dissconnted it so this better reassures me

<small>[ October 07, 2004, 02:04 PM: Message edited by: blueskyguy007 ]</small>

[Gro Harlem]

Originally posted by blueskyguy007:
OK i've taken out my front o2 sensor and it was all croded and such but I also wanted to make sure that this was what was given me the problem so before I took it out I disconnnected the conncector and ran the engine and it ran just like it had been doing...Do you guys think that this would be an adiquite enough test to make sure that this is the problem??? I thought it might have also been the throtle position sensor??? OH yeah, the Check Engine Light did NOT come on when I dissconnted it so this better reassures me

Dood stop being lazy and just replace them. Obviously the test proved that your O2's are to blame.

Use the universal ones like i described above tho..they work flawlessly and only take 1 minute extra to warm up on cold days. i've been using them for 6+ months now without issue. And they cost 1/4 as much as OEM replacements.

At the parts store, ask for an OEM replacement for a 90-94 Protege (doesn't matter which engine) they use the same one. I think the Bosch part number is 11x52...can't quite remember the middle number.

And when hookin it up, the BLUE WIRE on the 4-wire haress is the one you want to splice the single wire into. I just took my old O2's out....cut the harness off RIGHt where they meet the O2 and used the harness directly on the new O2's thing using a crimp connector and it hasn't failed yet.