HELP fuel cut/boost cut/air cut/car fubar'd
 

I have spent hours searching this forum, mazda24/7, torontomazda, yahoo answers, etc and tried numerous things to try and fix this problem to no avail. I need help.

The problem:

Every morning (I mean EVERY morning) when the car is cold from sitting over night, I start the car and it turns over fine, starts with no problems, idle's great, like everything is as it should. Then when I go to leave and go anymore then about 20% throttle (push the peddal 1/5 the way down) I get a severe lurching/hesitation from the car similar to a new driver trying to learn how to drive a standard. The problem disapears after 10-15 minutes of driving (well after the guage has reached the middle of the temp scale). At which point the car drives completely normal and boost is built without issue. WOT acts completely normal and there is never any smoke while driving the car.

This happens without fail every time I go near the throttle, in every gear, at any RPM. If I rev the car up very slowly to 3000rpm in say 2nd gear, then attempt to build boost, the hesitation/lurching described above happenes. If I do the same, but rev slowly to 4000 or even 5000 RPM then attempt to build boost, the same happens.

I have put in new oem spark plugs (now with under 100km), checked the coil packs (all seemed good), done an oil change (which the usual oil), re-oiled the intake, done a visual inspection of all hoses for cracks or holes, and checked and re-tightened all clamps. I also checked the MAF and it was NOT dirty however I will be cleaning it with CRC MAF sensor cleaner tonight anyways to rule that out for sure.

The only other things I can think of is the main O2 sensor, fuel pump (in some way), computer programing (switching from STFT to LTFT?) or the fuel injectors. But if it were any of these then the problem would be present throughout the entire drive would it not?

I am at my wits end here...I am completely out of idea's and I know how much you guys hate when people don't search, so please trust me I have spent hours searching and want some more input before I start spending hundreds of dollars on fuel pumps or O2 sensors for no reason.

Car/modification info:
2007 Speed 3
91xxx km's
Cobb SRI
Corksport Cat-back
STOCK fuel pump
STOCK spark plugs/wires (recently replaced)
Recent oil change with full sythethic and new filter
Shell premium gasoline all the time and the tank is never less then 1/4 full
I always drive the car easy until it is warmed up (more so now then ever)
I only built boost or go WOT above 3000 RPM and never in 6th gear.

I do not have an AP so I have no way of monitoring what is going on and I don't really have the money to purchase one (university student)

Any help is appreciated, thanks for reading and I will update this if I think of anything or if problem is cured.

[Not so]SpeedyGuy[anymore] :(

UPDATE

Problem had been solved, a completely new fuel pump + internals were installed and the car runs flawlessly now. Unfortunitely, I am not able to say for sure if it was the spill valve, internals, or the pump entirely that failed (cause everything was changed at the same time). Either way, replacing everything solved the problem.

Thanks to everyone who helped diagnose the problem, aquire parts, and install them. Alot more money would have been spent without you guys.

What's yer spark plug gap?

Gapped to 0.031, I understand it should be a little less (0.025-0.030 if I remember correctly) but I was running out of light to work so 0.031 is what they're at.

have you stretched the coil springs?

No I didn't, they looked fine to me. However after finding the thread on how to do it I will probably get that done tonight as I have not found any ill effects to doing it so.

Does the spark plugs/coils sound like a viable problem?? Or could it be someone else?

I feel like you probably would have mentioned this, seeing as you were pretty thorough in your op, but you dont have a cel right?

Maybe a temp sensor malfunctioning???

Thanks for reminding me, there is no check engine light, and not even any codes.





Sounds viable, how would that effect it though?

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I doubt it's your spark plug gapping although you should close that gap to a .028 or .026. You need to post logs here if you have a DH or AP. Whens the last time you cleaned your MAF or did a boost leak test?

Whats the weather like there??? Severly cold I assume since its canada.
Does the issue come up if after you compleatly warm the car up ( drive for like 15-20 min) turn it off and then restart and try to drive.

I'll have to recap eventually but that shouldn't be causing it if it's off by so little. I don't have any way to log and don't have the money to purchase one at the moment (not easily anyways)

Edit: I cleaned the MAF sensor tonight and stretched the spring coils so I'll see what that does in the morning. Will update then.
First, not that cold here yet. And the problem has been arising in 'colder' and warm whether, it completely depends on whether or not the car has been sitting and has cooled off. The problem in non-existent when the car has completely warmed up after 15-20 minutes of very easy driving.

MAF cleaned, springs stretched, no change. Anybody???

I used to have the EXACT same problem, subbed

Do you have a ported intake manifold?

Use to? What did you do?
Negative. This car has no tuning done to it either.

Stock im. I simply started my car like 5-10 minutes andet it warm up before I drove it. That was on a ethanol mix. Then my fuel pump shit the bed ( install fail, nothing to do with ethanol). I'm now on pump and cpe fuel pump and haven't had it happen, and I do not let my car warm up anymore. It kinda just disappeared and I don't know why.

Hmmm.....hopefully its not the fuel pump...can someone chime in on whether or not this could be it? Low fuel pressure could cause this I guess, but I don't know how it would get better once the car is warm.

Complete guess, but I would think that when its cold there is a higher load which in turn increases demand on fp? My internals were installed wrong though, and I don't even know if that is what was causing the issue.

You're either running too rich or too lean causing it to bog.

You can run too rich/lean because the MAF is not reading correctly or you have some sort of a vacuum leak and it's worse when the car is cold since the ECU commands it rich anyways. Check for any air leaks.

Also pull your spark plugs and look at them. Do they all look the same and reasonable?

Finally, are there any noises, smells, etc. that you associate with this condition?

I just cleaned the MAF last night with MAF cleaner and the spark plugs were just replaced with bran new oem equivalent plugs gapped to 0.032.

There are no noises I can hear, or smells, or smoke from the car (had a following car observe).

I did a visual inspection of the hoses but have not done a vacuum check or any air leak checks. I will get that done ASAP. Thank you very much for the help I will let you know how that turns out.

No boost leaks. Upon closer eximation of cylinder 3, the spark plug is pretty chewed up. Ignition cylinder springs have been stretched, but no luck. New ignition coil going in cylinder 3 next week so hopefully that fixes everything...

Wait... Describe "chewed up" in reference to the spark plug.

I don't know how much you can see in this picture, but look at the middle spark plug in the pic, you'll see what I'm talking about (if you can see it)

Edit: open in new window/tab, then zoom in and you'll see what I'm talking about

I would like to know that too, a "a chewed" up sparkplug could indicate something more sinister.

Looks like that middle plug is pretty well fouled.

Tapa

The middle one is "chewed up". Haha that's all I could think to describe it, but you guys get the point. Unfortunately that was not the cause of my issues. I think what caused that is what is causing my problem. Maybe. Unless someone else has another idea?

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Fouling can be caused by a lot of different things.

That looks like carbon fouling from the picture, which is "better" than oil fouling.

Could just be caused by a fuel mixture that's too rich.

I would replace that plug regardless.

Tapa

those are pics of the old plugs right? not the new ones that you just installed

my money is on bad maf sensor

Yes those are the old plugs and they are not in the car anymore. All 4 plugs have been replaced. If it was the MAF sensor would the problem not be present the entire drive? I cleaned the sensor with MAF cleaner and the was no improvement.

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Do you always use the same gas/station? And were the autolites in your car previously? I know you said "equivilents", just taking stabs at it. Compression chk in order me thinks.

Yeah I second doing a compression test on your cylinders.

You can pickup a tester from CT:
Equus Compression Tester Kit | Canadian Tire

Just lookup how to do a compression test properly on this site and let us know the results.

The old plugs were oem and had NEVER been changed before. So whatever they would have been from factory. And I always use Shell premium gas but not always from the same station. And what does a compression test do? Sorry I can't really look it up right now all I have is my phone.

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Like was stated above..compression test asap.

Good luck.

Local and I changed out some plugs on his car a while back and gapped them to the cunt-hair and he had issues. He took them out and blew out the cylinders with compressed air and them put them back in, no issues since. could try this when you do the compression chk.

Could be anything but a compression chk could tell the story of that one plug.

Basically you are just screwing a pressure gauge into the spark plug hole and cranking the engine (while holding your foot to the floor to disable the injectors) and then reading what the gauge says.

An ideal reading is 180 across the board, with no more than a 10% difference between cylinders. Honestly even 10% is a bit excessive.

You'll also want to preform a wet test, since you would really be looking for bad rings most likely. This is the same as a dry test, except you put a bit of oil in the cylinder prior to cranking the engine. If rings are an issue, then typically the reading will go up a good bit when you preform the test this way.

I'd say. Did you really zoom in on that plug? Like real close?

90K those plugs still arent that bad.... I did zoom

Hey OP, did you chk the gap on the old plugs after you took em out?

I had something like this when my air straightener decided to pop out and chill in my aem dryflow filter. Short and long terms went nuts


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Okay, so if I have a bad cylinder, would that be causing my issue?

Yes, cylinder's 1 to 4 were 0.034 0.036 0.036 0.035 respectively.



On another note, just got my car back from getting looked at. There is a weak spark in cylinder 4 which seemed odd to me....but I got a new coil pack, will be arriving Tuesday and it'll get put in cylinder 4 to see if that works. If it doesn't, does anybody know where I can get a Cobb Accessport for cheaper than 600$??? I can't afford that, but at this point I need to start looking at some data logs to see what the hell is going on. I have looked about the F/S section and no luck.

If your rings are fucked yeah that could be the cause for sure.

Also that's a pretty fat gap. You want to be at .028. A gap as big as yiure got it could cause issues as well.

As far as the accessport goes they sell in VIP for ~450 all the time.

Tapa