Hiccup under full throttle.

[withcheese]

So I haven't had a chance to do an all out run with the car. Today I did and when I hit 4th gear at about 4000RPMs I felt a hiccup, and it is in all gears. I know the AF gauge is showing that I am running lean not to bad but I'm not is the "good" running part of the gauge. Tomorrow I will take out the plugs and see what they look like. Any thoughts would be great thanks.

[kamon8404]

I suppose that you have a narrow band af gauge.

What do you mean by hiccup?

[withcheese]

I guess studder would be a better way of discribing it, it just seems like its missing when you hit a certain rpm, its not smooth you hit that rpm and the car kind of lets go and comes back on but its fast.It could be the motor dumping fuel in to the cylinder? It's hard to describe and not show you know.

[SleepyMSP]

welcome to hesitation...it hits you around 4500 RPM and WOT, too much fuel gets dumped into the Cylinder...one of the many loving qwirks the Mazda Engineers gave us MSP owners

[withcheese]

So would an ems or split second afc help this problem?

[Knox Joe]

Yes.

The AFC would be great if you're just doing light mods, or just want to fix the hesitation from the stock ECU tune.

[withcheese]

Welp got two things on my birthday list XD.

[ForceFed]

Yup...
Welcome to the wonderful world of MSP issues.
This is one of many I am sure you will find upon your journey to the land of Zoom Zoom.

[SleepyMSP]

This is one of many I am sure you will find upon your journey to the land of Zoom Zoom.

LOL, well put

[jdwk]

I just posted about this exact problem in the tech, perf, fi section. Mine was incredibly bad this morning, I couldn't even get past 4.5k rpms. Yet, it was fine in the afternoon on the way home from work.

I would prefer to get rid of this problem without resorting to aftermarket fuel control. Since the problem comes and goes, there must be a reason for the car to dump fuel or not to. Also, I didn't have it all for the first 1.5 years I've had the car, so something has changed.

[SleepyMSP]

I just posted about this exact problem in the tech, perf, fi section. Mine was incredibly bad this morning, I couldn't even get past 4.5k rpms. Yet, it was fine in the afternoon on the way home from work.

I would prefer to get rid of this problem without resorting to aftermarket fuel control. Since the problem comes and goes, there must be a reason for the car to dump fuel or not to. Also, I didn't have it all for the first 1.5 years I've had the car, so something has changed.

If you can't get past 4.5K that sounds more like fuel cut, hesitation will slow your progress through the power band at that point...if your hitting fuel cut there is probably an issue, boost/vac leak or loose pipe of some sort...

[brmiley]

I have a heavily modded MSP with primary and secondary fuel rails and injectors..mine does the same thing and it seems to be during cold times like everyone says. but yet it does it when its warm too....im getting it tuned again real soon and hopefully it clears up this problem...whats the main fix for this other then that? i heard so guy talking about a special order from mazda for your WGA...should i get a fuel cut preventor? any help..

[jdwk]

I don't think it's a leak or a loose pipe, since it was fine on the way home and fine again in the way into work this morning.

[SleepyMSP]

I have a heavily modded MSP with primary and secondary fuel rails and injectors..mine does the same thing and it seems to be during cold times like everyone says. but yet it does it when its warm too....im getting it tuned again real soon and hopefully it clears up this problem...whats the main fix for this other then that? i heard so guy talking about a special order from mazda for your WGA...should i get a fuel cut preventor? any help..

I'm assuming with the dual injector setup you are running some kind of EMS? If so just retune it for the amount of fuel you are now pushing into the cylinders

[SleepyMSP]

I don't think it's a leak or a loose pipe, since it was fine on the way home and fine again in the way into work this morning.

Do you have a boost/Vac gauge? what is it reading at idle and what are you boosing?

[ogsp5]

The SS afc is the best value for this situation. When I installed mine and after many hours of data logging and dyno tuning that hesitation is gone.

[jdwk]

The car is pretty much stock except for motor mounts (lots of vibration), and an Injen CAI (super loud turkey), so I don't know exactly know how much boost I am seeing. I'm sure it's in the 6-7 range.

I filled up again last night (this is getting expensive). The car got 26mpg once again on the QT 89, even with all that hesitation. The last tank of 91 I used got me 22 mpg. I guess I've been doing a little more highway, and the weather is warmer than it was 2 tanks ago, but 20% seems like a lot.

Despite the ridiculous 3.44 per gallon I used 91 this time at Chevron. I felt a tiny rumble this morning just once, but was fine after that. Nothing as bad as Mon morning. I guess the only permanent solution is an EMS, but that will only lead to boost controllers, hard pipes, FMIC's, BOVs, etc and quickly gets very expensive, when this was supposed to be my daily driver.

[SleepyMSP]

The car is pretty much stock except for motor mounts (lots of vibration), and an Injen CAI (super loud turkey), so I don't know exactly know how much boost I am seeing. I'm sure it's in the 6-7 range.

I filled up again last night (this is getting expensive). The car got 26mpg once again on the QT 89, even with all that hesitation. The last tank of 91 I used got me 22 mpg. I guess I've been doing a little more highway, and the weather is warmer than it was 2 tanks ago, but 20% seems like a lot.

Despite the ridiculous 3.44 per gallon I used 91 this time at Chevron. I felt a tiny rumble this morning just once, but was fine after that. Nothing as bad as Mon morning. I guess the only permanent solution is an EMS, but that will only lead to boost controllers, hard pipes, FMIC's, BOVs, etc and quickly gets very expensive, when this was supposed to be my daily driver.

ok, a few things:

1. never use under 91 octane...ever
2. get a boost gauge...it will help you diagnose problems 1000 times easier
3. check the WGA it could be shot
4. you can just get a SS AFC and that will cure the problem if point 3 isn't the problem

[Knox Joe]

Yeah, you using the wrong gas is your problem. Cut that out now.

Premium only, or get a different car.

[jdwk]

I doubt the hesitation has anything to do with the octane of the gas. All octane allows you to do is advance timing further before knocking. And since the problem manifests itself at a very specific rpm and in cold weather, pre-detonation is an unlikely candidate.

You can't possibly think that Mazda tuned these cars to the brink (think leaned out fuel and advanced timing) that you can't run on 89. Yeah, the car may pull some timing, but on our cars, you're probably losing 2-4whp. We are running 6 to 7 psi stock, and running insanely rich at that. If people want to save $2.40 per tank and sacrifice a couple ponies, I really don't see a problem. Mine was more of an experiment since I first noticed the hesitation on 91.

Unless there is a bunch of evidence that suggests the 4.5k rpm hesitation is octane related, I would most likely go with the information in the sticky that it is an overly lean condition brought on by poor fuel maps. However, the reflash did not fix mine, unless the dealership never actually reflashed it, which is a possibility of course.

[Knox Joe]

I doubt the hesitation has anything to do with the octane of the gas. All octane allows you to do is advance timing further before knocking. And since the problem manifests itself at a very specific rpm and in cold weather, pre-detonation is an unlikely candidate.

You can't possibly think that Mazda tuned these cars to the brink (think leaned out fuel and advanced timing) that you can't run on 89. Yeah, the car may pull some timing, but on our cars, you're probably losing 2-4whp. We are running 6 to 7 psi stock, and running insanely rich at that. If people want to save $2.40 per tank and sacrifice a couple ponies, I really don't see a problem. Mine was more of an experiment since I first noticed the hesitation on 91.

Unless there is a bunch of evidence that suggests the 4.5k rpm hesitation is octane related, I would most likely go with the information in the sticky that it is an overly lean condition brought on by poor fuel maps. However, the reflash did not fix mine, unless the dealership never actually reflashed it, which is a possibility of course.


You can't be serious, right?

Okay, you're right, run whatever gas you want. I mean Mazdas engineers have no clue what they're talking about. (ugh) There's no reason they put "premium only" right on the gas door.

If you seriously think this, I'm done helping, you're beyond help. (encourage

I didn't think people were this stupid.

[jdwk]

What technical basis do you have for thinking that 89 causes the hesitation? That's all I am asking for.

How much dyno tuning have you done?
I'll admit I haven't done any with the Protege, but I have done quite a bit with my other car, which although NA is 10.9:1 compression and its manufacturer recommends 93. I own HP Tuners and can actually see the knock sensors trip and pull timing if I advance it too far. But you can't hear or feel it, the sensors are too sensitive and too quick. And probably the biggest factor in how far I can advance is IAT, not how much 101 I mixed in.
Since I am experiencing the hesitation more in colder weather, I'd say it's not knocking from the low octane gas. And I will reiterate, the hesitation started on a tank of 91. And this morning it was really bad, 70 miles into a fresh tank of Chevron 91.
Since all you can tell me is to not use 89, when I have already ruled that out as possible culprit, then I really don't want your help.

[SleepyMSP]

I don't think the octane will cause the hesitation but I think he is just trying to say that its better to put in 91+ to avoid any problems. Personally like I said above, check the WGA and if its fine then its just the stock mazda tune that we all are stuck with. way to many people have hit this, if you had a wideband on you'd see how rich the a/f ratio gets at that point...

[shawn83gt]

I only use BP gas in my car. It runs like crap on any thing else. I have tried shell v-power, no good. Only BP. Don't know why just the way it is.

[Velocifero]

FYI, to check your WGA, find it (topside between turbo and head) and follow the vac line up til you hit a Tee (directly above tranny on driverside, right next to the head) where one branch goes to the BPV and the other to the IM. Disconnect the WGA end of that vac line and blow into it. If any air passes through then the diaphram is shot and you would do well to order the ATP replacement as it is alot cheaper and you'll gain ~2psi. If you meet ridiculus resistance then the diaphram is fine and you'd still probably be better off replacing it as it will fail at some time. PM me if you need any more help with this issue.

[Velocifero]

I only use BP gas in my car. It runs like crap on any thing else. I have tried shell v-power, no good. Only BP. Don't know why just the way it is.

werd, I only use BP and QT but I feel the car runs better on BP

[SleepyMSP]

werd, I only use BP and QT but I feel the car runs better on BP

sorry off topic here, BP/QT??? remember Canuk...

[Velocifero]

sorry off topic here, BP/QT??? remember Canuk...

BP is a gas station, stands for British Protroleum
QT is a gas station, stands for Quick Trip


both the signs for said gas stations just use the initials.

[SleepyMSP]

BP is a gas station, stands for British Protroleum
QT is a gas station, stands for Quick Trip


both the signs for said gas stations just use the initials.

oh...LOL (stooges)

[Knox Joe]

What technical basis do you have for thinking that 89 causes the hesitation? That's all I am asking for.

How much dyno tuning have you done?
I'll admit I haven't done any with the Protege, but I have done quite a bit with my other car, which although NA is 10.9:1 compression and its manufacturer recommends 93. I own HP Tuners and can actually see the knock sensors trip and pull timing if I advance it too far. But you can't hear or feel it, the sensors are too sensitive and too quick. And probably the biggest factor in how far I can advance is IAT, not how much 101 I mixed in.
Since I am experiencing the hesitation more in colder weather, I'd say it's not knocking from the low octane gas. And I will reiterate, the hesitation started on a tank of 91. And this morning it was really bad, 70 miles into a fresh tank of Chevron 91.
Since all you can tell me is to not use 89, when I have already ruled that out as possible culprit, then I really don't want your help.

You don't get it.

It's kind of hard for us to help you diagnose the problem if you're adding a really stupid variable into the equation.

A hesitation usually isn't fuel cut, fuel cut is abrupt, and you'll know when you hit it.

The hesitation you have is hard to diagnose because you have no idea what your turbo is doing, because you didn't install a boost gauge.

Also, I have helped a few other people diagnose problems on here, and fix them, I also have done basically everything you can to this car, but hey if you don't want my help...

[MX5RACER]

I will second the comment on running 91+ octane. You really need to run the good stuff in a turbo engine. The number one reason is detonation resistance. In a N/A car, it will only ping when you run into detonation issues, but with F/I you can melt the pistons and even shatter rods with detonation.

I am not saying that this is the absolute cause of your issue, but it is a good preventative measure. Also, when you are talking about a F/I car, remember that cold air helps the turbo/supercharger, by raising the amount of oxygen in the intake charge. So with more oxygen/cubic yard of air and the same amount of fuel, you will run lean.

One other point is that if your car is not running on the correct octane, the computer will compensate and lower the timing or add fuel. Both of these conditions can cause the car to feel sluggish.

The Wastegate actuators are a hugely know problem as well.

[FunkyCold5]

I actually have the same exact problem. It's not hesitation. I've owned my car since new (2003) and this is the first time I've had this issue. It started November/December when the weather started getting colder, but I just figured it to be fuel cut. Since I have an Injen CAI, I figured too much air was going through the MAF and cutting the engine. It would always jerk at the 4500 mark sometimes at the 3500 mark if I put the pedal to the metal.

I didn't think anything of it. During warm days, I didn't have the issues. Turbo kicks it at the right time and all is good, BUT would always have the same issue once the outside temperature goes down.

A few weeks ago, my turbo started boosting late. It would spool past 4500 and kick in at 5500-6000, and when it kicks in IT KICKS in. I've never felt that much umph in my car EVER!

Two days ago, my CEL came on when I was accelerating on a merge. I was coming home late at night, too, so I was freaking it'd break down on me in the middle of the parkway.

Anyways, took to to Mazda yesterday and today I get a call back from my rep. He said the diognostic came back with a leak in the gasket manifold. I believe he said my car was running too lean and the gasket is leaking. He said it corroded from the heat of running lean for a prolonged time.

SOOOOOOO, if you have the same issue as mine, try to fix it or else you'll be paying $459 for parts and labor.

Andrew

[jdwk]

Didn't get a chance to test out the WGA yet. That is a good idea, I will try it out tonight.
The hesitation was really bad this morning, but it's definitely not any fuel cut. The car will continue through the hesitation (rumbling, poor acceleration), until right at 5k rpms, it smooths out and pulls as hard as ever.
Sometimes it'll just be one little stumble around 4k, sometimes it stumbles from 4k all the way to 5k. This morning was more of the latter.
I also tested holding my foot at half throttle through the same band, and there was no hesitation. I think that makes it seem a little more like the fuel maps. I'll let you know when I get around to the WGA test.

Thanks for the replies.

[SteelWarrior]

I would like to point out that in Winnipeg Manitoba (Canada for all you Americians that dont have world maps :P JK) that where one of the cheapest provinces in the country and I am paying 1.30/L atm. which if im not too rusty is a hell of alot cheaper then waht most of you pay per gallon...basically filling my car on premium costs me 70+ dollars usually.....the way i choose to see it, is my car costs me like 600 a month with insurance, if i cant afford to pay 70 bucks a tank i shouldnt have bought the car, especially with how much i boost and drive it hard which obviously doesnt help millage.....i choose to see gas as a nessasity and therefor it doesnt bother me that i pay so much haha

[SleepyMSP]

I would like to point out that in Winnipeg Manitoba (Canada for all you Americians that dont have world maps :P JK) that where one of the cheapest provinces in the country and I am paying 1.30/L atm. which if im not too rusty is a hell of alot cheaper then waht most of you pay per gallon...basically filling my car on premium costs me 70+ dollars usually.....the way i choose to see it, is my car costs me like 600 a month with insurance, if i cant afford to pay 70 bucks a tank i shouldnt have bought the car, especially with how much i boost and drive it hard which obviously doesnt help millage.....i choose to see gas as a nessasity and therefor it doesnt bother me that i pay so much haha

yeah your lucky being in the mid-west there, over here in QC were getting it in the ass...I'm up to 750/month for the car, it hurts...

[Spooler]

Hey folks,
I'm new to this forum, so I have a lot of catch up to do. I had the same problem two years ago. Under full throttle, the car would loose all of it's power at 4000 RPM (pretty nasty decelaration, not very good for the car...). My dealeship found that there was a hole on the vaccum line (after 4 days.....) that goes from the engine to the tubo. They cut the line where the hole was and added a fitting in between....not very elegant, they should have changed the line, but it fixed the problem. So I suggest a leak test...

[brmiley]

I'm assuming with the dual injector setup you are running some kind of EMS? If so just retune it for the amount of fuel you are now pushing into the cylinders

Yeahh..Its actaully down at Modern Performance Inc. In New Jersey, USA...hes a mazdaspeed mechanic..last i hear from him..your car runs like shit, i think its going to need more then tuning...hopefully not to expensive this god damn car has cost me enough now with all the mods and brakes happening.