Slight Hesitation when Accel on HWY.

S

sierra248

Contributor
:
2007 MazdaSpeed3
Been awhile since I've posted, but I been keeping up on things. When the car runs great, you dont b**** much I guess is why I haven't been around, But.. Pretty much since I've had my car, when in 6th gear while cruising at HWY speeds, if I step on gas, there is a slight hesitation before she moves out, its very slight, but I've always wondered about it(Its also not consistent and happens rarely). My car has always run so well and the only time I've taken it to the dealer was for the Engine Mount Bolt. I hate dealers so I avoid them like the plague but I am one of the VIN numbers for the Fuel Pump TSB which I've never gone and got the flash or a new pump. My car for just a COBB SRI has run in the 13's with a best of 13.6, and I've only been to track twice with it, so she is kind of a freak, which is why I've yet to take it to the dealer for the Fuel Pump TSB. What you guys think, anyone evr experience this. I thought I'd read about it awhile back but I cannot seem to find it.

Thanks for any help,
Tom
 
Last edited:
If you are at legal highway speed, you should be in fifth. If you're running 80, then sixth is about right, fifth will really jump. It's kinda the "passing gear" for that speed. I suspect you're experiencing "turbo lag", but someone who leans on their car more than I can jump in here.
 
I am by no means an expert but that is definitely turbo lag. In 6th gear you should never be going WOT or even 3/4, personally I rarely give it more than 1/2 throttle. It puts significantly more load on our little 4-banger. If you need to pass somebody going 80, switch to 5th. When boosting in gears 5 and 6 wait until you are at least past 3.5-4k rmps in order to give it the beans. The only time ive gone WOT in 6th gear is when I am going at least 100mph, at a track or course.
 
Its not turbo lag and your wrong about running 65-70 in fifth, you should be in 6th. I run 6th at 50 MPH on my way home(40 Miles each way all the time and if I need to make a light, I'll floor it sometimes without downshifting, yes boost spikes to 20 or so and very quickly gets back down to 15-16 as it should be. Happens to almost all turbo cars and 50 in 6th is probably the equivalent of 25 in 3rd, you never do that either? Unless your crazy modded, enjoy your cars and worry bout the problems as they arise. Driving around on the highway in 5th gear with a motor mount is quite noisy and rough, slide it into 6th fellas. Now anyone have any ideas about my problem, the fuel pump TSB doesn't sound like my problem but maybe?

Due to low fuel pressure at the high-pressure fuel pump, some vehicles may experience the following:
Rough idle, stall, and/or hesitation under cold conditions.
Intermittent lack of power during acceleration when the engine gets hot.
MIL turns on with DTC P2177/P2187 (fuel system too lean at off idle).

It happens when hot also.
My engine never really gets hot, I live in Florida and run water and water Wetter only, shes nice and cool.
I've never thrown a CEL

Also this has happened when I'm cruising at 90-100 miles per hour and get on it to pass or something, Turbo Lag aint happening to our engines at those speeds, I dont care what gear your in. Seems to only happen after long streches of cruising or cruise control on and I step on it.
 
I've had the same problem for sometime now, took it in to the dealer and they can't figure it out, so I gave up. When it happens the DH logs KR to 7.5 and it feels like your motor hit a wall for that sec, I just deal with it even with my tune now it still happens. I can kinda tell when it will happen so I let off the gas for a sec, drop the rpm then give it the beans and no problems at all. Sad that I have to do that, but when KR reads I generally let off the gas, don't need the speed to go boom boom.



sierra248 said:
Been awhile since I've posted, but I been keeping up on things. When the car runs great, you dont b**** much I guess is why I haven't been around, But.. Pretty much since I've had my car, when in 6th gear while cruising at HWY speeds, if I step on gas, there is a slight hesitation before she moves out, its very slight, but I've always wondered about it(Its also not consistent and happens rarely). My car has always run so well and the only time I've taken it to the dealer was for the Engine Mount Bolt. I hate dealers so I avoid them like the plague but I am one of the VIN numbers for the Fuel Pump TSB which I've never gone and got the flash or a new pump. My car for just a COBB SRI has run in the 13's with a best of 13.6, and I've only been to track twice with it, so she is kind of a freak, which is why I've yet to take it to the dealer for the Fuel Pump TSB. What you guys think, anyone evr experience this. I thought I'd read about it awhile back but I cannot seem to find it.

Thanks for any help,
Tom
Click to expand...
 
sierra248 said:
Its not turbo lag and your wrong about running 65-70 in fifth, you should be in 6th. I run 6th at 50 MPH on my way home(40 Miles each way all the time and if I need to make a light, I'll floor it sometimes without downshifting, yes boost spikes to 20 or so and very quickly gets back down to 15-16 as it should be. Happens to almost all turbo cars and 50 in 6th is probably the equivalent of 25 in 3rd, you never do that either? Unless your crazy modded, enjoy your cars and worry bout the problems as they arise. Driving around on the highway in 5th gear with a motor mount is quite noisy and rough, slide it into 6th fellas. Now anyone have any ideas about my problem, the fuel pump TSB doesn't sound like my problem but maybe?

Due to low fuel pressure at the high-pressure fuel pump, some vehicles may experience the following:
Rough idle, stall, and/or hesitation under cold conditions.
Intermittent lack of power during acceleration when the engine gets hot.
MIL turns on with DTC P2177/P2187 (fuel system too lean at off idle).

It happens when hot also.
My engine never really gets hot, I live in Florida and run water and water Wetter only, shes nice and cool.
I've never thrown a CEL

Also this has happened when I'm cruising at 90-100 miles per hour and get on it to pass or something, Turbo Lag aint happening to our engines at those speeds, I dont care what gear your in. Seems to only happen after long streches of cruising or cruise control on and I step on it.
Click to expand...

First question - what mods do you have?

I find the car hesitates slightly at anything under 3K RPMs. And you should not be in 6th until 60+, unless you enjoy the extreme pressure being put on your rods for longer periods of time during the combustion cycle. IMO it's more due to turbulence in the intake chamber and the associated MAF readings. A RMM will only magnify the effect.

You might check the fuel injectors and throttle body for buildup. Otherwise try increasing your RPMs and see if that changes the frequency of occurrences.
 
sierra248 said:
Its not turbo lag and your wrong about running 65-70 in fifth, you should be in 6th. I run 6th at 50 MPH on my way home(40 Miles each way all the time and if I need to make a light, I'll floor it sometimes without downshifting, yes boost spikes to 20 or so and very quickly gets back down to 15-16 as it should be. Happens to almost all turbo cars and 50 in 6th is probably the equivalent of 25 in 3rd, you never do that either? Unless your crazy modded, enjoy your cars and worry bout the problems as they arise. Driving around on the highway in 5th gear with a motor mount is quite noisy and rough, slide it into 6th fellas. Now anyone have any ideas about my problem, the fuel pump TSB doesn't sound like my problem but maybe?

Due to low fuel pressure at the high-pressure fuel pump, some vehicles may experience the following:
Rough idle, stall, and/or hesitation under cold conditions.
Intermittent lack of power during acceleration when the engine gets hot.
MIL turns on with DTC P2177/P2187 (fuel system too lean at off idle).

It happens when hot also.
My engine never really gets hot, I live in Florida and run water and water Wetter only, shes nice and cool.
I've never thrown a CEL

Also this has happened when I'm cruising at 90-100 miles per hour and get on it to pass or something, Turbo Lag aint happening to our engines at those speeds, I dont care what gear your in. Seems to only happen after long streches of cruising or cruise control on and I step on it.
Click to expand...

Yea I will be in 6th gear below 60 mph for better mileage, I just dont floor it because of said pressure being put on rods like in the above post.

Like I said im no expert, but I thought that turbo lag was the amount of time between you flooring it and the turbo spinning up to full boost. Im pretty sure that this can happen at any speed as it is based on throttle and not the speed in which you are going.

I have a 2007 MS3 thats stock except for an sri and have had the TSB for the fuel pump done as it is a requirement in California for emissions regulations. The problem that you are describing I have as well. Whenever I give it increased throttle in 5th or 6th at low rmps I definitely experience some lag or lack of power until I get beyond approx 3k rpms and boost spikes
 
Get a TIP to go with the SRI or CAI, turbo will spool much quicker at low RMP. I woud be easing into the boost too though, IMO.
 
What is a TIP? Sorry I really dont know. I'm guessing its something for the intake? I have the Cobb SRI.
 
TIP= Turbo inlet pipe.. Where do I see if I'm on the recall list for the fuel pump. I have some mods and do not want any isssues with fuel.
 
I need to remove my Battery box soon anyway as the bolt under it that holds the intake bracket is gone? May have to check out a Turbo Inlet Pipe, I'm pretty sure its an easy install if battery box is removed. Here is the TSB:
 

Attachments

  • fuel pump TSB.pdf 5-20-08.pdf
    101.7 KB · Views: 99
I think Cobb makes an inlet to go with their SRI's, its more expensive tho and doesn't look as good as the PG one IMO. Do a search on here, there's plenty of discussion on fitting and how to install but with the right set up and tools it shouldn't take you more than an hour and a half and there is a noticeable difference for a $100 on the PG one.
 
sierra248 said:
I need to remove my Battery box soon anyway as the bolt under it that holds the intake bracket is gone? May have to check out a Turbo Inlet Pipe, I'm pretty sure its an easy install if battery box is removed. Here is the TSB:
Click to expand...


Thanx Man.. Inlet is my next mod after fuel pump.
 
You can be in 6th at 50+ mph.....just down shift to a lower gear if you need to get on it quick!!!!
 
Yup, checking out an inlet for mine also. I do like the fact that Cobb makes it in Black though, dealer probably wouldn't even notice for any warranty work.
 
Last edited:
Thanks, I been thinking bout pulling the plugs and replacing them, I'll probably do that when I do the Turbo Inlet hose. See if I can get this cleared up. It bothers me so rarely that I'm not terribly worried bout it but it is a little annoying. I'm wondering if a Catch-Can is something else I should do to limit the smoking turbo upon heavy accel?
 
These our stock plugs? I only have 28,000 miles so I doubt thats it but hey you never know.

NGK Laser Iridium ILTR6A-8G
 
Please log in or register to reply here.

Similar threads

C
2002 Protege5 Rough Idle, No Power/Acceleration
Replies
9
Views
2K
Cosmas
C
M
Stuck With 2002 Mazda Protege Hesitation and Now Idle Shaking
Replies
3
Views
2K
Matt.M2
M
S
Need guidance on purchasing a used MS3
Replies
0
Views
4K
speedyspaghetti
S

Latest posts

Back