Fuel cut

[Graveshaker]

Hello all, I recently got back into the speed3 platform after nine years of owning my first speed3. 2008 speed3, 138,000 miles the car is 100% stock but I'm able to tell that it did have modications to the exhaust and intake at one point. It's evident that the HPFP has been taken apart because of the zip tie to catch the fuel line bolt and obvious marks on the torx screws. I'm unsure if the internals have been returned to stock however.
My issue is a violent fuel cut or spark cut in fourth gear at near full throttle using two different maps. One was the Cobb stage 1 that was on the car upon my purchase and later the stage zero to mimic stock tune.

I did my best to check hoses and such when I took off the battery tray and stock intake. I did notice that the intake to turbo was very loose and easily fell off when barely touched. I initially assumed that this was the culprit and didn't bother checking spark plug gap (I know stupid) and put everything back together to realize I still had the issue. One other thing I did observe was oil pooling on top of trans directly beneath the HPFP. I'm assuming a pinched o-ring. Enclosed is a data log, any help would be greatly appreciated. datalog15.csv

[Vansquish]

If you look at your log, three things are immediately notable:

1. You are overboosting. Your car should only be hitting 15.5psi +/- about 1psi if it is on the stock tune with stock intake, exhaust, and the like. However, you WILL overboost if you run the stock tune with an aftermarket intake and/or aftermarket exhaust (particularly downpipe). Furthermore, you can end up overboosting if you run an aftermarket tune with an OEM intake/exhaust. I would strongly recommend staying out of boost until you figure out what parts are on the car or what parts aren't working properly.

2. You are hitting boost cut at line 32 of the log. You can see the injector duty cycle drops to 0, and the WGDC drops to zero starting at line 24. Your AFR is way too lean (in the 13:1 range) at 18+psi of boost.

3. You are going WOT at 2300RPM or less in fourth gear (I even did the math to figure that out from your log). This is a recipe for a blown motor.

In case you're curious, your gear ratios are:
1st - 3.538
2nd -2.238
3rd - 1.535
4th - 1.171
5th - 1.085
6th - 0.853

Main gear ratio for 1-4 gears : 3.941
Main gear retio for 5-6 gears : 3.350

Your tire height is 25.9725" (225/45/18), and circumference is: 81.595".

[Graveshaker]

Originally Posted by Vansquish If you look at your log, three things are immediately notable: 1. You are overboosting. Your car should only be hitting 15.5psi +/- about 1psi if it is on the stock tune with stock intake, exhaust, and the like. However, you WILL overboost if you run the stock tune with an aftermarket intake and/or aftermarket exhaust (particularly downpipe). Furthermore, you can end up overboosting if you run an aftermarket tune with an OEM intake/exhaust. I would strongly recommend staying out of boost until you figure out what parts are on the car or what parts aren't working properly. 2. You are hitting boost cut at line 32 of the log. You can see the injector duty cycle drops to 0, and the WGDC drops to zero starting at line 24. Your AFR is way too lean (in the 13:1 range) at 18+psi of boost. 3. You are going WOT at 2300RPM or less in fourth gear (I even did the math to figure that out from your log). This is a recipe for a blown motor. In case you're curious, your gear ratios are: 1st - 3.538 2nd -2.238 3rd - 1.535 4th - 1.171 5th - 1.085 6th - 0.853 Main gear ratio for 1-4 gears : 3.941 Main gear retio for 5-6 gears : 3.350 Your tire height is 25.9725" (225/45/18), and circumference is: 81.595".

Yes I do realize the overboosting. The car is stock with stock downpipe intake and catback. Unless the cats are gutted? It does have a K&N drop in filter but everything else is stock. I'm not understanding why its' boosting so high. Could spark plug gap cause this much of a boost increase?

[MSMS3]

Originally Posted by Graveshaker Yes I do realize the overboosting. The car is stock with stock downpipe intake and catback. Unless the cats are gutted? It does have a K&N drop in filter but everything else is stock. I'm not understanding why its' boosting so high. Could spark plug gap cause this much of a boost increase?

Short answer to your question: No, gap cannot cause the serious overboost.

Are you absolutely sure that car has a stock downpipe? The symptoms are classic for running a 3" aftermarket downpipe on a stock or stockish tune. If you are sure it's OEM, then maybe it has been gutted. You should be able to tell by smell if the car is catless. The odor from the tailpipe is distinctive and easy to identify. But, if it is a high flow catted downpipe you will still encounter the overboost problem. I'd love to see a photo of that downpipe.

What about the secondary cat in the midpipe section. Is it there? Or is there a straight "racepipe" there?

I would check gap on the plugs, but for a different reason. I've not looked at your log yet, but will this evening. If the gap in the plugs is too wide, you will get boost blow out of the spark at boost levels as high as you are seeing, even if the car is on the proper tune. Gap needs to be .026" to .028". Anything over about .032 will cause boost blow out of the spark at boost levels above stock level. Boost induced spark blow out occurs under full load beginning at full throttle, maximum load, which is well before redline. Typically at or around 4,000 rpm and full throttle. It is a hard, unmistakable cut of power followed by an attempted recovery.

You owned a Speed 3 for 9 years? Was it completely stock? Do you not know how dangerous it is to your connecting rods to got wide open throttle at below 3,000 rpm on these engines, regardless of mods and tune?

Sorry if I'm coming across too tough, but man, something is not right and you're not helping the situation. Get us some more info and stay out of the deep go pedal at low rpm.

I've now looked at the log. Vansquish is right about the injector duty cycle closing the fuel spray to protect the engine and sky high boost at low rpm. While I don't think our ECU reports injector duty cycle accurately, zero is zero. That saved your ass. You are clearly much leaner than safe. You are hitting 19.5 psi at the same time the hpfp is taking a dump.

[Graveshaker]

Originally Posted by MSMS3 Short answer to your question: No, gap cannot cause the serious overboost. Are you absolutely sure that car has a stock downpipe? The symptoms are classic for running a 3" aftermarket downpipe on a stock or stockish tune. If you are sure it's OEM, then maybe it has been gutted. You should be able to tell by smell if the car is catless. The odor from the tailpipe is distinctive and easy to identify. But, if it is a high flow catted downpipe you will still encounter the overboost problem. I'd love to see a photo of that downpipe. The downpipe looks stock because all heat shields are in place and from the bottom I can see where the support bracket is supposed to mount to the downpipe but there's actually no bracket. Mounting holes are visible. What about the secondary cat in the midpipe section. Is it there? Or is there a straight "racepipe" there? I would check gap on the plugs, but for a different reason. I've not looked at your log yet, but will this evening. If the gap in the plugs is too wide, you will get boost blow out of the spark at boost levels as high as you are seeing, even if the car is on the proper tune. Gap needs to be .026" to .028". Anything over about .032 will cause boost blow out of the spark at boost levels above stock level. Boost induced spark blow out occurs under full load beginning at full throttle, maximum load, which is well before redline. Typically at or around 4,000 rpm and full throttle. It is a hard, unmistakable cut of power followed by an attempted recovery. You owned a Speed 3 for 9 years? Was it completely stock?

The downpipe looks stock because all heat shields are in place and from the bottom I can see where the support bracket is supposed to mount to the downpipe but there's actually no bracket. Mounting holes are visible. The secondary appears stock as well.
The original tune was a stage 1 (intake and secondary decat) with this map, boost spikes where as high as 21lbs but fuel cut didn't happen as often. I wonder if I should go back to stage2 now that I secured the tube to turbo that was very loose. Maybe the stock cat (s) have been gutted.

It's been nine years since I sold my original speed3 that was modded with Sri and test pipe.

[Vansquish]

Why would spark plug gap have any impact on the amount of boost pressure your engine is able to produce? I mean, if all of your spark plugs are still firing, and you're not receiving any knock indications of knock or misfires, then your spark plugs are not the culprit.

You have a flow problem, and more specifically a flow control problem. It really does look like your overboosting because of either the tune, or the exhaust system. Are you sure, really sure, that the exhaust system, including the turbo, is stock?

[Vansquish]

Why not run a safe mode tune until you've diagnosed your car?

[Graveshaker]

Originally Posted by Vansquish Why not run a safe mode tune until you've diagnosed your car?

I thought the zero (stock) tune was safe. I only drove it the last time to obtain a log for diagnosis purpose. This speed3 is one many, many cars I own. It will not be driven until issues are resolved. But I'm at a stand still with fixes or ideas, so I logged and reached out to the community. I see you're in Metro Detroit, my hometown. I'm in Saginaw now, maybe when the weather breaks I can trailer it down to have you help me out. I'm a car guy with a lot of toys, wouldn't mind talking cars with a knowledgeable person for this platform.

[Vansquish]

Originally Posted by Graveshaker I thought the zero (stock) tune was safe. I only drove it the last time to obtain a log for diagnosis purpose. This speed3 is one many, many cars I own. It will not be driven until issues are resolved. But I'm at a stand still with fixes or ideas, so I logged and reached out to the community. I see you're in Metro Detroit, my hometown. I'm in Saginaw now, maybe when the weather breaks I can trailer it down to have you help me out. I'm a car guy with a lot of toys, wouldn't mind talking cars with a knowledgeable person for this platform.

Aw, crap. I just took a look at their website, and Cobb has apparently changed the meaning of "safe mode". The stage 0 (stock) tune is clearly unsafe for your motor. I think Cobb used to have a "safe mode" map that kept things at or near wastegate spring pressure. Unfortunately, that no longer appears to be the case.

Given that you're having some difficulty with the controlling boost, it might be worth trying a couple of things before transporting the car anywhere for deeper diagnosis. Here are some ideas, in no particular order:

1. Get under the car and check the catalysts. See if they've been hollowed out. You might be able to do this by just giving them a tap to see if there's anything inside. Or, you might have to decouple the secondary cat to take a look inside it and run something up inside the downpipe to see if the light-off catalyst is empty.

2. The stock-ish maps are clearly no bueno for your car right now. With each step up the "Stages" in COBB map terms, the tunes are designed to account for additional air and exhaust volume. Accordingly, the Stage 1 tune may target higher boost pressures than the OEM tune, but because it calls for an aftermarket intake, it has less intake restriction and may require less WGDC to achieve those higher boost values. Likewise, the Stage 2 tunes have higher target boost pressures, than Stage 1, but can achieve them more easily still because the downpipe is freer-flowing than stock. It may be that the Stage 2 map is safer for your car, but without more data, it's hard to know.

3. You might want to check and see if the wastegate arm is stuck, or if it can move. It'll be a pain in the...forearm...but you can probably snake a hand or two in there and try and move it against the spring from closed to open. Obviously only do this if the engine is off and cool You don't want to be reaching near the exhaust while it's hot!

4. Check the nipples on your boost control solenoid (EBCS) and make sure that they are in good shape. Similarly, make sure that the vacuum lines on the EBCS plumbed to the right things!

[Graveshaker]

Originally Posted by Vansquish Aw, crap. I just took a look at their website, and Cobb has apparently changed the meaning of "safe mode". The stage 0 (stock) tune is clearly unsafe for your motor. I think Cobb used to have a "safe mode" map that kept things at or near wastegate spring pressure. Unfortunately, that no longer appears to be the case. Given that you're having some difficulty with the controlling boost, it might be worth trying a couple of things before transporting the car anywhere for deeper diagnosis. Here are some ideas, in no particular order: 1. Get under the car and check the catalysts. See if they've been hollowed out. You might be able to do this by just giving them a tap to see if there's anything inside. Or, you might have to decouple the secondary cat to take a look inside it and run something up inside the downpipe to see if the light-off catalyst is empty. 2. The stock-ish maps are clearly no bueno for your car right now. With each step up the "Stages" in COBB map terms, the tunes are designed to account for additional air and exhaust volume. Accordingly, the Stage 1 tune may target higher boost pressures than the OEM tune, but because it calls for an aftermarket intake, it has less intake restriction and may require less WGDC to achieve those higher boost values. Likewise, the Stage 2 tunes have higher target boost pressures, than Stage 1, but can achieve them more easily still because the downpipe is freer-flowing than stock. It may be that the Stage 2 map is safer for your car, but without more data, it's hard to know. 3. You might want to check and see if the wastegate arm is stuck, or if it can move. It'll be a pain in the...forearm...but you can probably snake a hand or two in there and try and move it against the spring from closed to open. Obviously only do this if the engine is off and cool You don't want to be reaching near the exhaust while it's hot! 4. Check the nipples on your boost control solenoid (EBCS) and make sure that they are in good shape. Similarly, make sure that the vacuum lines on the EBCS plumbed to the right things!

This is very good information and I will do all of this in my quest for resolving my issue. I did check the nipples and hoses on the EBCS but didn't think to check if they were hooked up correctly. I guess I can look up some diagrams for proper placement.

[Jeff23spl]

i rapid way to know if the wastegate is working correctly is to disconnect the electrical wire going to ebcs. you should fall into spring boost range peaking around 11-12psi...if it keep going high, the wategate or vaccuums lines have something...

this is also an easy way to do a ''safe mode''

if you have a v3 ap, i think you can use a cobb ots map and dial back the wastegate duty yourself if the problem is from the tune. I never tried myself because i use accestuner with my own map but i read about a special process to do so on cobb website...

[Graveshaker]

Originally Posted by Jeff23spl i rapid way to know if the wastegate is working correctly is to disconnect the electrical wire going to ebcs. you should fall into spring boost range peaking around 11-12psi...if it keep going high, the wategate or vaccuums lines have something... this is also an easy way to do a ''safe mode'' if you have a v3 ap, i think you can use a cobb ots map and dial back the wastegate duty yourself if the problem is from the tune. I never tried myself because i use accestuner with my own map but i read about a special process to do so on cobb website...

Thank you, I will also try this.

[Graveshaker]

I think I may have found my issue. I'm pretty sure my hoses to my OEM EBCS is routed incorrectly to my waste gate. The hose closest to the harness is going to the tip and the one closest to the turbo is going to the waste gate. I'm pretty sure it should be the other way around but I'm unsure. Can anyone chime in? Would this cause my overboost issue?

I was able to manually move the actuator arm against spring carefully with a vice grips clamped to arm. I wasn't able to do it by hand, is this normal?

[MSMS3]

Originally Posted by Graveshaker I think I may have found my issue. I'm pretty sure my hoses to my OEM EBCS is routed incorrectly to my waste gate. The hose closest to the harness is going to the tip and the one closest to the turbo is going to the waste gate. I'm pretty sure it should be the other way around but I'm unsure. Can anyone chime in? Would this cause my overboost issue? I was able to manually move the actuator arm against spring carefully with a vice grips clamped to arm. I wasn't able to do it by hand, is this normal?

I think your hoses are reversed. I don’t have my ‘Speed any more, but look at the photo in this thread:

Help-OEM Boost Control Solenoid

But, just in case, be very gentle with the throttle when first testing to make sure this is correct, as boost is uncontrolled if they are backwards. That might be your problem.

Be very careful swapping the hoses. The EBCS nipples are plastic, very fragile, easily broken, as many here can attest.

BTW I put all my heat shields back in place after installing my catless dp, so you can’t go by presence of the shields to tell If your downpipe is OEM.

[Graveshaker]

I swapped the hoses around and took apart the secondary and noticed it is completely gutted. I will upload pictures of the downpipe. I didn't take the secondary completely out so I am unable to tell if the do has been gutted.

[Graveshaker]

**Update***
I switched the hoses leading to the waste gate the correct way, confirmed that the secondary cat is gutted and that the dp is stock (unsure if gutted). Everything else is stock. I scrolled through the tunes on the access port and found two custom tunes. One labeled "stage 1 with one cat gutted" and the other labeled " stage 1 one cat gutted and egr delete". I uploaded the first map and she drives much better but now I'm hitting 20lbs. At this point, I'm going to install my Sri, and Hpfp ordered, then get a custom tune. I won't drive it until the tune. Thank you all for your help.

[Vansquish]

Before installing the new HPFP internals, you might want to pull the pump and check what is in it now. It's quite possible that the previous owner installed Autotech or CS internals already. If you open the box on the internals you ordered, you won't be able to return them.

[Graveshaker]

Originally Posted by Vansquish Before installing the new HPFP internals, you might want to pull the pump and check what is in it now. It's quite possible that the previous owner installed Autotech or CS internals already. If you open the box on the internals you ordered, you won't be able to return them.

I'm banking on it being returned to stock because of the obvious returned to stock dp evidence and everything else being returned to stock. Especially the oil leak directly beneath hpfp housing. I purchased everything used off a well known Mazdaspeed parts breaker on Facebook.
I'm also thinking the map that's upload could have been made while those hoses was crossed. So a tune is number one priority before something goes boom. I don't think anything is mechanically wrong at this point. When I did the valve cover gasket, the inside was really clean and the chain was tight. No slap marks on the inside cover. Spark plugs looked greet with uniform burn and gap on all four. Compression tested great too.