I just had my engine rebuilt and a factory wire harness installed. First gear pulls great then from second gear on as I hit boost it bogs. I have had the car back to the mechanic so many times my wife is about to divorce me. Each time I get the car back it runs great for the drive home. The second run with the car issues begin. Anyone throw me a bone as to what could be the issue. Thanks for your time. Barz

 

ECU? CEL? Mods?

 

ECU factory stock original CEL? Not sure what that is Mods? Zero mods ....stock stock stock

 

That sounds very similar to the problem I had. I wonder if your vacuum lines have been reconnected "incorrectly" during the re-installation of your motor after the rebuild. Does your car bog around 2500~3500 rpms in gears higher than 1st?

And by "bog" I am referring to the car just suddenly stop accelerating and then you can put your foot straight to the floor and nothing will happen.

 

exactly ....makes me think. I appreciate the input and your time

 

Well try looking through the Vacuum Lines, when I did mine, the cause of that exact problem, was the fact that I used the USDM Vacuum line diagram on my JDM car, then I discovered the differences, because I rushed it a little. When I used the "correct JDM vacuum diagram" it resolved my problem.

Definitely take a look at your vacuum lines, I would start there.

There is a difference between the JDM and USDM vacuum diagrams. the key thing to look for is, the JDM Engines will have 3 pass through vacuum ports on the Lower Intake Manifold, if you see 3, you have a JDM motor, and you should use the JDM Vacuum line diagram specific for your car, if you have 4, It's USDM, so use the USDM Vacuum line diagram instead. Keep this in mind so you won't repeat my mistake.

 

Mods= modifications
CEL = Check Egine Light...do you have one?

Do you have a boost gauge? If so, what do you see on the gauge? Can you be more specific with what you mean by “bog”? And at what rpm does it happen?

With the info you’ve given it could be anything from a lazy or sticking actuator, solenoid or something as simple as a leaking coupler.

 

No boost gauge, coming out of first gear two second there seems to be no issue, if i gradually accelerate the rpm threw 5000 all is well. The key word is gradual acceleration. The issue is once i try and kick in the turbo's my teeth nearly hit the steering wheel as it completely dies. I have tried to hold the peddle down but its like its chocking and continues to chock until I back the peddle off,.

 

A boost gauge would assist as this to me sounds like your over boosting, and getting boost cut.

 

Getting a boost gauge is a very good idea, it will give way more information.

From my experience with this same issue on my car, I got around 2psi of boost, also, my car struggled to get above 6600 rpms, as it just doesn't want to go any higher.

When i looked through my vac lines an corrected the routing, boost was restored an my car no longer bogged down.

 

Ive had something similar happen... Noticed it was over boosting and would cut fuel (bog and wouldnt accelerate under heavy throttle) there is a little niple way under on the bottom of the wastegate that the vacuum line came off.
Took a while of diagnosis to even realize there was one there.

 

I had similar issues with my R1 almost exactly as you describe. Mazda dealer who installed my reman motor could never figure it out nor the mazda dealer near me who serviced the car years ago. From my searching the forum I suspected the charge relief solenoid. However I was never able to confirm that was the issue as I went single turbo after doing some other mods. Might be a start for a search or others can confirm if this would cause your issue.

 

Another small diagnostic note is each time I picked up the rx from my mechanic the car showed zero signs of hesitating / bogging when the motor came up to the turbos kicking in. I could drive it for a hour shut it off get back in and drive it again later that day still no issues. I would leave it for a few days and the problem would raise its ugly head. I would return the car and the vicious cycle would repeat. This is when the new wiring harness was added and again it ran great for a day of drive then it went back to running like crap!

 

It sounds like a sticking solenoid or a leaking vacuum line to me. Do you get any fluttering noises when the "bog" occurs?

 

Limp Mode?

Check for CEL codes

 

Yes, yes I do. I was so frustrated a held the accelerator to the floor and it fluttered for sure.

 

Now I think about it I lied its all stock. The cat converters were trash so my mechanic dropped them for for a through pipe... any relation to my issue perhaps?

 

I was told the bogging issue was related to my exhaust, so I disconnect it and ran the car with the same issue. I did notice I could not hold a consistent RPM in first gear, I held the gas peddle trying to hold a 2000 /2500 rpm and all it did was surge. It surged from a two second constant to a higher rpm then down held constant then back to a higher rpm then down.

 

Get a boost gauge. If you opened your exhaust up the it's quite possible that your fuel being being cut. If you put your cat back on your problem will most likely disappear.

 

Eliminating the cat could be enough to reach fuel cut. Does it have an aftermarket intake filter or anything?

It sounds like a bad vacuum solenoid to me. The rats nest is the woes of many a FD owner. Wonder if the guy on here is still selling new ones? There is a thread on how to remove your solenoids and check them by baking them in the oven and using a mighty vac, vacuum gauge. If you decide to do this and are going to use an old psu from a pc, pm and I can send you a wiring diagram to bypass the safety for the 12v rail to power on.

Maybe try a different rotary shop? There is a list in the Canadian forum for other shops, you’ve probably seen it?

There is also a gate or something on the turbos that I’ve heard of several people mention was sticking on their FD’s, causing similar issues to what you describe.

Dirty fuel injectors maybe? Bad grounds? Bad coil pack?

So many possibilities, with these cars it’s difficult to say with out access to it really. Good luck, you’re gonna need it.

Edit

How many miles are on the car?
What maintenance has been done?
New fuel filter, could be stopped up?

 

I still have my suspicions that there something wrong vacuum line related.

 

This makes it sound like it is your turbo control solenoid (I believe it is part # N3A1-18-741) under the upper intake manifold. It is behind the twin solenoid piece there. It's either cracked or is not getting the appropriate vacuum/boost reference.

I highly suggest you take it to a rotary mechanic and have them go over entire the vacuum system as it is likely in need of service and is not a fun job to do.

 

Update,
I think I found the needle in the haystack, well not me but my mechanic. Will re and re the wiring harness and then cross my fingers for a new beginning for a new rebuild performance satisfaction