I own a 93 Fd stock and when i accelerate my car bogs out on 4500 rpm, it stalls and the acceleration does no more this happens ever gear. I took it to Mazda Dealer, they told me 1 of my rotor is low on compression and i was wonding if the low compression is causing this lac of acceleration?

Thanks guys.

 

Depending how low the compression is, yes this could be the problem. However, the fact that it's 4500rpm plus suggests you might also have a turbo control system issue (not the turbos, but the solenoids and actuators that valve the boost).

The dealer is usually trustworthy to provide the compression test you've gotten so far. For more info on compression read the 3rd gen faq linked at the top of this forum.

For your next step I recommend you find a good rotary shop. Let them retest it and give you an estimate for a rebuild.

Dave

 

quote from "For your next step I recommend you find a good rotary shop. Let them retest it and give you an estimate for a rebuild.

Dave"

that would be for the best

 

Only if it needs it. If the dealership is going to say something like low compressioon casues it to lose power at XXXX RPM then you should not be trusting them for ****.

typically a low compression engine makes more power as the RPM climbs as the sealing losses are not so apparent at higher RPM's. (thatas why a low compression motor is hard to start, but once running seems to run somewhat OK)

That is also why when you do a compression test the factory gives you an exact RPM to test at. from my experience just varying the RPM by more than a couple of hundred RPM is enough to give really bad readings, simply not depressing the accelerator during the test will drop you by 30~40 psi....

So while I am not discounting that it might need a rebuild, I would lean towards the rats nest having a vacume leak or a bad solinoid. hence you need to find a rotary specialist shop to look at the rats nest, or get a vacume diagram and start troubleshooting it yourself depending upon your experience level.

kenn

 

Exactly, look at all the solinoids first, or could be as simple as needing a vac hose job. Best advice already given is to find a good rotary shop.

 

I had a similar problem and it was a clogged fuel filter. Most noticable going uphill.

 

another question? if i have low compression would i still pass smog?

thanks

 

I had a promblem with a low cempression rotor asswell but I dint have such promblems. The only promblem I had is that the car didnt start up easily

 

my car doesn't have any problem starting up. The mazda dealer keep saying i have a misfire?

 

do fd's have secondary throttle plates like fc? I had the same problem with my fc and the secondary throttle plates werent opening, the car would just buck and stall over 4k with no boost. I wired them open and the car was a monster, accelerated to the buzzer every single time.

It could also be your wastegate actuator like was mentioned.

 

it's been mentioned earlier in the thread, but i'll reinforce it. i suspect if low compression was primary issue, your primary complaint would have been difficult starting as opposed to losing power and stalling at 4500 RPM. so i agree that though confirming the compression is important, but you'll probably be best served looking at the turbo-related reference lines and such before condemning the motor itself right now.