Hey guys. I recently replaced my fdp that was leaking. When I replaced the fpd I also replaced all of the vacuum lines, and spark plugs. I have check the routing on all of the vacuum lines several times and I have checked to make sure that the proper plug wires is going to the current plug and coil. When the car is under any sort of a load it bogs really bad. the idle is perfect as well as vacuum on my gauge. Everything ran fine before all of this. I just can not figure this out. Do yall have any suggestions?

 

If your fpd was leaking then it definitely wasn't running fine before. If you took a bunch of stuff off and put it back and now it's doing what it wasn't before, then that means you missed something. Take it all back apart and check again. There are too many variables for us to really guide you considering how much you changed.

 

+1 above. I did my rat's nest (assume you are running twins) and double checked everything. Still missed something (forget exactly what)

Also check your check valves are in the right direction. TPS?

Other than that, could be bad solenoids or actuators, but think those only come into play on transition.

It could also be fuel starvation. Is the FPD on correct. Anything you could have upset changing that?

 

It did run great when I put it in my shop 4-5 months ago. I started it for the first time after it was stored and that is when it started to leak. I made sure that the correct solenoids are in the correct places. I have checked over all the vacuum lines 5 or 6 times and removed the rats nest again. The TPS has the proper voltage, I already checked that. All of the check valves are installed correctly and they are Viton. I was also wondering if it was fuel starvation. I bought a new fuel filter and a fuel pressure test kit. I may use the fuel pressure tester if I still cant figure this out. Yes it is twins.

 

If you have a pressure tester, go ahead and check that first. And check it while increasing revs to the point of bogging down

 

I used the fuel pressure tester and fuel pressure dies not drop when it bogs. It will only bog when it reaches operation temp.

 

That's useful info. So it fully revs when it's cold?

So are you saying FP completely dies when it bogs, that it doesn't just drop, but goes to 0?

 

It fully revs when cold and also when hot. Just under a heavy load like depressing the throttle pedal to the floor.

It does not drop. I misspelled and wrote that is dies not drop. my grammatical error.

 

Does it bog when getting into boost or just regular driving? Is it building any boost at all?

Dale

 

It does not bog under regular driving. It will show around 4-5 lbs of boost before it bogs. it will also bog while just revving with a heavy load.

 

Check your secondary injectors. I had a friend's FD that idled and revved fine but would bog down under load. One of the secondary injectors was totally dead, I think it was open loop when testing the resistance on a multimeter. Could also be one of the plugs for the secondary injectors is broken or not plugged in all the way.

Dale

 

They are plugged in correctly, but I may put my multimeter on them to check. I am going to reinstall the factory ecu and see what all error codes I get.

 

So does it bog under the same conditions (load) hot and cold, or just hot (you mentioned it only bogs hot earlier)

If it's only bogging when hot, not sure it's your injectors. Sounds like it could be a control issue somewhere

Fuel Temp Sensor?
Water Temp Sensor?

 

It only bogs when its hot.

 

Are you able to read AFRs?

 

No I am not. It does smell rich when it bogs.

 

Injector (likely secondary) sticking open when hot?

 

I am not sure. I thought about sending the off to get cleaned and tested.

 

Do you have the vac line hooked up to the pressure regulator?
Have you checked your plugs?
Did you install that new filter you mentioned?
Are you running higher than stock boost?

 

yes
yes
not yet
no

 

Stock ECU or PFC?

 

It has a pfc. I plan on reinstalling the factory ecu tonight to see what all error codes it pulls. I know that it will pull codes for all of the emissions items I have removed, I want to check all codes to see if it is throwing any codes other than the items I have deleted.

 

That's a good idea. My guess is it's an AFR problem. The problem though is pinpointing the problem. It would help if you had a wideband to take some readings. You're O2 sensor is turned off on the PFC correct

Did you measure fuel pressure while revving it (no load)?

Is it possible to take measurements under load

The flip side is not enough air. Is your double throttle opening up?

Is the MAP sensor connected correctly (with a filter vs check valve)?

Any possible wiring/connection issues with any of the temperature sensors

 

yes the o2 sensor function is disabled

yes and it was fine

yes and it was fine

double throttle is removed

yes it is correct with the filter

all temp readings are correct

 

I removed the power fc and installed the factory computer. It threw an error code for the charge control solenoid. I removed it and tested it with a 9v battery and it seems to be functioning correctly. I cycled it a bunch on the battery and maybe it cleared the debris inside. I am going to buy a new one from mazda motorsport and see if fixes the problem.