sideways_fc

iTrader: (1)

Okay guy I have a 93 auto to manual swap. My problem is when the car is cold the idle hunts up and down. When warm idle is steady at 1000rpm but looses a lot of power and boost please help this has been a 3 year project

DDagman

iTrader: (3)

We need more info about the car. Mods, etc. at what RPMs does it loose boost, how much of a boost drop. How many miles on the motor? What are the compressions on the rotors?

sideways_fc

iTrader: (1)

The car has intake straight pipe exhaust simplified seq vac block off plates chipped ecu

Motor has 100 psi front and 90 rear about 40xxx miles

I've tried pulling codes it gives me
23 fuel termosensor
28 egr
30 split air bypass
38 accelerated warmup system/air supply
39 relief 2


The car boost about 10. Psi when cold. When normal operating temp doesn't boost at all. When it warms up idle is smooth. When cold idle hunts

I've tried differnt ecu
Cleaning spark plugs
Compression check

I believe it's wiring or a sensor any help would be great thanks!

Mahjik

iTrader: (1)

Likely your problem is with error code 23 - fuel thermosensor. That will likely put the car into limp mode which sounds like what you are experiencing.

sideways_fc

iTrader: (1)

I'll look into that I didn't know that code will throw the car into limp mode thank you

sideways_fc

iTrader: (1)

Update got the wiring correct now. No code23 cars idle still hunts till fully warmed up. But the main issue is the car won't boost once fully warmed up please help anyone!!!!

Mahjik

iTrader: (1)

Can you provide more information on the car? Was it running fine, then an auto to manual swap was done and now the problem is there? Was the engine swapped out and then the problem started?

sideways_fc

iTrader: (1)

Okay I bought the car as a rolling shell. Motor was separate did the wire harness conversion (auto to manual) . Never really did run right tried pretty much everything. Any help would be great

Mahjik

iTrader: (1)

Start with the CAS:

* Make sure you have proper continuity between the sensors and the ECU
* Make sure you have the connectors on the correct sensors
* Make sure you have the proper clearance between the sensors and the trigger wheel
* Make sure the trigger wheel isn't bent

sideways_fc

iTrader: (1)

Ill double check but if the cas was bent or wired wrong. why would it work cold and not hot wouldnt it jus be messed up from start up. just think aloud

Mahjik

iTrader: (1)

Typically with CAS issues, the car will start and idle but will stumble and fall when there is load (acceleration). Your symptoms currently sound like this unless you are having new/different issues. It's a misconception that any CAS issue results in the car not running.

First rule of troubleshooting, eliminate what is NOT the problem.

Mahjik

iTrader: (1)

Actually, I do believe you had an older thread:

https://www.rx7club.com/3rd-generati...-997147/page2/

sideways_fc

iTrader: (1)

Yes i did have another thread before never got the running right ever since ever. ill double check those things its just weird that only after its warm and boosts it does this. also can i check my timming and trouble shoot the cas?

Mahjik

iTrader: (1)

If you look in that older thread, you mention there was some damage to the trigger wheel.

If you have a PFC, you can use that to check the voltages being received by the ECU from the crank angle sensors. Other than that, just follow the FSM for checking the CAS's and the trigger wheel (and their tolerances). The FSM references the CAS as CPS (Crank Position Sensor). The sensor clearance is referenced on F-166:

Measure the crankshaft position sensor to crankshaft
position sensor plate clearance by using feeler gauge.
Clearance: 1 .O-2.0 mm (0.039-0.078 in)


The other things to check if everything is ok with the CAS/CPS and trigger wheel would be:

* TPS
* Fuel pressure/regulator

However, eliminate one thing at a time.

sideways_fc

iTrader: (1)

Thank you for the quick reply's I guess I'll try and decide if I need to buy a power fc or keep messing with it...

SWAT81

iTrader: (14)

aside from the hand full of error codes, your compression numbers are quite low especially on your rear housing, if you motor has not been ported I would say its almost on it's way out for a rebuild soon.

sideways_fc

iTrader: (1)

I know I am gonna try the mavel mystery oil trick I think the motors been sitting so long that's why.

Update I just ordered a power fc to shine some insight but I tried switching Ecuador between stock chipped and Jdm. The funny thing is the Jdm doesn't throw any codes (but runs like ****).. The USA ecu throws 23 28 30 38 39 . The chipped has all the same except 23 fuel termosensor any tip would be great thanks

sideways_fc

iTrader: (1)

Update I just got my power fc. Still no boost idle hunts please help someone!!!!

Mahjik

iTrader: (1)

I'm not surprised the PFC didn't magically fix your problem. That was not really the intent. You can use the Commander to troubleshoot a little easier (i.e. you should be able to see voltage ranges for the sensors and validate they are within tolerance).

sideways_fc

iTrader: (1)

Well everything seems okay nothing highlighted. could it be my wastegate is stuck open?

sideways_fc

iTrader: (1)

Bump please help someone tried wastegate not it

ondabirdhouse

iTrader: (26)

What can you tell us about the simplified solenoids controlling boost?

Also. Did you modify the auto engine harness or did you swap it out with a manual harness.

sideways_fc

iTrader: (1)

Still using stock solenoids. I did the auto to manual. Harness conversion by repining the clip any help would be awesome thanks

Mahjik

iTrader: (1)

Have your gone through the "Control System" section "F" in the FSM?