DJ420a

Hey guys, Ive posted before about this prob and didn't get any help. I think I'm pretty much as far as I can go by myself.

1992 SC400

I have an ECU code 71 that I cannot get rid of. Ive totally taking of the EGR system out and thoroughly cleaned it, checked the EGR's diaphragm, cleaned the accumulator and its filter, all of this with no luck.

I have came to the conclusion that atleast on a 92 SC400, there is no EGR temp sensor.

I have even put a resistor in the VSV for the EGR with no luck.

Ive have tried to clear the code numerous times by either just pulling the EFI fuse or going as far pulling the fuse, disconnecting the neg. battery cable and totally unplugging the ECU over night. The code does clear, because I check it before I go to start the motor again and there are no codes but right when I go to turn the motor, the TRAC off and check engine lights come on.

I have some pictures of something that I think is missing from the engine bay, which may or may not have to do with my prob. I just see an empty plug next to a bracket that looks like it had something on it at some point and time.






Please, if anybody can shed some light on what else I can check, I would GREATLY appreciate it.

Thanks

DJ420a

Come on, does anybody atleast know what that part is thats missing in the pics?

Curry

iTrader: (1)

Have you tried leaving the sensor plugged in?

I deleted my EGR but left the sensor plugged in and tied it up in a corner. No issues at all.

DJ420a

What sensor you talkin about? The VSV or the EGR temp? There is no EGR Temp sensor in my 92 and as of today, I have tried 4 different (used) VSV solenoids.

Today I also removed the throttle body and thoroughly cleaned it, just incase theres a clogged vac line or something.

evileagle

You should replace the vac hoses with new ones. Most likely there is a crack/leak on one of the vac hoses thats causing the EGR valve not to open. This was just resolved by me 2 days ago as i needed to do the smog check here in cali. It passed easily when i replaced the lines, but 4 months earlier it failed bad.

DJ420a

I wish it was that easy bro. I changed ALL the vac lines like a week ago.

I dont understand, it runs a drives perfect now. Its just them damn two lights are on.

evileagle

are you sure the valve for the EGR is opening and fully functional? You will need a vacuum pump with a guage to verify that all the lines are correct and sealed.

jimgen1529

did you ever find the fix. I have the exact same problem. Went through everything. Even replaced a check valve on the way to the evap canister. I haven't replaced all of the hoses but they look fine.

DJ420a

Sorry man, I havent. I ended up taking out the bulb for inspection