No boost & erratic wideband reading

[1gDSM4g63]

The compression checks out and the boost leak and the leak down is all fine but the wideband readings are still erratic even with insane SAFC adjustment during idle, no boost, and the car dies down when throttling it at random time with in 2-3-4 gear.

Any other suggestion why this is happening?

 

[turboglenn]

Your question is far too vague.. we need details and fully structured sentences describing when and where the problems are. Are you saying it can't make boost, or the wideband is erratic when you're not in boost? Define erratic as well, what is it doing? If it's bouncing up and down while cruising it's probably the closed loop operation showing up on the sensor (never seen it before on a wideband though) what does the wideband do when you go full throttle? And what are the details and symptoms of what you're trying to say about the car dying when you give it gas?

 

[1gDSM4g63]

The wideband reading is jumping up a down during idle and while cruise and there is no boost.

 

[turboglenn]

Well, if you cant' make any boost, you need to check your turbo and do a boost leak test to find your problem. The wideband cycling up and down during idle and cruise could be closed loop as i said earlier. What does the wideband do if you go wide open and hold it?

 

[1gDSM4g63]

I'll have to test what the wideband reading are when throttle full open.

But if there is a boost leak, I haven't seen it this bad. When I say the readings on wideband is erratic during idle I mean it jumps back and for. I adjusted the SAFC to insane levels to get it closest to 14.7 but still jumps back and forth between 14-15 and occasionally too lean and this is with 950cc injectors, FPR, pump, the the whole setup.

 

[turboglenn]

Teh jumping is pretty normla behvior on a system running closed loop/ DOEs your wideband use the NTK or Bosch sensor? The ones that use teh NTK can sometimes pick up teh fluctuations from closed loop, where the bosch style units wont. And you are saying at wide open you can't build any boost? You either have to have a broken turbo or a blown off intercooler pipe for that to happen.

 

[1gDSM4g63]

I have a Bosch sensor. As for the turbo, I just install a new turbo and a new setup for the boost controller switching from Greddy electronic to a manual. The intercooler pipes are not blown off,
so unless the mbc is broken I can't thing of anything else as to the reason why there is no boost.

 

[turboglenn]

Even if the MBC was broken, you would at least still see the basic wastegate pressure in the system. If there's NO boost something is clearly wrong, and that's the FIRST thing to fix.

 

[8urv8]

Yeah, the wideband swinging back and fourth between 14.6-15.6 is normal. It's your wideband cycling and the ecu adding fuel as needed and taking fuel away as needed. It should do this both at idle and at cruise. As far as the no boost thing, I'd check the wastegate arm to ensure that it's hooked to the flapper arm. If it's not the flapper will just open up and you won't make any boost.

 

[8urv8]

Sorry. Double post.

 

[1gDSM4g63]

I ran the boost leak today and I assume there it a huge boost because I get any air pressure. The intercooler piping, mbc and wastegate vacuum tube are all connect.

I don't know if this is the problem. I found it under the battery rack with 1 of the 4 vacuum openings open.

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[1gDSM4g63]

Yeah, the wideband swinging back and fourth between 14.6-15.6 is normal. It's your wideband cycling and the ecu adding fuel as needed and taking fuel away as needed. It should do this both at idle and at cruise. As far as the no boost thing, I'd check the wastegate arm to ensure that it's hooked to the flapper arm. If it's not the flapper will just open up and you won't make any boost.

It swings back and forth between 14.6-15.6 but after a couple mins of idling swing back a forth 13-lean.

As far as the wastegate check, I have an external wastegate not an internal wastegate actuator . There is no arm.

 

[8urv8]

It swings back and forth between 14.6-15.6 but after a couple mins of idling swing back a forth 13-lean.

As far as the wastegate check, I have an external wastegate not an internal wastegate actuator . There is no arm.

Yeah, my fault. I didn't read your profile. It was an honest rookie mistake.