99 Solara V6 EGR Issue
Looking for a little advice and understanding.
I've been fighting an issue for a few weeks and replaced several things to no avail.
I'm getting a P0402 "High Flow" code.
The real issue is that the car keeps surging at lower rpms. It almost stalls which triggers misfire codes. I found that even revving the engine up to about 1800 rpms I would still get a engine surge of about 100 rpms.
I was having a hard time figuring if the the non idling issue was causing the P0402 or vice versa.
I changed several parts including the EGR VSV, then the EGR, and finally the IACV.
All to no avail.
Today I pulled the vacuum line to the EGR and Presto the idle is better.
SO I started experimenting. I started over and with teh surging idle I disconnected the power to teh VSV. I thought that it would relieve the vacuum and fix the issue. Nope
I pulled the vacuum line from the VSV to the Vacuum Control Valve (BTW. What does this do? Regulate??) No change.
Pulled the line on the other side of the VCV and no change. But I did get good vacuum from the manifold.
Then I shut teh car off. I pulled the line between the VSV and teh EGR and go a release of vacuum.
I think I have figured out the problem, but not the why.
It seems that it is not releasing the vacuum between the VSV and the EGR so the EGR can never snap closed.
Please someone let me know if this is true. When you close the VSV the vacuum built up between it and the EGR should bleed off somewhere. Maybe thru the line to the air filter. Does this make sense?? I figure that the vacuum between the EGR and VSV has to go away somehow to let the EGR close at idle.
Any help in this area would be appreciated.
Bert
I've been fighting an issue for a few weeks and replaced several things to no avail.
I'm getting a P0402 "High Flow" code.
The real issue is that the car keeps surging at lower rpms. It almost stalls which triggers misfire codes. I found that even revving the engine up to about 1800 rpms I would still get a engine surge of about 100 rpms.
I was having a hard time figuring if the the non idling issue was causing the P0402 or vice versa.
I changed several parts including the EGR VSV, then the EGR, and finally the IACV.
All to no avail.
Today I pulled the vacuum line to the EGR and Presto the idle is better.
SO I started experimenting. I started over and with teh surging idle I disconnected the power to teh VSV. I thought that it would relieve the vacuum and fix the issue. Nope
I pulled the vacuum line from the VSV to the Vacuum Control Valve (BTW. What does this do? Regulate??) No change.
Pulled the line on the other side of the VCV and no change. But I did get good vacuum from the manifold.
Then I shut teh car off. I pulled the line between the VSV and teh EGR and go a release of vacuum.
I think I have figured out the problem, but not the why.
It seems that it is not releasing the vacuum between the VSV and the EGR so the EGR can never snap closed.
Please someone let me know if this is true. When you close the VSV the vacuum built up between it and the EGR should bleed off somewhere. Maybe thru the line to the air filter. Does this make sense?? I figure that the vacuum between the EGR and VSV has to go away somehow to let the EGR close at idle.
Any help in this area would be appreciated.
Bert
- fflint_18
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