1GR TRD S/C Bypass Actuator Part #?

Has anyone replaced the bypass actuator on their 1GR TRD S/C? I get periodic symptoms of a bad actuator, especially when temps drop into the 20s. When I move the actuator by hand a few times it seems to loosen up and work fine for a while. Symptoms are choking with heavy throttle/WOT, occasionally running lean and rough at idle.

Questions...

I think the part number is VA783A. It is listed as the actuator for the TRD S/C on the FJ. Strangely it is not shown on the Tacoma section of the page. Can anyone confirm?
http://jonbondperformance.com/index.php?main_page=product_info&products_id=86

For anyone that has replaced it, were you able to do it with the S/C mounted or did you have to take it off the motor?

Thanks!

 

I wish I could be of help man. I know nothing about the replacement part number for our bypasses.

 

Dude its a lost cause. You should just remove it. I will dispose of it for you if you like

 

Ah! Jon Bond Performance updated their site to include the listed bypass actuator as compatible with 05-15 Tacomas. Looks like I got my answer. And it can be had a lot cheaper than $110 with a search. I have to take the S/C off for maintenance soon anyways so I think I'll just do it all at the same time and save myself the headache of working in the 2" space between the back of the S/C and the firewall.

 

Strange cause i would think it can perform not well on vacuum but not Under pressure at WOT. My understanding is that the bypass is normaly closed and it's vacuum that open it at idle. Do you have a boost gauge?

But i'm maybe wrong, you know.

 

I'm pretty sure it is supposed to be open at vaccuum and then seal when boost is being introduced so that it can build up pressure, not the other way around as you guys mention.

 

^ correct.

The symptoms I'm having are indicative of a bypass actuator that sticks and does not fully open/close. Not fully closed + throttle = choking, don't get full boost, rich, bad mileage. Opposite at idle/vacuum when the S/C should not be feeding. Haven't thrown any lean codes yet, but my O2 sensor readout maxes at 20 AFR and I get that occasionally when its acting up.

 

I definitely notice a choke/hesitation here and there with quick throttle.... Curious what was causing this? I thought maybe the Ucon didn't like the cold weather but maybe its this bypass valve

 

I would replace it then. It sounds like it is bad.

 

Please give an update once you get the new bypass actuator. Curious if you can tell a difference between the two with both uninstalled?

 

Easiest way to test is to remove the vacuum hose which feeds it, and plug the hose. Then test drive. Realize that the valve will be continuously closed during the test drive.

 

Just wanted to update everyone! Replacement bypass actuator did the trick. Also changed out nose drive oil, replaced nose drive coupler, regreased the impeller bearings, replaced spark plugs, and cleaned up the insides. Power and mileage are back, no stuttering or hesitation.

Also, John Bond performance sells a replacement bypass actuator but the part number is NOT correct. They sell VA783A as fitting the 1GR TRD S/C. Confirmed that VA783 (no Alpha) is correct. Part costs about $70 shipped if you search.

And the iridium plugs that came with the kit were on for about 85K. They were totally cooked. If I get there, the next set will be changed at +60K (I'm at 100K now).

Unable to upload photos from phone right now.

 

Bam! How did you test it, or did you just replace it?

 

I had fully intended to replace it anyway when i started this job but I figured it was a likely culprit since it would happen more often when cold and working the actuator by hand would fix it for a bit.

Once I had the SC body off the motor I was able to easily play w the actuator. If I snapped it full open and released it the diaphragm would occasionally fold over and stick in a partly open position.

 

Good find.

 

Pics! Insides were gross even though I'm running a catch can. Plugs on two cylinders were shot with 85K on them.

 

Holy fawk! The electrodes are gone! Was the foam seal around the intercooler still there or gone as well?

 

I bet more people have a problem with this than they know. As I alone have helped three. I am betting that Rocklobster is another. That many more are as well, but due to the nature of the whole change, they aren't aware of it.

 

They are! I'll never know if they were gone from miles or if they were roasted when the AFR started to get screwy, but I'll definitely change them 60K from now instead of 85K.

The foam seal around the intercooler was in good shape but the glue that holds it to the intercooler released when I sprayed the whole deal with MAF sensor cleaner to remove the gunk. After the cleaner dried off the glue was sticky again and held the foam seal just fine

 

Did you take pics of the intercooler also? I'd love to see some, no one has posted any that I know of. I have a 2014 V6, so should be just the same as yours I think.

Didn't know about the foam seal, be nice to know more.