How to Quickly Test Your Boost Bypass Actuator

In this video, I demonstrate how to quickly test your boost bypass actuator. This method doesn't require any special tools or technique. You are simply checking to see that both chambers of the actuator are sealed and not ruptured. These can be a little tricky to source nowadays due to there being many different versions with ports clocked in different directions so if you need a replacement, make sure you get the right one if you're going for an OEM replacement. That said, they all work about the same and I have interchanged them before on my truck with different models in a pinch. Vehicles that will have this bypass actuator or similar include but are not limited to: SVT Lightning, SVT Cobra, Supercharged 3800 cars such as Pontiac Grand Prix GTP, and Buick Regal GS, Nissan Xterra and Frontier, GT500, and LSA applications (among others). A symptom of this failure would be the car not making as much boost as normal and blower over temp.
#605BOLT #eaton #svt

[@tableseven8133]

In looking this up today to be sure I was on the right path, I found several post on the web where people are at a loss about this parts function and what troubles it makes when not working well. That is why I put another longer post here, and may post it on FB as well.

[@tableseven8133]

Ok this was very helpful for me. Through a bunch of garage visits of my Buick Riviera 97 (99) and also trying several things they suggested as well as putting fuel/valve cleaner in the fuel. Now before I take you all down those trails, this part, supercharger bypass actuator, here is what I found that replacing it fixed this problems for me. And I just checked it today after seeing this video and it is leaking from the top air part, slow but enough that it did not hold the pushed in pressure but the bottom air part was fine. Not knowing how to safely test the unit, and blowing into it on both sides seamed fine, but I could barely make it move by my air alone, but todays test proved it. Rabbit trail, recent past history: I put it on my car last week, and drove around town over the weekend and tested the power after three very short trips around town. I did not want to be stuck with it at a awkward place nor run over anyone, when hitting the gas harder they the old very slow man way I had to drive it. Well I was pleased with it and drove it to work and back the next two days and it was fine. (45 minute trip each way.) I was still leery of it since this problem for me was a hit or miss every day, or every minute. Rabbit trail earlier history: I had the car in for state inspection and told my mechanic of the problem and said it was like the older cars that had no spark advance, and in my case the car at times died or almost died when pulling out into the high speed highway traffic. One time I had to pull off since it was not moving very happy and back fired a few times, and from that point on I drove it very little or only drove on the lower speed road and did not push it at all driving like a old old man way. So when I picked up my car they told me it was better and that the MAF sensor came up as the problem, but they found that the fuel line filter when they went to remove it the line broke at that spot and they had to repair that as well but found a lot of sludge in the fuel line thinking that was also my problem of lack of power. I picked up the car that evening and went on a short drive and it was still about to die with to much acceleration, so I pulled over and disconnected the MASF sensor, thinking that was the problem, and it did run better but still was not well. So I got another MAF sensor, a better brand one from the auto parts store, the next day. It one and off and it was the holiday weekend, so I did not put it on till Wednesday morning before going to work. I drive literally about 2 minutes and the car engine flutters badly and dies after I made a left at a traffic light. I pulled over and disconnected the MAF and drove a little and then and drove back to the garage quite upset. I decided to look again at things under the hood and found the problem part I often had with this car since I bought it. One the vacuum lines there is a line that has a sharp 360 degree bend and another that has a 90- 100 degree bend. The second one is just rubber and it will crack and leak giving me a check engine light or a engine flutter at times but it never would have the engine die on me. About every 6 to 9 months I have to replace it or cut the ends off to have it seal again. So thinking this could be the problem I did not return the car back to the mechanic. I trimmed it off and put it back on and drove my other car to work. I came home a looked under the hood again looking for any vacuum leaks, and finally found what I thought was the problem, but I also found that the new MAF sensor made the car much worse then the one that was in it before, or the one before that. I had them both in the car, so I figured I had a defective MAF sensor as well, I need to be on the ball about that since this one required a core of the old one to get my $70.00 back, but I figured it was defective and in the mean time I found what I thought was a broken connection on this supercharger bypass actuator, but had no idea what it was called. Well at the auto parts store they did not have another of the same brand of the MAF, and despite me telling them it made the car worse and it was only in the car for a few minutes they did not allow me to get a refund for it since it was used now, I was even willing to give them one of the other MAF sensors and I still did as the core refund, but had to buy another MAF and applied the credit to it. Ironically, and I have to thank God for this, that top hose connection on the supercharger bypass actuator was not broken, it was just a sliver of the hose, another tight bend, hanging weird on the end making it look like it was cracked and I did not want to pull on it at the time till I bought a replacement. The replacement top connection was not at tight and required me to get a longer hose for it but the problem is now resolved, I'm very sure. Especially after doing the test, as this video showed, and found the top one is leaking badly. Rabbit trail very old history: I knew when I bought this car, it was almost a give away to me, I was in for some learning curves. This was the most recent one. I have a 1991 Pontiac Sunbird V-6 automatic and found with them; (I had one or more of these since 1992 (1992 L4 stick, 1993 V-6 stick, 1990 old L4 automatic.)) Especially the V-6 that the ignition coil pack with the electronic ignition is mounted to close to the hot engine, well mounted right on the engine side, and over the warmer day to summer days the car would have running problems, I moved that item off the engine and over to the fender and have not had to replace the ignition module since. Making them the most dependable cars I have ever had. The 1993 I sold it 2 years ago having it over 300,000 miles and still working well but the under body/uni-frame rust was just to much.

[@605BOLT]

Dang this is the longest comment I've ever had on this channel haha. Glad to know you got her fixed it sounds like. Thanks for posting your comment for others to see.

[@tableseven8133]

@@605BOLT Well the story is not over yet. Car still has acceleration trouble.

[@605BOLT]

@@tableseven8133 dang it man. I thought you were on to something.

[@tableseven8133]

@@605BOLT The part you showed did have a problem of a partial leak on the top side. I found a open elbow connector on the part that I think goes to the evap. tank, or close to that part, but did not find what goes into that other end. But it goes to my suspicion that when the spark plugs were changed at the garage they knocked something out or off. now on the other side of that same round thing another elbow that I can sea easily often will crack and leak, but I never saw this other connection until this week and having a elbow on it tells me it is missing plastic tube, otherwise there is no. purpose for the rubber elbow part. I could not feel anything near there that was not connected and it is on the underside and in a tight spot. I fine there is not any great visuals on this engine of the vac lines and the supercharger connections, and the drawing I found some are very different, or have some extra part or mine is missing a part. Who knows. All I know it worked great until I had it blow out a spark plug about a year ago now and did not know that was the problem and my mechanic replaced them all then. Then I had air shock trouble and did not drive the car much till that was fixed at a Buick dealer. Then some times I had full power and no problems and the next it would die or almost die as I am speeding up to get on the highway, with it. and then the dying problem became worse and worse. MAF sensor helped some but did not fix it...

[@605BOLT]

Ugh man that sucks. Keep after it. You'll get it figured out.

[@claudiodueviti]

tyhanx, was looking for this info !!

[@605BOLT]

Happy to help!!

[@clydewarman1576]

Very helpful

[@605BOLT]

🙏 my pleasure.

[@Corvette_q8]

My supercharge c7 z06 boost not stable with full throttle also it is from this part ?

[@605BOLT]

@@Corvette_q8 could be that or belt slip.

[@405SVT]

I bought a boost bypass from zz performance and the shaft was shorter then my oem and I couldn't get it to work, have you heard of anyone else trying those?

[@605BOLT]

I have. I think they basically operate all the same except the end of the rod could be different. I got mine from Jon Bond performance in Iowa. Do me a solid and mention you saw this video if you give them a call. 🙏 They're spendy little buggers though. Zzp would probably have what you need too. Maybe just an easy mixup like one from an M90 or something else. I think the gxp Pontiacs and bonnevilles have the same style though so hard saying what happened exactly.

[@Daniel.r-o8x]

Thanks

[@605BOLT]

🙏Merry Christmas.

[@beavisdoubleo76]

What were your symptoms that made you realize it was bad?

[@605BOLT]

None. I was just doing checks when installing the new blower. I think I broke it by blowing into one of the ports with some compressed air to test function. It doesn't take much to break them. You should be able to get the bypass to cycle by quickly and sharply revving the engine. Blip the throttle and it should flip shut for just a moment.

[@EEI605]

Easy test!

[@605BOLT]

Yes it was!

[@stevegee4166]

A

[@605BOLT]

@@stevegee4166 👍👍