Help! No boost and weird boost gauge readings


Fresh Recruit
Hi everyone I need help. My car suddenly lost top-end power. The cluster boost gauge seems like it isn't building any boost and sometimes it turns the digital lights in a weird way.
But when I disconnect the map sensor the digital lights seems to be ok
I already change exhaust and intake gaskets, intercooler hose, wastegate actuator and spark plugs just in case but the problems still been the same do you think that that map sensor could be causing this? It's a 3E-TE with a ct9 turbo everything else it's completely stock.


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Hi there and welcome to the site.

Yes if the MAP sensor is reading incorrectly it'll cause the symptoms you are seeing but I'd be inclined to plumb in a mechanical boost gauge (even temporarily) to make sure there isn't an underlying issue. If possible donor a good sensor in and cast your eye other the vacuum piping in case there's a cut/rub somewhere.

Great to see a different setup, we're way too used to 4EFTE!
Jay, at first i was wondering if the car's ecu was acting like its hitting boost cut? but then the lights issue is strange
can you do a diagnostic on your car?
did you install anything recently? can always check the connections and for wiring/electrical issues
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What car is this? I love the boost gauge!
If you say its loosing power then do not drive it till you fix it.
It could be going lean and this will destroy your engine in no time.
the map sensor is a good start but also make sure your wiring is good.


Fresh Recruit
Hi everyone and thanks for answering. Updating the problem I already test it with another map sensor and I still having the same issue so I change all the vacuum lines but nothing changed. The only thing I installed was a blitz downpipe but it was after having the boost issue so as gorgan said I made the ecu diagnosis and the only check light code I got was the 51 that I thought it was from the air con (the last owner removed the air conditioner) so I didn't espect that was a problem but some friends told me that that's the same code as TPS sensor is that true? That could be causing all this problem? I'll try testing the TPS and I'll change the BOV cause I can hear a whistle frome there. This is a tercel GP turbo '86 with a 3e-te
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I am not sure about the code 51.
Maybe change the TPS, and make sure you are doing it correctly using a multimeter.
Also I do not think that your TPS is a potentiometer type. It is only there to say "Idle mode"
I could be wrong though.
Other things to test is actual fuel pressure while driving and in boost and the other you need to test is use a mechanical boost gauge :)

On an off topic note, please add your car by Members Showcase. Love your car! Would like to see more of it!


Fresh Recruit
Well thanks to everyone for the help. Finally I found the main problem. After changing 2 damaged BOV and coolant temperature sensor I noticed that I fixed the boost leak and have more high end power but couldn't get full boost so I shim the wastegate actuator. Now I have full boost (0.9 bar) and everything it's perfect. Now that I finished everything I'll add more photos of my car at the members showcase. Thanks for all the help