LOSS OF BOOST... PLS HELP

[Jam-Dodge]

HI All

I've been running this ca18det engine for about 7mth now and no issues apart from the blowing exhaust manifold (gonna try and change those gaskets soon) just wanted some some help from all the experts on these cars. Right, When driving and i boost the car does boost but when i'm doing aroung 5-6k revs and downshift to a lower gear say 4th to 3rd the car LOOSES ALL THE BOOST its like its leaking from somewhere but i dont know where exactly. The cars o2 sens has been deleted and i can see it with the wires cut off and is running pretty rich, now i dont know if the exhaust manifold leak and the square gasket connecting the turbo to the manifold which is also leaking, would cause a problem. i've tried to like cover it up with exhaust paste to seal it but its just not gonna hold. in process of changing those awful gaskets soon

[mechanicalmoron]

That's not deleted, that's chopped off. You need an o2 sensor of some sort, and you need to fix that.

I would assume you're taking your foot off the gas, revs drop so it's harder to make boost, and the closed throttle pushes all the extra boost it's making during that time out the wastegate. I've never driven a turbo car, so this may not be it at all. But especially if there's a boost leak as well, it makes sense to me. You could try a flat shift, or shift with reasonable throttle at least and I bet it wouldn't happen.... but I alse wouldn't drive the car at all, other than to hobble it very carefully to the parts store, withouout an o2 sensor.

There shouldn't even be a plug for the o2, I expect. My replacement one just came with a crimp connector and some heatshrink. You realllllly need it.

[boost_boy]

HI All

I've been running this ca18det engine for about 7mth now and no issues apart from the blowing exhaust manifold (gonna try and change those gaskets soon) just wanted some some help from all the experts on these cars. Right, When driving and i boost the car does boost but when i'm doing aroung 5-6k revs and downshift to a lower gear say 4th to 3rd the car LOOSES ALL THE BOOST its like its leaking from somewhere but i dont know where exactly. The cars o2 sens has been deleted and i can see it with the wires cut off and is running pretty rich, now i dont know if the exhaust manifold leak and the square gasket connecting the turbo to the manifold which is also leaking, would cause a problem. i've tried to like cover it up with exhaust paste to seal it but its just not gonna hold. in process of changing those awful gaskets soon

You have the answer to your own issue in the fact that you are taking short-cuts on things are detrimental to your engine perorming at an optimal level. If you're leaking exhaust, then you're going to leak boost "POINT BLANK". No oxygen sensor? Great, now what do you think the computer's trying to do? Not only is your car running rich, you're leaking exhaust, your computer is limping you around town while you are trying to force the engine to go faster when it absolutely will not until you address the rigging and neglect of your engine. Correct the issues that you mentioned or you will soon be selling your blown CA18DET like so many that have come before you. You can't ICE SKATE up a steep hill my friend .

[Sideways s12]

Wow Is all I can say but Dee Pretty much sumed it up fix those issues and your car will run like it should barring anything you may not have mentioned....

[float_6969]

Yea, as the others have mentioned, that exhaust leak won't let the turbo spool properly, and you won't make boost. The missing O2 sensor is going to cause you all kinds of issues as well. Get the known issues fixed and make sure the ECU isn't giving you any codes. If you're still having issues then, post up about it.