Ka24det bottom mount wastegate mounting?

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lowwy
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Hi, I got this car in limp mode and have slowly been fixing it.

91 240sx with a ka24det

The wastegate wasnt even mounted and was zip tied hanging. I don't understand how it is supposed to mount to the turbo. I googled an image of the turbo in it (WGT2860) and it seems that the wastegate mounts on the back but I have no clue how to make this work?

Also, another problem i'm having is the car will not start on its own when it's cold. I can get it started with starter fluid and it will idle and run, but sputters hard at around 3500-4k rpm. I know I have a bad boost leak but it seems like there may be a fuel issue but I'm not sure. I know im getting good fuel pressure to the rail but not sure beyond that.

Help please, any suggestions on the wastegate or what to check next for the starting problem?

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AZhitman
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Welcome aboard!

Wow... where to start...

What engine management?
Have you tested for power to injectors? Are they spraying?
We're gonna need to know a LOT more before we can even start... Stop spraying starter fluid in it - if the wastegate isn't even attached, and it's got a ton of boost leak, it's not gonna run right anyway.

lowwy
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Thanks! I'm new so i'm learning as I go.

I asked the previous owner about engine management and he said it has a Jim wolf tech chip in the ecu.
I have not tested the injectors yet. Looking to buy a voltemeter here in the next few days. How Do I check if they are spraying? Do i pull one injector out at a time or the entire rail off?

And I just learned the wastegate isnt attached yesterday, havent started it since.

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PapaSmurf2k3
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Its easiest to pull the whole rail to check for injectors spraying.
In fact, you need to so that the injector is still installed in the rail, and gets fuel pressure.

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PapaSmurf2k3
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I just fixed your image tags in your first post. Try to make sure there's a ".jpg" at the end of the link (between the image tags), or it wont work.
The wastegate being messed up doesn't have anything to do with your starting issue. With a wastegate being wide open, you just wont build boost. Typically they bolt to the compressor housing but you can rig it up however you want. I've welded extra bracketry to mine to get it to be able to bolt in to a different location while maintaining a proper angle for the rod to the wastegate.
This is a fairly common problem when you clock the compressor housing in relation to the turbine housing (for packaging reasons).

On to the starting issue - you mentioned you have to spray starting fluid to get it to start. This typically means that its either not getting enough fuel as normal, or you're getting too much air, like a vacuum leak. I'd check everywhere for cracked or broken hoses, as well as the injector test mentioned above.
Do you know what size injectors are in the vehicle vs what the ECU is programmed for? Often times a chipped ECU doesn't map the injectors very well (usually because the injectors aren't what they say they are). Once you rule out all the other stuff mentioned above, you can remedy this by installing an adjustable fuel pressure regulator, and increasing the pressure.

lowwy
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I think I found the starting and sputtering issue. It was a bad MAF.

Still need to figure out what to do with the wastegate, it actually builds 10-12lbs of boost and seems to hold it with the wastegate just sitting there not bolted down.

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PapaSmurf2k3
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That's freaky... does it wait until like 5,000 RPM to do so?

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WDRacing
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The wastegate actuator is probably "stuck" closed in the position it's mounted in. So it's building boost but it won't be regulated at all. I'd disconnect it entirely until you get this running at 100%. Disconnecting it will just have the wastegate open all the time which is your best bet with unknown issues on the tuning side.

Fix all the leaks. That's definitely the first thing you should do. Get it to start and run at idle and then check your ignition timing.

Once the timing is set to stock and the idle is good to go you'll need to have the actuator part of the wastegate hard mounted to the turbo in some manner. It's easier than you think if you don't mind some diy fabrication. I've seen angle iron used before, the kind people use for a garage door opener.

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PapaSmurf2k3
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Typically a wastegate that isn't bolted down is open more times than not. Exhaust gas presses against the wastegate and wants to open it, not keep it shut.
If the wastegate was bolted down but had no vacuum/manifold pressure going to it, then yeah, it would be shut all the time.

lowwy
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Well I was wrong about the MAF being the starting issue, tried to start it after sitting all night and it wouldnt go. However the sputtering has completely stopped.

And no it beings to build boost around 3500 I believe. Stops right around 11 psi.

It starts fine when its warm (i have to give it gas), but when its cold, nothing. Sometimes ill get a little sputter to 300rpm but then it just cranks forever.

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PapaSmurf2k3 wrote:Typically a wastegate that isn't bolted down is open more times than not.
Totally. I'm just picturing the wastegate actuator "wedged" in place. That's the only way I can explain it still building boost, why I said disconnect it entirely until everything is sorted.

When cold the engine loves to run rich. Lots of cars have an additional injector that sprays extra fuel just under cold start conditions. If you have a leak in your intercooler pipe you're going to be running leaner than the car likes, especially at startup. I'd take apart the intercooler couplings at every joint and check them for cracks and reattach them. That way you know for sure things are sealed correctly.

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PapaSmurf2k3
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Where is the MAF on your system? Do you run it on the sucking side of the turbo, or do you run a "blow-through" setup, where the MAF is actually in the charge piping?

The closer it is to the throttle, the less stuff can go wrong. You could even disconnect your tubing all together and put a factory style intake on there just for now for diagnosing starting issues.
Usually decoupled couplers don't cause a starting issue, they just cause a bad running issue. I'm still saying you're not getting enough fuel for startup though. Can you try turning the key from off to On multiple times before cranking and see if that helps?

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I've seen disconnected charge pipes prevent starting many times. Granted, they were totally popped off.

I like the idea of converting it back to a stockish style intake though. Remove as many variables as possible.

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PapaSmurf2k3
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Yeah I guess if the pipe were disconnected, it would still get that initial fire, but would die immediately once it tried to look for MAF signal to determine how much fuel it needed.


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