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Discussion Starter · #1 ·
Alright guys I need a little help on a project. I started the swap ages ago, and it went through several different stages, and as I'm sure you all know, sometimes life gets in the way and projects get placed on hold. I'll give you guys the run down, but it's late and I'm tired so I'm sure I'll miss some stuff. I'm swapping the 3b out of my 91 200 20vt into my 92 80q. The ECU I bought from a member here and has a stage 1 TAP chip. I've got the engine in and mostly wired up, enough so where I thought it should run well. It starts and idles, and if you rev it slowly with no load it seems to do well. but if you rev quickly is sometimes misses then backfires. I've only taken it for one spin around the block and it was god awful. Seems to have no boost at all until about 3500 when it shoots up to 23psi or so almost immediately and misses like crazy. There are a few things I'm concerned about, and would like some opinions.

First off, the altitude sensor. I do not have it, but I thought it only adds boost for higher altitudes, and I'm pretty sure it couldn't cause an issue like this, right?

Secondly I rebuilt the turbo myself. I've never done one before, but I'm very mechanically inclined, and went to school for automotive technology, so I'm pretty sure everything went well. However, I in no way think I'm too good to screw something up. Anyone think there a chance I messed something up in there? Should I maybe try running it with the wastegate open to eliminate it?

I'm running the stock 80q fuel pump. Have people found the stock pump adequate?

It looks like multi function coolant sensor was not hooked up to the ECU... can someone tell me exactly what this sensor does for the ECU? Could it effect timing/fueling?

I don't have the coding plugs wired up, so I can't run those yet.

I realize that's a lot. If anyone has some answers, advice, or questions have at it. Also if anyone has recently completed the swap and might be available for some more in depth questioning I'd be incredibly thankful. Thanks guys!
 

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The coolant temp sensor is -in the back of the cylinder head- for the ecu, MFTS does nothing with the ECU, its for the gauge.
I hope someone else will help with your boost problem.

Chris

ps: my bad, its for the 7a, sry
 

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Discussion Starter · #3 ·
I just found this.
"The 3B 20vt engine used the Multi-function Temperature Switch (MFTS) (aka "electronic thermal switch" in the 3B diagram below), located under the intake manifold on the auxillary coolant manifold, to send a coolant temperature signal to the 3B Engine Control Unit (ECU)to help control boost and fuel. (See link to SJM Autotechnik below)(Replacement MFTS PN is 034919369C, plastic connector, if it breaks, is 893971974)"
 

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Discussion Starter · #7 ·
No worries thanks for the input man.

Something tells me it's not that though... this thing runs like complete dogshit and I get the feeling that would wouldn't render the car completely undriveable...
 
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