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This XT is killing me!


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So I really have checked everything but I still have issues. The XT starts now, but... It gets to 400 rpm and then it dies. It gives off a sweet smell, like it's too rich. If it's flooding then that would explain it but, I don't know what to do to lean it out. The idle adj. screw is right in the middle, not loose, not tight.

 

EA82T (minus the turbo) (i know it won't be as nice)

1987 XT MPFI

all stock except the engine

Had to swap cuz the original blew

(Couldn't get another N/A at the time)

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This is really funny - i have a 1987.5 XT Turbo that i castrated to non-turbo as well. Got a real nice JDM motor "low mileage" complete with blown head gaskets (thanks alot!?). Started 4 years ago and still haven't got it running right yet.

 

What did you get from the engine codes - any current codes? any from read only? any from diagnostic test? All of that only takes a couple minutes to figure out.

 

Are the timing belts and distributor installed correctly - it's very easy to do those wrong even though it looks right. The timing belts are the opposite of the new stuff so folks get those wrong often.

 

Have you check for spark?

 

Vacuum leaks - try some starter spray all around the intake while cranking the engine.

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So wait, you are running a Turbo engine without the turbo in the car?

 

That could be a problem right there if you did not swap out the turbo pistons for NA.

 

You're compression is down to 7.7 from 9.5. The ECU may not have the right fuel map for running such low compression.

 

 

 

But, assuming it could run but just isn't, I'd start checking for any Vacuum leaks, cracks in the intake tube, and of course double check that the screw is in the rotor.

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This is really funny - i have a 1987.5 XT Turbo that i castrated to non-turbo as well.

 

Funny, I just finished installing an NA block with my old turbo heads(after welding the exhaust cracks) and a Spider intake.

 

I love the MPFI Spider Non-Turbo in my 89 wagon. it is Sweet. Hopefully the OP of this thread will be able to experience the same joy eventually

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  • 1 month later...

So my final conclusion is that I overlooked the most important thing. The ECU. The ECU i'm trying to run is non turbo. It's a turbo motor. The comp ratio is different between N/A and Turbo. I'm dumb. So I need to beg someone to ship me a EA82T ECU.

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I think the ECU is the problem, but maybe not in the way you think it is. XT's in particular are really goofy around 1987, it was a transition year. It's a horrible year to go swapping engines.

 

XT's changed a lot from 86-87 and from 87-88. Your problem isn't that it's a non-turbo ECU, but probably that it's the wrong ECU entirely.

 

You can't just throw any EA82 ECU in there and call it a day.

 

You'll actually want to verify your build date and make sure you get an ECU that matches your XT wiring.

 

In other words - whatever your build date is you'll want an ECU to match. And the non-turbo ECU should work, but you can try a turbo ECU if you like.

 

Was this XT originally turbo? Are there lights in the rear bumper or no? I think the lights should be above the bumper and yours is a later model given the details you've shared.

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I believe it is an early 87 XT because it has the Reverse lights ON the bumper. The car was originally N/A and I put a turbo engine in it. The reason I'm thinking the way I am is because the N/A engine has a comp ratio of 9:1 and the turbo is 7.5:1. That being said, the stroke of the piston is less and therefore should require less gas. The N/A ECU is providing too much fuel and the engine is choking. It will start only if I have the Throttle at 100% and it gives off lots of exhaust which is the fuel not being burned. A turbo ECU should give the engine the appropriate amount of fuel.

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it'll be best to start out diagnosing this rather than throw parts at it, there's a chance (a good one) that it's not the issue you think it is.

 

you are right - reverse lights in the bumper means the earlier 87 - or up to 12/86 build date.

 

do you have the original ECU in there, or something else?

 

When you swapped in the EA82T motor - what intake manifold wiring did you use?

 

you need to tell us exactly what is in the car and we'll go from there.

 

is the wiring and ECU stock non-turbo except the Engine or did you swap other stuff?

 

and exatly what EA82T did you put in there, there's a few different variations.

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"do you have the original ECU in there, or something else?"

It is the original ECU

 

"When you swapped in the EA82T motor - what intake manifold wiring did you use?"

I used the turbo intake. I used the N/A fuel rail and wiring. The intake is the same between the two, minus the extra vacuum lines and coolant line to the turbo.

 

is the wiring and ECU stock non-turbo except the Engine or did you swap other stuff?

I only swapped the engine.

 

"and exatly what EA82T did you put in there, there's a few different variations."

It was a '82T out of a loyale, I don't know which version.

 

The version shouldn't matter. It's an engine, the mechanics is all the same, it's an engine. The cams are in the right place and i put the disty in the right way, everything. I have the mechanics part down. It's a fuel to air ratio issue. My original thought was it's not getting enough air, but if you reverse the equation you can assume its getting too much fuel. Considering the difference in compression ratios between the two engine models it makes sense. the ECU is telling the injectors to stay open for longer because it thinks the comp ratio is higher. If I have a Turbo ecu it will assume the correct ratio and give the engine less.

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I was mainly wondering what wiring harness you used, hence my question about engines/intake manifold - i realize an engine by itself is just a big pump.

 

I know one other person that has done this and ran the car with everything stock, except with turbo pistons and the car ran fine....lower power obviously but it ran.

 

The O2 sensor, MAF, and TPS (?) also play a role in air to fuel ratio.

 

The ECU is easy to replace, so that's awesome, you'll just need to make sure it's for a 12/86 or earlier MPFI vehicle, all EA82T ECU's are not interchangeable.

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