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I need your help guys! 740 Turbo Wagon Runs like Shiet!

1K views 8 replies 4 participants last post by  flygtig60 
#1 ·
I just picked up a 87 740 Turbo wagon today and it was running fine other then when you first started it the idle would go up to 2000 rpm a couple of time and then it would idle fine. I figured it was the idle stabalizer, so I took it off and cleaned it out...big mistake obviously! Now it is reving around 2000 & 3000 rpm at idle. I also noticed the all the wires 3 inches back from the plug were bare so I rapped them in electrical tape hoping this would solve the problem, but it didn't. I realy need to get this issue sorted because its become really anoying to drive.
 
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#2 ·
Re: I need your help guys! 740 Turbo Wagon Runs like Shiet! (flygtig60)

The first thing I would check is the throttle. when it is idling pinch off the hose that goes from the intake arm (to the throttle body) to the idle stabilizer motor. If your car dies when you pinch that off then you need to clean the throttle plate and recailibrate the throttle position sensor. Hope that helps http://********************/smile/emthup.gif
 
#4 ·
Re: I need your help guys! 740 Turbo Wagon Runs like Shiet! (towerymt)

I noticed this post is a bit old so I'm not sure this will help much now. I would second the notion that those wires you taped together are causing you trouble. I wouldn't be surprised to find out you need to replace the engine wiring harness. If you have bare wires there I'm sure it looks the same in other places.
 
#5 ·
Re: I need your help guys! 740 Turbo Wagon Runs like Shiet! (audinut!$)

It was only a small section of the harness (where there's a bent in it)
that two wires were bare. I've look threw the rest of the harness and it looks fine.
Why wouldn't taping them with electrical tape not work?
When I squeeze the rubber pipe going from the intake to the IAC it will idle normally, which would tell me that the IAC is pooched, but its not though.
Could the TPS being doing this? Is there any other way of testing the TPS?
 
#6 ·
Re: I need your help guys! 740 Turbo Wagon Runs like Shiet! (flygtig60)

Quote, originally posted by flygtig60 »
Could the TPS being doing this? Is there any other way of testing the TPS?

you can test it by just listening for a "click" when you start to open the throttle. it should click right when the throttle plate starts to open. If you take your throttle off you should be able to see daylight around the throttle plate as well, with it fully closed that is.
 
#8 ·
Re: I need your help guys! 740 Turbo Wagon Runs like Shiet! (flygtig60)

I also have an '87, but a 240 non-turbo. Same basic LH-jet 2.2 fuel system. I had high idle problems and I cleaned the IAC, but then it started idling high...sometimes. There's a plug that should be on the intake side, and it's just a little plastic piece with two wire connectors inside it. One is a test lead for the IAC, and if you ground it, the IAC will be removed from the equation. This is also used to set the base idle. If you ground the wrong one, you can damage the ECU, so make sure you know which wire is correct before you mess with this. I can check my manual for further instructions if you don't have anything to reference.

How did you rule out the IAC?
 
#9 ·
Re: I need your help guys! 740 Turbo Wagon Runs like Shiet! (towerymt)

I ruled out the IAC because if I squeeze the rubber line that leads into the IAC with plyers it will idle normal. This tells me that the IAC is not doing its what its supposed to, but even with a good IAC the problem still exists. I would really appreciate if you could send me some pics of the plug that you talking about and further instructions.
 
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