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Old 01-05-2012, 02:38 AM   #1
laturnus
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Default 7mge swapped 4runner help

i have a 1987 4runner with a 7mge swap out of a 89 supra. I have had several problems with the wiring in the truck because i obtained it from a close friend who in turn bought it from someone else who had no idea how to do automotive wiring. I finally got it running today with the E1 and T terminals jumped to do the timing. It was running perfect at 15*. I turned the truck off with the diagnostic jumper wire still in, when i tried to start the truck again it would not run. I pulled the diagnostic wire out and it started to run very rough like it wasn't timed again. While it was running poorly, i jumped the terminals, it revved very high then died suddenly. It starts with no jumper in and runs for about 5-10 seconds at what sounds like 400 rpm, but with the diagnostic jumper in it will not run. Someone please help.

thanks,
Mark
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Old 01-05-2012, 03:44 AM   #2
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First off, you can not set the timing is ANY codes are stored in the ECU. Make sure it's clear first.

Second, base timing is 10?BTDC, not 15?.

Third, with the diagnostic jumper in place the ECU runs by a very strict base timing map; Out of diagnostic mode many factors cause shifts in the timing and timing is at no point static (in other words it's constantly changing).

Fourth, turn the car OFF before removing/inserting the diagnostic jumper. Trying to switch back and forth while the ECU is powered may yield unpredictable results or even cause damage to the ECU.

Fifth, the vehicle needs to be up to normal operating temperature before setting the ignition advance.

Sixth, have you verified that the mechanical timing is correct?

Seventh..... There's nothing I hate more than fixing someone else's poor swap... Welcome to Hell.
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Old 01-05-2012, 04:12 AM   #3
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Quote:
Originally Posted by cre View Post
First off, you can not set the timing is ANY codes are stored in the ECU. Make sure it's clear first.

Second, base timing is 10?BTDC, not 15?.

Third, with the diagnostic jumper in place the ECU runs by a very strict base timing map; Out of diagnostic mode many factors cause shifts in the timing and timing is at no point static (in other words it's constantly changing).

Fourth, turn the car OFF before removing/inserting the diagnostic jumper. Trying to switch back and forth while the ECU is powered may yield unpredictable results or even cause damage to the ECU.

Fifth, the vehicle needs to be up to normal operating temperature before setting the ignition advance.

Sixth, have you verified that the mechanical timing is correct?

Seventh..... There's nothing I hate more than fixing someone else's poor swap... Welcome to Hell.
thank you for the help. greatly appreciated. yes the mechanical timing is in order. so in other words, i need to clear the ecu codes, put in diagnostic jumper, set mechanical timing, let it run until warm and then set timing?
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Old 01-05-2012, 04:58 AM   #4
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Yes, well, if there are codes present you need to fix whatever is causing them first, but yeah you've got the jist of it. There are some issues for which a code may not show up which will cause a drastic change in timing to kind of hide the symptoms, such as a bad AFM or ECU coolant temp sensor... Might be worth testing them to make sure they're all up to the specs listed in the TSRM.
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Old 01-08-2012, 01:29 AM   #5
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Quote:
Originally Posted by cre View Post
Yes, well, if there are codes present you need to fix whatever is causing them first, but yeah you've got the jist of it. There are some issues for which a code may not show up which will cause a drastic change in timing to kind of hide the symptoms, such as a bad AFM or ECU coolant temp sensor... Might be worth testing them to make sure they're all up to the specs listed in the TSRM.
i got the truck running well. only problem i am having now is idle.
the rpm will go up and drop repeatedly, if i step on the gas, it will just go to a higher rpm and drop. if i hold the gas pedal down or step on it suddenly i can hear the afm sucking air but it starts to die as if there is no fuel. i replaced the tps and cleaned the iscv. although, i unplugged the iscv while the truck was running and it didnt change anything. is it as simple as needing a new one? i tried another one i had and it did the same thing.
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Old 01-08-2012, 06:08 AM   #6
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Are you certain the TPS is properly calibrated?
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Old 01-08-2012, 09:59 PM   #7
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the tps only allows the truck to run all the way clockwise, otherwise it revs high then dies. the three vaccum lines on the top of the throttle body are plugged, i am wondering if that is affecting it, also, the iscv intake port coming off the side of the intake manifold is also plugged.
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Old 01-08-2012, 10:39 PM   #8
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like i said, the idle changes every 2 seconds from low to high. the egr has been deleted off of this engine. not sure what else it could be... its driving me nuts. the iscv does nothing wether it is unplugged or not it seems. i honestly cannot figure this out
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Old 01-08-2012, 11:36 PM   #9
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The TPS needs to be properly calibrated in order for the ECU to know when the throttle plate is at rest... otherwise you get a wandering throttle. If you can't get it to line up you may have the wrong model, some years have the tabs clocked horizontally and other are vertical.

No idea why you'd delete the EGR, helps keep the engine cool and doesn't affect performance at all, but whatever. If the car is a model which has an EGR temp sensor that needs to be addressed to ensure the ECU is operating properly and not setting any error codes or you can not reliably set the ignition timing.

The first port on top of North American models is the fuel pressure regulator reference and this MUST be connected.
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Old 01-08-2012, 11:41 PM   #10
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Quote:
Originally Posted by cre View Post
The TPS needs to be properly calibrated in order for the ECU to know when the throttle plate is at rest... otherwise you get a wandering throttle. If you can't get it to line up you may have the wrong model, some years have the tabs clocked horizontally and other are vertical.

No idea why you'd delete the EGR, helps keep the engine cool and doesn't affect performance at all, but whatever. If the car is a model which has an EGR temp sensor that needs to be addressed to ensure the ECU is operating properly and not setting any error codes or you can not reliably set the ignition timing.

The first port on top of North American models is the fuel pressure regulator reference and this MUST be connected.

i never touched the egr. you can blame that on the idiot who put the motor in. alright i will check that, i am positive it is the right tps.
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