4age red top high comp engine wiring help for swap. please help

[nom247]

guys im looking at a red top 4age swap, im currently just trying to get the engine started on the ground. i have the full original engine harness and ecu along with the third 12 pin connector cut from the donor car. ive searched the internet, gotten the pin layout and some instructions on startup, but i am not getting any spark from any of the leads. i have acces to the donor car and im almost tempted to just drop the engine back in the ae 92 cuz im a bit frustrated... can anyone help me please?????????

[Big T]

Check if you have power to coils first.


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[Matt]

Have a read of this thread located here (http://www.ae86drivingclub.com.au/forums/showthread.php/84165-AE92-gt-ADM86-wiring-questions) . It explains allot of the wiring gremlins you will encounter whilst putting a 4age from the ae92 into an ae86.

[nom247]

Check if you have power to coils first.


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had no power to coil or distributor... but i figured it out. had to pull the ae92 into the garage and lower the engine into it. there was a six pin connector that gouses the connection to the starter, the relay for the fuel pump etc, apparently it also feeds the power to the coil...pulled it back out but did not have time to test it on the ground.
i have another question tho, in testing i saw that the B1 and B pins on the ecu only receive 8-10v. will a direct feed of 12v be a problem for the ecu or do i need to place some resistors in line?

[Matt]

They should have 12v, if you see 8v there is a voltage drop problem.

[nom247]

They should have 12v, if you see 8v there is a voltage drop problem.


checked it today, still 8v from under dash harness, wonder if thats why the previous owner was having issues on and off. he said he would be driving and the fuel pump would just shut off. he ran the pump straight but the engine itself would cut off, he'd have to disconnect and reconnect it several times until he heard the pump slow down then start.

[Big T]

If you want a quick and nasty fix instead of chasing the entire loom, just tee in the 8v into a relay as signal and run power from the relay to the other bits you need 12v to.


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[Matt]

I'd measure the fuel pump resistance to see if there is a short causing high current draw.

[nom247]

I'd measure the fuel pump resistance to see if there is a short causing high current draw.


im guessing you were right matt... replaced the pump and all the wires, currently getting full voltage... i think that was the last of the electrical issues,, ive moved on and currently rebuilding the engine. started pulling it apart today, there are a few things i found a bit strange though. the oil drain line from the head to the block is absent. the outlet from the head has been condemned but there is no hole in the block which leads me to believe that a bottom end swap has been done. secondly, the oil pan is shaped differently, there is a bend at the back of the engine. this made me double check the block but it indeed says 4a at the front.

im wondering what car this block might have come with? are the internals the same as the block with the oil drain? what compression rate would it have, same high as the block with the drain or lower.

it has the 8 bolt crank but im not sure if the pistons are the high comp, so if any one has pics of the original redtop pistons can you post them so i can know if they were swapped out..

thanks

[phoenix]

Sounds like it's a big port bottom end with a small port head

[Big T]

Could also be a gze bigport bottom end. Does it have 3 or 7 ribs?


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[nom247]

[QUOTE=Big T;974899]Could also be a gze bigport bottom end. Does it have 3 or 7 ribs?

its got 7ribs.... stumbled on another problem... i ordered a set of connecting rod bearings but they are the wrong size. i believe they are the 40mm becuase they fit a 5a pistion i had laying around. and ever seller ive contacted either cannot verify or only stock the 40mm bearings but my crank has 42mm. can anyone forward me a link to purchase a 42mm bearing compatible with the 8bolt crank on a smallport red top 4age engine.. it would save me alot of frustration and time and be greatly apperciated.