1JZ Big single swap running horribly, #5 misfire and driving me nuts!! PLEASE HELP!!!

1JayMK3

1JayMK3

New Member
Jul 15, 2012
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Swift Current, Saskatchewan.
I've read for roughly 4 hours trying to find other situations like mine but I am finally caving in and trowonr in the towl. Please someone help me!!!!

I'll give a quick summary of the car.

1986.5 MA70 car, had a 1JZ swap when I purchased it. BPU's and ran amazing. Few week before December I went to park it and it didn't want to run, I finally tore into the computer and found my issue, leaking caps. Had the caps redone and it ran amazing. Pulled it out of storage this spring and still ran great and then we did the year down.

Removed the twins/old junk and threw on a Borg Warner S366. At this time all I did for now was instal JDM 440s , sard afpr, apexi neo safc, AEM tru boost and fuel pump/all the single parts required for the swap.

After a week of working on It last night we finally we able to fire it.

Crank it and first try it fires then dies instantly, alright that's fine. Try again, nothing but cranking. Checked over EVERYTHING.

The car had air, fuel, spark but wouldn't even fire just cranked. Eventually sprayed a little ether into the intake and it fired but on roughly 3 cylinders. Missing horribly, quickly set my afpr to 45ish lbs at idle.

The car started to smooth out a bit but it won't fire on #5, it has spark though.

Only producing roughly -14 vacuum but thinking the misfire would also lead to this issue but can't figure out the misfire.

Will be doing an injector ground check today and checking the noids as well. Will also plug in the 4th and 6th injector plugs into the 5th and see if that works. Not sure what else to check over....
It was fine until the injectors were done, nothin else could cause this I don't think?? Please someone give me some JZ knowledge or lead me in the right direction.

Thanks everyone!!

P.S. sorry if spelling errors. Typed this whole thing on a stupid iPhone, sigh.
 
1JayMK3

1JayMK3

New Member
Jul 15, 2012
37
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Swift Current, Saskatchewan.
Put in stock injectors and now is firing on all cylinders. But the car is still running like shit. Extremely rich at idle (10.0) I have no effing idea.

Check everything, even unhooked my neo and still running bad. Throwing a CEL but no codes are present...
 
525gte

525gte

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Sep 19, 2011
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hoquiam
Does the car have stock cams?. Sounds like too much base fp.. when I did my 440s in my car I had one bad one also
And you will have to tune the afc. Try to lower the base fp or maybe you can try to make adjustments at low rpm on the afc
 
1JayMK3

1JayMK3

New Member
Jul 15, 2012
37
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Swift Current, Saskatchewan.
Lowered the base FP all the way down to 15 and nothing. Pulled a shit ton of fuel with the safc and still 10.0's. Plugs weren't to bad at all.

Finally thought I would pull my computer apart just to see and this is what I find.
8931994347_a8e8c38a14_h.jpg


Another two leaking caps!! Now that I think of it all the issues I am having right now are almost the exact same as last time when my cap was leaking, extremly rich, poor idle, always feels like it's under load... From reading it sounds like the caps pretty much dictate what the injectors due?

I'll be getting it fixed this week so I am praying (Fingers Crossed) That this fixes the whole shabang!
 
1JayMK3

1JayMK3

New Member
Jul 15, 2012
37
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Swift Current, Saskatchewan.
Update...

Got the caps fixed, car fired up and ran perfect!!! Drove it for roughly 30 minutes, played with the Safc and did a few pulls and ran incredibly.

Bring it back to the shop and leave it turbo timing then randomly it starts to miss and pop. Shut it off for a bit and fire it back up and runs great again. Go to drive it home and it all happens again, missing, back firing, everything. I am honestly thinking the computer is my issue, heats up and causes the misfire?

I'll be testing a stock computer on the car next week and we will see. Does anyone else have any ideas? Plugs fowling? Bad cool packs? Anything that may ring a bell before I spend lots on a computer?

This is a video of the issues
play
 
f00g00

f00g00

Supramania Contributor
Jul 2, 2007
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Kuwait
Any smoke? Mine did something similar where it went pig rich and it was the PCV valve.
 
IndigoMKII

IndigoMKII

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May 9, 2011
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Madison, Virginia
Car sounds good when the ecu acts right. What could be causing the caps to pop often is too much load on them? Have you checked the resistance for your harness to the injectors? Does the ECU get really hot after running for awhile?
 
525gte

525gte

New Member
Sep 19, 2011
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hoquiam
Check the wire harness at the plug of the water temp sensor. Make sure none of the wires are green or broken

My did this also.. random misfire run like shit. And it got worse over time. The problem was bas wires at the water temp sensor
 
1JayMK3

1JayMK3

New Member
Jul 15, 2012
37
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0
Swift Current, Saskatchewan.
f00g00-Just black from it being 10.0 and dumping endless amounts of fuel into it without being burnt, The PCV valve is currently out of the valve cover and just routed to my catch can, have seen a lot of people running this set up with no issues at all.

IndigoMKII- That's the strange part! It felt like it ran strong when it was running well, minus not making power till 5 grand with the huge turbo it was a freight train till redline. I haven't checked the resistance yet, can you give me some numbers I should be comparing mine to when I check or a how to? The ECU was quite warm yesterday when removed BUT here is another catch. My car is a LHD car with a JDM harness, this means the harness isn't long enough to mount in the cab of the car so it's currently mounted on the firewall area so in the past with the prior owner the ECU saw a lot of moisture and heat. When I got the first cap originally replaced I cleaned out all the corrosion, put dialectic grease on everything and made sure it was clean. I spoke with a huge tuning shop in Calgary, Alberta today and they figure that the Injector Drive in the ECU is shot OR the coil packs need replacement asap. Inspecting the coils I can see wear on them, cracking, etc. Common out of 20+ year old plastic parts...

I guess come next week throwing on the working computer will answer a lot of my questions about what's going on and hopefully that will solve this issue!!



525gte-Will take a gander right now and see if I can see anything out of the obvious. I know I had to remove these sensors when I did the single swap so maybe a wire broke when it was removed?
 
1JayMK3

1JayMK3

New Member
Jul 15, 2012
37
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0
Swift Current, Saskatchewan.
Tugged on them, the only one loose is the single wire one that goes to the gauge while the two wire one is solid. Here is a picture, it is quite dirty though as I haven't had it running long enough to go wash everything off.
8983052000_5c754f87f9_b.jpg


I also took my computer all apart again to look, while looking I have been looking at the board where the original capacitor was leaking before winter. I had it replaced and ran the car but only for 10 minutes so really it may have still been wrecked and I just didn't run it long enough to find out. It was quite burnt where it leaked out originally (On R264). I also noticed though right above the cap a resistor looks almost like it isn't making any/not enough contact to the board, pictures to follow
8982996946_f84664a94e_b.jpg
8982979110_83135f8464_b.jpg


I went through a bit tonight just double checking, all the coil packs look fine, no cracking or anything out of the ordinary. Plugs look good and tips aren't bad at all. Wiring to them looks good as well.
 
525gte

525gte

New Member
Sep 19, 2011
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hoquiam
1JayMK3;1944459 said:
Tugged on them, the only one loose is the single wire one that goes to the gauge while the two wire one is solid. Here is a picture, it is quite dirty though as I haven't had it running long enough to go wash everything off.
8983052000_5c754f87f9_b.jpg


I also took my computer all apart again to look, while looking I have been looking at the board where the original capacitor was leaking before winter. I had it replaced and ran the car but only for 10 minutes so really it may have still been wrecked and I just didn't run it long enough to find out. It was quite burnt where it leaked out originally (On R264). I also noticed though right above the cap a resistor looks almost like it isn't making any/not enough contact to the board, pictures to follow
8982996946_f84664a94e_b.jpg
8982979110_83135f8464_b.jpg


I went through a bit tonight just double checking, all the coil packs look fine, no cracking or anything out of the ordinary. Plugs look good and tips aren't bad at all. Wiring to them looks good as well.
Click to expand...

Clean that connector off may be broke under the dirt

And what kind of plug are you running?
 
IndigoMKII

IndigoMKII

New Member
May 9, 2011
2,181
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Madison, Virginia
Honestly, I have no hard numbers to tell you about the resistance. You could measure the resistance of the wires to the injectors/coils and see the resistance in the wires themselves.
 
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