1jz swapped RX7 questions

[WillWorkFoBoost]

So a friend just picked up a 1jz swapped fc rx7 and of course Im supposed to help him get it running right. Only having 7ms myself I dont know a lot about 1js so I have a few quick questions, tried searching and skimmed through the translated manual and couldnt find. Im gonna give it a good once over so whats acceptable compression? it puffs a bit of oil on startup and Ive heard valve guides are an issue with them sometimes.
Another blatant issue with it is since its into an rx, no one took the time to hook up cel for the rx to the harness, so i cant pull codes. where would be a good point to put in a lil led or buzzer to get blinks from cel wiring? ( does te1 and e1 pulse to do this at the diag port or do i have to get behind dash or find whatever the swapper did with wiring that went to cel?) any wiring diagrams for 1jz, maybe ecu pinouts?
In the meantime Il keep searching
Thanks.

 

[IBoughtASupra]

What 1JZ does he have? A70 or Chaser?

Twins or single?

You will need to hook up the check engine light wire to the FC engine light but I am not sure how it works on the Mazda so a wiring diagram would be useful.

How does it run overall? Any break up? New plugs are helpful if the previous owner didn't do that. Go to the JZ thread and look at the links section. I have links to verified pinouts and the 2JZ TSRM so you can get the specs for testing anything including compression.

 

[87M-GTE]

Bad valve guide seals and stock twins would cause it to burn oil

Honestly, compression isnt that big of a deal on the JZ motors, as long as they are consistant across the board I wouldn't worry too much.
Obviously if its really low then you have an issue, anything over 100psi is alright..Mine runs ~165 across the board.

 

[WillWorkFoBoost]

he checked it yesterday and lowest cyl is 175 and highest is 190. also found a a small fuel leak and 2 arcing coils haha. that doesnt help things. also exhaust goes into the stock rx7 n/a exhaust halfway back. it has twins, not sure if its a70 or chaser 1jz. thanks, il check through the jz section more thoroughly for wiring to cel etc.
thanks guys. This swap is insanely hacked and its gonna take alot of tlc to fix. someone extended the slave rod with a drillbit.... theres a piece of a bike tire around an ic pipe to keep it from rubbing. parts of the ic are crush bent exhaust tubing. good shit.

 

[WillWorkFoBoost]

So I know things like this are hard to judge and fast is a relative term.... but shouldnt a stock 1jz in an fc be pretty fast? my friend seems to think that this thing isnt running badly, but logically it should be alot faster? he also has an fc with a 13b turbo around 200 ish hp and the jz feels slower than that. just doesnt add up to me. if this thing doesnt scoot its safe to assume things are amiss with it. I dont have any experience with jzs but assuming it makes 250 or so wheel in a 2500lb car..... should move pretty well stock.

 

[rshn117]

the ecu may need to have the capacitors replaced, i would estimate i lost about 100hp at one point before recapping. other than that if the compression is good and twins arent blown it should make around 300rwhp

 

[destrux]

If it's going into a stock (2" I'm assuming) exhaust then you're looking at a pretty big power loss right there, plus with 2 cracked coils you're running on 4 cylinders under boost. Get it all fixed and you'll be doing much better. Turbo motors spew out tons of power with every mod you make, but they also lose a ton of power because of any running problems. Just tuning from the stock 10:1 afr to a 11.5:1 afr will gain 40whp or so.

 

[WillWorkFoBoost]

yea definitely robbing power with arking coils, and stock rx catback doesnt help. assuming it should make 300 wheel or nearly, and is in a fc, thing should be sideways pretty easily.

 

[hvyman]

My bet is the tiny exhaust is robbing a lot of power.

 

[Dylan JZ]

+1, my car had a pretty decent loss of power and would occasionally break up under WOT.. once I heatshrinked all the coil-packs, the difference was amazing.

 

[IBoughtASupra]

Hear shrinking the coils will work but they are cracked so you should save up for a new set, it is worth it. Curt over at Elmhurst Toyota on SF will be able to get you a good deal. Stay away from Super Spark coil packs, they have had problems.

SP in Chicago replaced a set of new super spark coils with 70K stock coils and they had no problems like the blowout with the super spark coils.

 

[Dylan JZ]

Usually I agree with buying new if something ceases to function properly, but unless I get blowout or it starts breaking up, I'll stick with my shrink wrapped ones

 

[johnd]

When my cat in the exhaust went bad the car ran fine but had no power, rev to 6k to get up to 10psi of boost.
Id look for a better exhaust.

 

[WillWorkFoBoost]

So does anyone know what pins from the ecu go up to the check engine light on a jz so I can just tap into em with an led or buzzer? tried looking at ecu diags but didnt find much that was useful

 

[WillWorkFoBoost]

So have been trying to check base ign timing on my friends 1jz and I cant seem to get a signal for the timing light, I was told it was the green wire from the ignitor but cant get a signal from it..... tried by the ignitor, and by the no 1 coil. Do I need some different light or what? Sounds dumb but Im missing something.

 

[IBoughtASupra]

What helps is if you get a old spark plug lead and then using that between the coil and spark plug, then connect the light to that. Works flawlessly.

 

[WillWorkFoBoost]

Nice, thats what I was thinking but didnt have one to try, Just figured that i should be able to do it as people said with the wire from ignitor. but Yea good call il just do that as its easier anyway.