eraser13bt

I am going from a USMD S4 motor to a JDM s5 motor, including the S5 ecu. The shop has done some harness swapping and all the other little things to make this swap work. Apparently i did not do enough research prior to venturing in this direction and far to late i have gathered from other local shops ( Atl) that this swap is very rarely pulled off. Well the car starts and Idles fine ( from what i was told it sounds like a beast). If you hold the pedal down less than a 1/4 way it will rev fine. Any thing over 1/4 way it spits and sputters and backfires and attepts to die. The guy doing the swap actually had to go out of town so i figured i would check around and see what people had to say, see if anyone had any ideas. I thin kits a TPS issue, but that is me. Any one on here with a S4 with JDM s5 motor?

HAILERS

Well. Disconnect the TPS and see if it still does it.

Big88chevy

iTrader: (5)

U prob havnt gotten advice cause i guess were kinda looked down upon for doing the infamous s4 to s5 swap.

I also started my project thinking i knew more than i actually did, I paid for it in the end. A microtech solved all my problems by taking away all the bs so i would say just look for a cheap one on the forum. I went from an s4 n/a to a jspec s5 so i was in kinda a different situation but its close to the same.

XSNRGE

Sorry to come off as semi-off-topic, but I'm kind of new to RX-7s and wanted to know what all the fuss is about swapping a USDM S4 NA engine to a JDM S5 engine? I've also read that its more difficult to install a turbo system in a normally NA 7, and its recommended that its cheaper selling it and buying an already turbocharged TII. Why is that?

arghx

iTrader: (3)

^ basically you have to match up a bunch of wiring (and having a JDM engine doesn't help either) which makes it a pain in the ***, that's the short answer.

Big88chevy

iTrader: (5)

yup hes is pretty much dead on. Unless u have all your resources available for fairly cheap, its a lot easier to just by a T2. I attempted to do the wiring myself and finding the wiring diagrams needed was a month long task on its own. I ended up with just going the route of a microtech lt12 cause it was worth the 1000 bux.

Icemark

TPS and Timing should be checked first.

and eraser13bt your bumps have been deleted. Bumps are forbidden here in the 2nd gen technical section.

eraser13bt

sorry they were not ment as bumps it was more of me being frustrated. any how i talked to someone who is one of the few to have pulled this wap off correctly. and it is jdm s5 motor. from the symptoms i described to he he thinks its the omp, i had the shop remove it but if i remember correctly it has to be plugged in on the s5 or it will put it into a limp home deal. he told me to have them check the omp, tps, then the ecu. sorry for the poor grammer and spelling i am on my pda and not my laptop, so no spell check.

MidnightOwl

What shop did the work?

MaczPayne

iTrader: (5)

I have an s5 JDM motor in my s4 TII. Getting it to work was easy since I had standalone engine management.

Icemark

a bad MOP will result in a check engine light if you are using a S5 ECU and harness and result in the ECU running in Limp mode.

The swap can be done successfully, you just need to decide if you are using S5 engine harness and ECU and modifying the cars wiring and harness wiring to work, or if you are using a stand alone, or if you are taking a S4 ECU and harness and tweaking it.

RotaryResurrection

iTrader: (8)

http://www.rotaryresurrection.com/2n..._s5_diffs.html

SirCygnus

iTrader: (1)

bullocks. the shop reamed you on the deal if they handed you a car that didnt work.

on the other hand, i would simply suggest reverting back to s4 electronics, and then just block off the unnecessary bits.

eraser13bt

No no It is still at the shop. I am using an S5 JDM ECU, S5 wiring harness ( USDM) and a JDM S5 Motor. The car is still currently in the shop, the guy actually doing the swap had to go out of town this week so while he was gone i decided to do some research and help out a little. The shop itself comes highly recommended.

This is what i think is happening, For it to idle fine and rev well at under a 1/4 throttle, I personally feel like it is a Limp home mode that is not allowing it to rev hard, ( or am i completely off base?)

eraser13bt

Main stream performance, Like i said before they came Highly recommended. Aso corrected it for you.

RotaryResurrection

iTrader: (8)

could also be a secondary fuel injector not firing, since the primaries are only used under light/mid load.

eraser13bt

They said it was getting plenty of fuel, but ill tell them to check that out also thanks.

RotaryResurrection

iTrader: (8)

Just because it is getting fuel at the engine, does not mean it is going into the engine under load, otherwise you might not be having such a problem under load.

eraser13bt

Ill tell them to check it out when he gets back in town.

phoenix7

this is why, WHEN YOU SEARCH, people always say:

"for plug-and-play action STICK WITH YOUR CURRENT SERIES" Check their work using the FSM and fix it or tell them to give you a running car. Look at teh TPS and timing as mentioned above, check the fuel also.

hope you didn't pay too much for it.

eraser13bt

^^^^ Once again the car is still in the shop, the Tech who was working on it is out of town. Prior to leaving he called and told me about the problem. I thought of a couple problems that could be causing it but i wasn't sure. So i decided to ask you guys, and while there have been some helpful post most have been slamming the idea of doing the swap or the shop doing it. Sorry i wont let is happen again.....