Reddraco

Hi all, Names Jon.

I just bought a Red 1988 rx-7 with a T2 motor swap. Picked her up for $2,200.(Pics Coming soon).

Post on the Car with all specs. http://washingtondc.craigslist.org/n...718035950.html

I Bought a new radiator hose, battery. Did oil change.( Had ATF in her).

Got her Runing but Very rough.. She smoked like a Beach at first. but now shes good.
The Bad: Shes Runing VERY rich. She wont Stay idling. If I start her with out pedaling. She will die in 3 sec. Also if I feather the pedal, i can only give her 1/10 Throttle to 1/8( rpm range: 1500-4200). Other wise she bogs down an dies.
Full throttle she revs to 4k very roughly and misses.

What I do know: The motor Was bought from Tigerjdm. T2 S5 motor/Trans. The ECU was swaped by someone who I used to know. Hes REAL **** about getting things right. (So Im hoping the Wiring was done correct, So far everything works).
Shes got Good compression, 6 puffs. 84-88psi. There isnt any Smog/Evap system on her. Almost all Vac holes have been pluged. She dosent have any kind of Map sensor, O2 sensor Hooked up.( Wich i think is part of the problem). Also I Ohmed out the TPS and on a-b it has 7.55k resistance. on a-c it has 7.3k resistance. All data spec says should be at 1ka-b and 5ka-c + or - 1k. Can that Cause All of this?

What I dont know: Were All the Frigging wires go. Weather the AFM is for a turbo or an N/a. Proper Firing order. ( Is LEAD 1 Top or Bottem? Also is Rotor #1 closest to front of vehicle, an Rotor # 2 closest to fire wall?).

What I need: Pin out/location of all wires dealing with Air fuel reading.
Also about the Coolant Temp sensor Were and What color wire?. In some car's if the CTS isnt hooked up the ecu reads its like -40 deg F out side an DUMPS fuel..

Thanks in advance for the Help. Lets get her Spitin fire

RotaryRocket88

iTrader: (7)

This is going to be difficult due to the fact the the engine is from a different series car. From your TPS values, I'm going to assume this S5 engine has S4 sensors & an S4 ECU. An S5 TPS would have 2 plungers and 6 wires. There is generally no way to mix S4 & S5 electronics. As far as the reistance values, yes those are way off. The A-C 1k ohm value is what you should see with the engine fully warmed, so the throttle plates have settled. Part of the cold start system (the thermowax & cam) prop the plates open.

Now for the other things:

1) The compression numbers are a little low. 85 psi is the minimum spec in the FSM, so the life expectancy of this engine may not be very long. If you didn't prop the throttle open during the test, this can cause numbers to drop a little.

2) It has to have a MAP sensor, and it needs to be from the same series as the ECU. Look for a black sensor on the passenger shock tower. Get the part number, and I can tell you what series/model it came from. N318 is S4 TII.

3) The O2 sensor isn't used for anything other than cruising mixture adjustments. At idle, it is not used.

4) Leading plugs on the bottom & trailing are on top. There are "L"s and "T"s cast into the rotor housings for reference. Rotor 1 is at the front of the engine, and rotor 2 is at the rear.

5) For the AFM, again see if there is a part/model number on it. If it's black and circular, it's from an S5. If it's silver and squarish, it's from an S4.

6) For the ECU, check the model number. N332 or N333 will be S4 TII, and N370 or N374 will be S5 TII.

7) The water temp sensor is on the back of the water pump housing.

8) Pin outs: You'll need to figure out what model ECU you have, and what wiring harness was used before you can reference the FSM wiring diagrams & fuel/emissions sections.

Reddraco

Thanks Rotary,
Turns out that it is an S4 swap. The TPS is One Plunger 3 prong. Also I found The Map sensor. It is n318. Also Found the CTS. I ohmed the CTS, and N318 using All data. They are in spec.
I unplugged the TPS sensor an she Ran 500% better, even with Boost leaks. LOL

As far as the ECU, Were is it located normally?
Compression: I didn't Prop the Throttle open on the compression test. Ill have to do that an see if It makes a difference.
I went threw the car earlier an wrote a Fail sticker for my self. For inspection Im going to need a mid pipe, 3in-2/12. And im going to have to figure out the wiring. I have DTRL, Brake lights. revers and thats it. head lights pop up but are unplugged... So at this point I need to Look for the ECU.. lol

Other then that The car is solid. New Tires/rims. Coil overs. Brakes are upgraded and Good Pad/rotor life. No leaks. The Body is unbelievably clean. Interior is Beautiful.
Im excited, Shes going to be a beast.. Her name is Leviathan.

RotaryRocket88

iTrader: (7)

The ECU is under a kick panel under the passenger-side carpet. Once there, you can inspect the wiring to see if anything looks modified. Take a look through this thread to get an idea of the typical changes for S4 to S4 TII swaps: https://www.rx7club.com/2nd-gen-archive-72/s4-na-turbo-swap-details-813825/. It's in my sig too, but I think you need more posts to see it. There are 2 ways to go: modify the NA emissions harness, or adapt a number of harness junctions to use a TII emissions harness. The first is the easiest.

For the TPS, it sounds like you just need a new one. They can cause all sorts of odd behavior.

Reddraco

Update: Finally got a hold of the guy who did the swap. He swears its an S5 conversion. So now im back to square 1. How does an S5 have an S4 TPS sensor on it? I guess ill find out tomorrow whether the new TPS I ordered will make it run like sht again.. LOL

By the way Great Write up. Thanks!!

RotaryRocket88

iTrader: (7)

Your MAP sensor and TPS are S4, so it's definitely not all S5. It could be S4 electronics on an S5 block. It's the simpler way to put an S5 engine into an S4 car. The other way is a wiring mess, so a lot of people avoid it. If you post some pictures that show the front cover, water pump housing, manifolds, etc... I can tell you what's what.

Reddraco

Update: Been under a heavy load at work an home. sorry for the delay.
ECU: she has a N374 so S5 ecu. Also I looked at the paper work from Tiger jdm. It is an 89-91 13b-rew. So Guess that puts that to ease. Definitely an S5 motor/ecu.
The TPS: I ordered her, installed her and adjusted her using ohm meter.. Ran Like SHT! Wouldn't go above 4k again.. Runing Stupid rich an hot. So I took it off an returned it.
2nd day to an from work... Runing Hella lot better..
I did find some Vac/boost leaks. The JDM motor has plates on the side of the Intake Manafold were some Smog stuff used to be. Well there are NO gaskets there. If you Spray Gum cutter at them the idle goes from 700-900 loap to 2k...

Also have a Question about Boost. I bought a gauge but haven't installed it yet. On the Turbo- It has a Metal Vac/boost line Runing from The End on the Turbo outlet (Charge Pipe) To the Wast gate Actuator. It has a Metal T in between. It Looks Factory. But on the T There is a cap. No Vac/boost line running anywhere.. Nothing... (Charge Pipe to WG). If im right that means the WG is Open almost 100% of the time and It isn't allowing the Turbo to Fully Charge . Right? or am I hiting full Boost with WG open?

To give you a Seat of Pants Diag: Shes FAST! I HAVEN'T hit fuel cut. She seems to LOVE Any kinda throtle I give her. No studer or hesitation after 1/10 throttle. Just absolutely AMAZING acceleration! I havent Gone above 6k for fear I am Over boosting.
Also starting to think she might be Bridge ported / or maby even chiped... She seems WAY to fast for 200hp... I came up to an srt 4 at a light. Gave Her I think maby 60% an ended up 2 cars at 60mph. 3/4 Throttle and Shifting into 2nd at 6.1 -6.2K ish.
( I know when I get 1 hr to my self an finally hook up the boost gauge ill know for sure were i stand, but that will be Sunday LOL)

Guess my Question is What sensor actually Controls boost. And how the hell did I smoke a SRT-4 with out even trying LMAO...

BTW: RotaryRocket88 Thank you for you help man! You have truly Given me a Good Standing point on this beast!

alex ruano

pictures pictures

RotaryRocket88

iTrader: (7)

Well, if it has an N374 ECU, there are now more questions than answers. That's a j-spec S5 ECU, but your TPS and MAP sensor are apparently S4. These can't be mixed. Also, the importer probably messed up the description since a 13B-REW is a 3rd gen engine. It would be pretty obvious if you had an REW in there, as it would be written on the manifold, you wouldn't have a top mount intercooler, and you'd probably have twin-turbos (unless removed in favor of a single).

As for acceleration, even in stock form a TII is pretty quick. Throw in a better intake and exhaust system, and even with stock-ish boost levels, you'll be making power than stock. There's no sensor that controls boost. The wastegate controls boost primarily, but on S5s, the turbo duty solenoid works as a boost controller. The wastegate spring is set for 6 psi, and the controller brings that up about 8 psi.

Something else to consider is that N374 ECUs are frequently modified, so the fuel cut feature may have been removed. You may be running more boost than you realize, and it's not at 6k+ RPM that it would happen. Boost peaks around 3.5-5k RPM, then declines towards redline. The stock turbo is actually on the small side for the engine, so it spools quickly and brings a big wave of torque, but it fades up to redline.

Reddraco

Ah very nice. Thanks Man. I got the Boost gauge hooked up. And Like you sayed it Spools very Quickly, hits 8psi an stays there. As far as the TPS, that makes sense. Like I sayed I bought a New S4 an pluged it up an it ran like she had 5 dead rotor ports lmao. Im runing with out one now. The only issue im having is rich idle. I do have the N318 map sensor hooked up to the Intake Manifold. Some one sayed that could cause (boost creap). What is that?
Also How would I find out if the motor is bridge ported? I watched a video of a Bridge port. an apparently they loap real bad. Like mine does..

Reddraco

Link to Pics

https://www.rx7club.com/2nd-generation-non-technical-pictures-198/pics-new-t2-rex-903872/

RotaryRocket88

iTrader: (7)

As I said, N318 is an S4 MAP sensor. If your ECU is S5, you need an S5 MAP sensor. Try the classified section of this forum.

Without a TPS, idle and low throttle will be affected. You'll want to get one. You may also have an aftermarket fuel pump driving up fuel pressure, which means excessively rich idle.

You can't really tell if your engine is ported by looking at the outside. A mirror inside the intake ports might show you.