thewird

iTrader: (8)

Ok, so I own an 93 RX-7 and decided I wanted to try my hand at rebuilding a rotary engine. I have zero mechanical knowledge but can do anything with instructions. So I got Bruce Turrentine's video's for all the work and it seems like something I can do in my garage. I found a decent condition 88 RX-7 for my needs. So I've had the car for about a week and its took a while to go through the initial diagnostic stages since my battery booster had to be recharged all the time. Also, due to the fact that I lost the key and had to figure out how to crank the car without a key (pretty simple, just pull out the ignition).

So after trying to get the car to start with starting fuel and cleaning the spark plugs with no success, I decided to do some compression testing. My first set of compression tests came out 50 psi on the front and 30 psi on the rear. Since the car hadn't ran for a while Jim recommend I put some 20/50 oil in it. I bought the oil thing and put some in through the spark plug ports. Then I ran the compression tests again (my hands started to hurt at this point from all the screwing). This time I got 90 psi on the front and 55 psi on the rear. Ok, so the rear rotor is blown but do you think it will start in this condition?

So if the rear rotor being blown is the only problem with then after I rebuild it, it should work (assuming I don't do a horrendous job). The engine is an JDM s4 Turbo swap on an 88 body. The wiring harness was done poorly but it worked at some point so there might be some problems.

Here's some pictures (click for higher res pictures)...

Can anyone tell me what the hole to the right of the 099 is for?





thewird

B6T

iTrader: (2)

The reason it won't start is because you don't have the intercooler plumbed into the intake system properly. These cars run on an air-metered system that uses a mechanical flapper door which switches on the fuel pump once air is drawn through and the door is opened. Without the intercooler plumbed into the system, the engine is open to the atmosphere and not drawing air through the air meter. It would be like trying to drink through a straw without the straw in the liquid.

Using your picture as reference, if you rotate the intercooler 90 degrees CCW, you will find that the two black hoses on the engine interface with the inlet and outlet of the intercooler.

The hose with "099" on it should slide over the silver aluminum pipe that is parallel with "Rotary TURBO WITH INTERCOOLER". Once you have that connected, the other pipe should line up with the rubber hose on the throttle body (seen to the left of your compression gauge in the second picture).

The hole to the right of the "099" is a fitting that draws air from the air box into the air pump.

thewird

iTrader: (8)

The intercooler was actually bolted on correctly, I just removed it to try injecting starting fuel directly into the engine intake. I guess that was a bad idea. I'll try reconnecting the intercooler back in tomorrow.

So that hole to the right of the 099 is fine like that or I need to find an air filter for it etc? Thanks.

thewird

B6T

iTrader: (2)

You don't need that line connected.

justicejayant x

Yes man.

Terrh

iTrader: (7)

Judging by that engine bay, that car is not a TII. Someone's crammed a turbo motor in there, but it's not kosher.

AFM's don't like to work on their side. Not a starting issue, since they'll start without the MAF at all.

The reason the car won't run is because that car is a horrible hackjob. Look at the wiring harness. It doesn't even route there! It CAN'T even route there and reach the things it needs to reach. I don't even want to know what that harness is out of.



When we leave for deal's gap, I'll let you poke around under the hood of my stock 10AE and take some pictures or whatever, you can see how it all fits together.

55PSI rear rotor is not necessarily blown. Did you put anything into it yet? I'd try and jam as much diesel into the spark plug hole as you can get in there. Rotate the engine with he plug out and do it again every 2/3 of a turn or so to get all the faces of the rotor wet with diesel.

You're probably going to need a full wiring harness too. I might have a used one, I'll look into it if you want (shoot me a PM), or you can get new ones from the mazda dealer, but they're like $700+. I've bought one and I'm not sure I'd want to do that again.

thewird

iTrader: (8)

The body is a N/A body with a JDM turbo inside it so your right. Would a USDM wiring harness work on a JDM motor?

The wiring harness is the funniest thing you could ever see. There's wires all over the place and some have multiple splices using different cables. It somehow works though or at least used too lol. I didn't have time to drain the gas yet but I bought the gas tanks for it and a proper jack.

thewird

Terrh

iTrader: (7)

a USDM harness will work a JDM motor.

They're basically identical.

I can't tell from the pictures if that is an S4 or S5 motor but it looks like an S5 intercooler. But there's an S4 maf. So I really don't know. Everything needs to be S4 or S5 though, you can't mix and match or it won't work. (even the intercooler - if it's stock, the lines are different on an S5 one than an S4) and NONE of the electronics are compatible except for some of the solenoids and the knock sensor (which is useless anyways).

Does it have an electric OMP or a mechanical one, with a linkage that goes to the throttle body?

If that were my car, I'd totally rip it apart and then start putting it back together correctly, who knows what else is wrong under there.
I'd be really surprised if that car ever ran with that motor and harness in it.

thewird

iTrader: (8)

It's supposed to be an s4 motor. The car basically has no accelerator. Its not connected or mounted at all. I was planning on worrying about that later once i either got it working or rebuilt.

PM me about your wiring harness but I have the JDM ECU (I have the USDM N/A as well), I don't think those are compatible. Could be wrong though.

thewird

Terrh

iTrader: (7)

the N/a ecu is useless to you.

if it's an S4 motor and you have a JDM S4 ECU you need an S4 TII harness. I'll look around and see if the one I have is decent.

IAN

iTrader: (3)

Since no one mentioned that hole by hose 99 is for the air pump. usually comes from the TID. (Air intake piping) IF it is running open like that the pump will seize. Its for emissions. Air pump to cat converter.

Yes buying someones work sometimes makes you wonder. Hack jobs everywhere.

My brother bought a REW twin turbo fc totally custom. IT was a joke. (It was fast. He did own me from a start. At least until I grabbed second gear ) He owned it for two months, blew the motor and will never look at a rotary again. I could go on forever with what was wrong. I spend hours and days correcting but it was not enough. (None turbo pressure sensor and it was not even connected)

its been some time since I had a stock FC but I may be able to help you abit.

Also I would like to build a motor one day. I have 5 engines stripped, some cleaned, and ready for rebuild but have not decided if to get a shop to do it or save some money and learn how to do it myself. (Still need porting items and engine stand) My first engine if I build will be stock seals. Next one will be ceramic.

Post pics of your engine rebuild.

See you in two weeks!

Ian

Nismo Convert86

iTrader: (7)

Yup Ian I totally agree, that car is still a curse, the body is crap, the wiring is crap, it's not much of a car, in the end you are almost better off buying an unmolested specimen, and going from there, might cost more in the end, but you can enjoy it more if you don't have to do rework and chase down wiring issues. Thats why I'm looking for the almost perfect FC so I can start over, and do everything right.

It looks like you are off to a good start, and the best way to learn is by asking questions, and getting your hands dirty. Do you know if the electronics were swapped over for the TII stuff? Like the AFM, Boost Sensor, and such.

B6T

iTrader: (2)

It's not necessarily a good idea to get a new car. He probably got this one for a good deal, and getting rid of it will only reduce the number of 7s out there on the road.

Even if it is a huge hack-job, it's still salvagable. It just means he'll get more experience replacing everything!

thewird

iTrader: (8)

I think they should of been but being honest I really don't know. I'm gonna try starting it again with fresh gas this afternoon.

thewird

thewird

iTrader: (8)

I was hoping it would be a rebuild only project but looks like the project might be expanding

thewird

Nismo Convert86

iTrader: (7)

Well from a conservation stand point yeah you are right, but if you have ever had a cluster as bad as the car Ian is referring to (now my car) you would think otherwise. When you have to replace everything it's really not the best thing, you get frustrated with the money you are spending, and time you could be enjoying other hobbies, or with family and friends. But the RX7 will allow you to work in all fields over the lifetime of the ownership.

Well the ECU should be N332, or N333, the boost sensor/AFM should both be N318. That should give you an idea of if it was swapped out.

thewird

iTrader: (8)

Well I drained the gas and fuel lines and put in some fresh fuel. Boosted the car directly from another car for more juice, and starting cranking. It gave a little sign of life every few strokes. My guess is from the 2 strokes that actually have compression. But in the end it did not start.

So now its time for the rebuild. I need to change the car to my name first so I can put it in a corner.

Nismo Convert86: I'll check those sensors tomorrow.

thewird

TalkSick

fwiw check for obvious vac leaks.. i know its tricky without the car running but if u have a large vac leak the car will not start.. it wil give a sign of life every so often but wont catch. take a quick look aver everything an make sure its all tight n connected. i wasted a full day i minus 20 celcius tryin to start what i thought was a frozen 7. after pull starting it to life i could hear those lil nuts that hold the intake piping to the throttle body rattling. seems id forgotten to tighten them. by the look of what you are dealing with id say something like this might be a distinct possibility