Th0m4s

I've got a big probling i'd like to hear your opinions and advices on. My S4 RX7 FC T2 wasn't running for about 8 months now because of a sucked in front cover o-ring and a broken stock turbo which was pressing all my oil into the coolant.
I decided to put on a complete T04b turbocharger together with a FMIC , a new 3" downpipe which i welded on my own with a 100cpi catalysator and a Bosch 044 fuel pump. Needless to say i replaced all the seals in the front cover, too. I also deleted the whole rats nest and replaced the S4 LIM with a S5 one because it was cracked. An S5 one because in Germany spare parts are really rare for these cars and that one was the only one i could find. I'm also using a Tial 38mm wastegate and a closed circuit Forge blow off.

I have to say the car was running fine 8 months ago and even 4 months ago when i removed the air pump but before i removed the rats nest.

Three days ago i tried to start the car because i'm more or less done with the mechanical modifications. At the moment it still has the stock ecu, afm and water cooler but i'm going to change that in the next weeks. I only first want to clarify the car is running so i can waste more money on it.

Back to my problem now: The car was very hard to start. I thought it was maybe all the garbage in the exhaust and so on after standing such a long time but it wasn't. The car is always hard to start. Last time it took me about 20min to get it more or less running and when it's running it's only running on one rotor i guess. It idles at 700rpm but it's shaking like it's running on 200rpm or so. The funny thing is if i floor the gas pedal it runs crappy till round about 4000rpm and then the second rotor comes on and it starts running like hell till red line. I'm absolutely sure the wastegate and blow off are working as intended btw. AFRs are OK, too. In between 11,5 and 13 all the time. It's running on 7psi at the moment because i don't want to blow anything.

So as long as i keep the rpms higher than 3800rpm it's running great. If i let the engine go down it start's it's horrible shaking again and sounds like a lawn mower (i mean much more than a normal 13b would sound like that ) but it holds 700rpm perfectly without any help.

I allready tried to change the primary and secondary injectors against eachother to see if the problem moves up to the higher rpms but it doesn't. I also checked everything for forgotten vacuum lines or false air. Nothing. Today i checked the fuel pump and fuel pressure and it was ok. I also did a compression test and that was ok, too.

I'm wondering if i maybe accidentially harmed one of the wires for the primary injectors so one of them isn't opening. Could i test that in some easy way? I've got everything but an oscilloscope. If one is broken i'd like to rewire them but where would be the best place to cut the old wires off?

By the way what would a misadjusted CAS cause? I'm pretty sure i placed it like it was before but who knows...

walken

iTrader: (6)

you've already upgraded the turbo so go standalone. upgraded boost on the stock ECU even at stock levels will silently damage the engine.

Th0m4s

That's what i'm planning to do next but i first want to get the engine running before i spend more money in the car.

AGreen

iTrader: (11)

If you messed with the timing (CAS) then you need to properly adjust it before driving the car. You need to verify the timing using an actual timing light.

The reason I say "actual timing light" is that I had a friend of mine take his truck to a shop to set the timing. He gets his truck back, still runs like crap. The poor guy just couldn't figure out why his truck was running so bad and overheating. He brought it to me, and the first thing I did was verify timing. 17 degrees advanced. The timing marks weren't visible for all the dirt and rust on the pulley. The "initial set coupler" on Fords is a plug you have to disconnect, it was very apparent that it hadn't been touched. So, he gets his truck back and it's running great. He goes back to the shop to complain, and all they could say was "look, we're 'old school', we don't use any of that fancy computer stuff, we set it by ear".

WTF! They charged him for that, and risked destroying his engine at 17 degrees... 17 DEGREES advanced!!

Th0m4s

Hehe exact torque in their fingers and timing in their ears.

Can i even adjust the timing without the engine running? Only thing i could do so far with the CAS was screwing it back in in exactly the same position it was before i pulled it out. Can that really cause my problems?

By the way i changed the ignition coils today for known working ones. I also tested the injector wiring. All 4 green wires at the ecu carry 12V so i guess they are ok.

The strange thing is if the car is standing for one or two hours it starts with the first try (still running on one rotor but it starts). If i shut it down then and try to restart it, it only ignites one or two times and then it only turns without any ignition.

I'm running out of ideas soon...

AGreen

iTrader: (11)

That won't tell you if you have properly working injectors or not. The absolute definitive way of checking them is to remove the upper intake manifold and check with a set of LED lights at the connector that they pulse when cranking. Testing for 12v at the ECU will only tell you that you have 12v coming from the ECU. It does not account for good wiring. Also, the injectors have 12v when the key is on, at all times. The ECU pulses ground to them.

Now, as far as verifying the CAS and timing, you need to do the following.
-Remove CAS
-Align the eccentric shaft pulley and front cover pointer to the 5ATDC mark.
-Remove the top cover from the CAS
-At the bottom of the CAS, align the dot on the drive gear to the notch on the CAS body.
-Without moving the gear, carefully install the CAS.
-Reinstall the cover
-Start the car, warm the engine up.
-Jumper the initial set coupler
-Set the timing using an inductive timing light on L1 spark plug wire and the 5ATDC mark.

K-Tune

iTrader: (26)

Sounds like the fuel injectors are plugged in wrong.

flaco

iTrader: (7)

a clogged primary injector ,bad injector or bad connector

Th0m4s

I tested the injectors allready. They are working and the wires are ok. the green ones all carry +12V at the ecu.
How can i find out easiest if an injector is plugged in wrong?

Stupid question: Might it be a fouled spark plug? Didn't even think about them last week.

cody27

You never know sometimes with spark plugs, I would replace all the plugs just to eliminate that possibility.

junito1

Had.this.happen. its the injector plug or injector. If youre so sure the injectors r good then change.the injector pigtail.

Th0m4s

I just found out that 2 of the 3 chambers of the front rotor have a bad compression now. I guess one apex seal got stuck because when the car was running last time everything was ok and 8 months later without running it lost it's compression. The seals are all still there without any damage as far as i could see and feel when i mounted the exhaust manifold.

I put some carbon cleaner in today. Maybe it helps.

AGreen

iTrader: (11)

Warm the engine up all the way and suck in a gallon jug of water in the intake manifold. Just get a long vacuum line and connect it to a vacuum port, dip the other end in the jug, rev the engine to about 2k. This will steam clean the carbon off the rotors.

Th0m4s

I was able to get the seal moving again. Now the compression is back buuuut now the engine is running extremely lean under partial load. It works perfect if if floor the pedal but under partial load my afr-gauge can't even show the afr ratio because it's too lean and the car is sputtering and still running on one rotor at low rpms.
What the hell could now be wrong?

junito1

partial like extremely light load... i think thats normal.. but dont hold me to that. sm1 will chime in.

And good job on getting the seal loose.=)

satch

iTrader: (1)

Are you sure the spark plug wires are connected properly? The TPS will undergo fuel cut when decelerating but it could occur if the TPS is faulty. Have you measured the voltage at the ECU that relates to the TPS ( Green/Red wire pin 2G) to verify that the ECU is getting the correct signal. Does the car rev properly when in neutral. Are you sure the primary injectors are working properly? Does the car run better w/the trailing coil disconnected or the same. If you disconnect the TPS and remove the vacuum hose to the Boost Sensor and cap the vacuum line does the car respond the very same or not?