Rattaan

Well, here goes. I have a '90 NA, the auxiliary ports were stuck, so I took apart the intake to fix them. After removing the lower intake manifold, I found I was without 6-port sleeves . I went out to the junk yard Monday, and raped and pillaged some sleeves from another RX, brought them home cleaned the snot out of them as well as the sleeve holes in the housings, installed them and put the intake manifold back together. I made sure, taking my time, that everything was reconnected properly and old/bad vac lines(only a few left since rebuilt) were replaced. All electronic connectors are connected. All hoses.. etc. etc. Ok. I then jumper the two wire connector to prime the fuel pump, and turned the key to the on position about 8 seconds. I then tried to start it. I then realized I still had the wire jumper in place, so I removed it and tried again. No start, but heard one big pop while trying. Checked all connections again, all hoses, all electrics, all fine. Decided that spraying carb cleaner in the intake may have caused it to flood or foul the plugs. Pulled the plugs out, cleaned some crud and fuel off of them, reinstalled them and tried again. Nothing. Pulled plugs again, disconnected CAS, turned the motor over a few times with the pedal floored to evacuate any leftover crud/fuel/oil, reconnected them, tried again, nothing. Hooked up a timing light, connected to leading plug 1. Sparks fine. leading plug 2, again fine(of course, duh). Connected to trailing 1. Nothing. Trailing 2, nothing. Rechecked electrical connections, all fine. Tested resistance of CAS, fine. Tested resistance of trailing coils, fine. Reconnected everything again, and tried turning it over with the trailing plugs out. They sparked, somewhat weakly but sparked just the same. Put them back in. Nothing. While the trailing plugs were out, and I was cranking the motor, there were a few small backfire sounds(this is the closest it's been to sounding like it's trying to start). Completely reset the timing with the CAS. Tried again, failure. When I crank it over it doesn't seem to do anything but spin the motor. What should I be checking next? I was thinking of pulling the trailing plugs trying to get them to spark outside and see if the timing light is picking them up. Beyond this, I don't know. Is there a way to check if the ignitor is bad? Should I even try to check that? Is there some other trick or obvious thing I am overlooking here? Please help if you can, I'm loosing my mind here

Aaron Cake

iTrader: (1)

Forget the trailings for now, the car will start and run without them.

Have you tried adding oil or (shudder) ATF to the engine to unflood and allow it to build compression? Carb cleaner will strip all oil from the rotor housings can cause an artifical loss in compression.

Rattaan

Well, I'll give it a try with some oil. How much should I use? Also, are the trailing side plugs the first to start the combustion process or is it the leading? I thought the leading fired constantly(or pretty much constantly). Or am I completely wrong? Should I try using starting fluid or something like that too?

Sniper_X

1st) Its probably flooded.

The S5 cars have a routine in the firmware that kills the injectors if you hold the pedal to the floor, and crank it.
do this for about 10 seconds.

Then, stry to start it normally.

You might not have luck right away.
Just know that if you release the pedal from the floor AT ALL while cranking, it will start the injectors.

Pressing it BACK to the floor will not kill the injectors again, the ECU must see the throttle WIDE OPEN and stay there for the flood routine to kick in.

You can use this behavior to try starting at WOT, then reduce the pedal to half and then full to see if it will start.

If it starts to lumber, then keep cranking.

(Just dont burn your cables.)


2ND) Trouble on the horizon...
I saw NO MENTION of you replacing the hardedned vaccum hoses that you remove to clean the intake.

Hopefully you did and just never mentioned it.

If you didn't, your potentially screwed.
It may never idle properly until you do.

Yousee the looseness that you felt when replacing the old hoses, is bad enough that each one has a tiny vac leak.

Collectively, you lose so much vaccum, that you cant idle or run strong any more.

I have seen this a thousand times, and each time the hardened hoses weren't replaced, the car ran poorly until they were.

3rd)
You should have had your injectors cleaned while you were in there. Also, re-using the hard rubber seals on the injectors is a very bad idea.

4th)
Intake gaskets. Did you rip or crack one?) replace it.

The vaccum on rotaries at high RPM (the kind of RPM that your ports use) is MASSIVE. it will leak.

I have done this job that you have done more times than I can count. I have this one nailed.

As i do with many S5 projects.
So if you have questions, feel free to ask me!

Rattaan

Thanks for the reply sniper. The vac hoses currently being used are in very good shape, I made sure of that I don't have any hardened lines at all. The injectors should be fine, since I had the intake off only a couple months ago and cleaned everything while doing a port matching job. All gaskets were also in top shape. I think I tried the WOT method already as well, but what the heck, it can't hurt to try again right? I'll go out and give all this a try in the morning and get back to you on it. Thanks again for the help, if I can't get anywhere I might PM you guys if that's alright?