What the hell is wrong with this car?

I just replaced the coils with a known good set. I have fuel and the car slowly cranks it's way to a start (every 5th attempt) after about 30 seconds of continuous cranking. It finally started and I drove it around, the car was pretty peppy, but my car needs high revs, due to the port job it has very little low end but tons of upper..

The car just idled fine after it started but the damn thing wont consitantly start. Also I timed it perfectly but when the car is at idle there is no spark signal.. I restabbed the CAS like 5 times and it is right on the money.

Why would the car have so much trouble starting..? Also the Check engine light is on but not flashing. Also does that vac line on the end of the 2ndary fuel rail have anthing to do with starting? mine is capped off...

 

I dont think that vac line on the secondary fuel rail has to do with starting, but it needs to be connected to the manifold (we are talking about the fuel pressure regulator right?

 

I'm assuming it's a fresh rebuild?

Could be the battery/charging system. Hook it up via jumper cables to a running car, then try to start it. If it fires right up, there ya go.

 

The rebuild is freshish.... But not fresh. I have driven it around before. Also I had a standalone on it when I bought it. I removed it and put the car back to OEM. The car was running a Jacobs Ignition pack... Could it be that It needed that additional spark to start?

 

Ok another question:

i am running the car as an N/A right now, It has a very aggressive port job. The car is using T2 injectors (550cc) I wonder if the spark isn't stong enough to start the car under normal conditions.. And the extra fuel is not having the chance to ignite. In thoery flooding itself out. The car is S5 so when I push down on the gas the car defloods itself then attempts to start. It doesn't quite start without the 3 minute cranking.. But it will attempt to start then flood out...

So can I assume that I NEED the ignition pack to start the car.. Once it starts it gets good spark and drives like normal... Any ideas?

 

Is it using 550s all the way around? Do you have anything to tune it with? S-AFC, Rtek or anything? It sounds like its just flooding out. The 550s all around would be my guess as the culprit. Try putting good stock injectors in it or get something to tune those 550s down. Or try putting a good ole fuel pump cut off switch

 

I would have to agree. put the 460cc primaries back in and try starting it again. give the battery a good charge too.

 

Well no, I am without a piggyback at this time. I may try swaping out the primaries. Would a coil booster (like my jacobs rotary pro) on the primary coil help the starting?

 

1. why do you have the vac line on the secondary fuel rail capped?
you know that's your fuel pressure regulator right?

-this will result in your car running static fuel pressure all the time. for example, with the fuel press reg capped off, your fuel pressure is the same as it would be if you were at full throttle. the fuel pressure regulator is there to pull the fuel pressure down when there is vacuum on the motor, the vacuum pulls the fuel pressure down (or raise it too when/if it sees boost) via the vac/boost source. and you have it capped of... hook it up!

2. why are you using TII 550cc injectors in an NA?
which ecu are you using? NA or TII? i'm assuming NA since you said you put it back to stock form or whatever.

-do you think the stock ECU knows the difference between 460cc and 550cc injectors? no. so that means its shooting the same pulsewidth that it would need to run the car with 460cc injectors through 550cc injectors, making the engine get way too much fuel.

3. with no fuel pressure regulator and 90cc's too much fuel i'm surprised it starts at all...

-its a good thing you're driving it NA. if you'd been driving it around turbo and boosting, you'd have blown your engine on the first few pulls because it didnt having rising fuel pressure in boost!

all that being said, put the 460cc injectors back in it while its NA and on the stock ecu. and hook up the dang fuel pressure regulator. sheesh.

 

possibly, but thats overkill.

i bet it will start fine with a fuel pressure regulator. it will just run a little rich from still having oversized injectors.

ALSO, i believe that the stock FC ecu's shoot all 4 injectors during cranking (i could be wrong about this, but i'm pretty sure) so if you're goign to the trouble of swapping out the primaries, swap out the secondaries too.

 

^ what he said.

 

Ok I swapped out the primaries to 460cc injectors (the only 2 I had) The car still refuses to start. I hooked up the fuel rail to a vacuum nipple on the LIM. The ECu is a T2 ecu...

The car tries even less to start now.

 

FC's only fire primaries when cranking. Below a certain rpm they fire a fixed MS of fuel, above cranking RPMs the amount of fuel injected is dependent on the Coolant temp sensor. Check for intake leaks also. Intake leaks (injector seals etc) can cause lean condition (no start).

 

I went through and made sure everything was tight. The car just acts like it has no spark untill the engine really gets spinning. This is very frusterating. What the hell else coud it be?

 

my car is stock and does the same thing every two months or so?

 

this may be a long shot but. maybe the motors new. so it hasent built up full compression yet.

 

even on the first crank of the engine a fresh rebuild should have atleast 90psi of compression on both rotors unless totally shitty parts were used.


RRTEC, i did not know you had a TII ecu. so you have an S5 TII ECU and S5 TII engine that you're running NA for the time being? use the TII primary injectors.
i bet with the correct injectors and a functioning FPR it will start up just fine.

i thought you were running an NA ECU.

 

Where should the FPR hook up to as far as vacuum? I have it hooked to a random vac nipple on the LIM (N/A Lim)

I was running the 550cc's as the primaries and 2ndaries, now it has 460cc injectors in the primaries and 550cc's in the secondaries.

But I already had the setup you are suggesting and it wouldn't start. I wonder if the FPR is bad?

As far as the s5 harness goes I have the long runners going to the 2ndaries and the short runners from each injector plug starnd going to the primaries.....

Uggg...

 

Remidial post but I couldent tell. The coloent sensor is confirmed to be in working order right? Mine had the same cranking problem and after a few days of witch hunting that was the problem.

AF

 

Are you talking about the sensor on the back of the water pump housing? If so I don't know.. If it helps the temp guage doesn't work..... Hmmm....

 

Local Guys- if someone will come over and help me out I have a really nice S5 Turbo (low miles) and a exhaust manifold you can have, if you come get this thing running with me...

 

Damnit, why are you so far away? I would have totally no clue what to do, but I would still come try for that deal.

 

Mine's hooked up to some random vacuum source. As long as they're vacuum, I'm pretty sure they're all the same.

Attached is the coolant temp sensor.

 

How fast does it crank? Trying to start it for 3 minutes at a time isn't good. You can screw the starter and drain the battery.

No spark signal as in no tach? The tach signal comes from the trailing coils. Make sure those are working fine.

Pull the codes from the computer.

Are you talking about the nipple attached to the mushroom looking thing? Kind of looks like the PD, just positioned vertical? On an S4 N/A that's the FPR.

I just looked up the S5, it's not vertical apparently.

I'm not an authority on S5 turbo's (vvvvveeeerrrrrrry far from it), this is just what I've noticed in the FSM.

 

Well the tach bounces on cranking, and I was getting spark... The timing light was showing no spark but I accidently had it on the trailing coil (doh) so that was my bad... Some folks are saying to buy a new thermosensor and that might fix it.. but....