Okay, new post same issue.
Car will occassionaly start. Will not stay running.
I have spark and set timing.
I replaced entire fuel system including tank and correct injectors and fuel pump and filters. I have fuel pressure.
I have checked added and cleaned grounds including adding new ones at computer.
I have tried a few known good computers and afm and map sensors.
I have checked compression. It is 122 in all faces.
I have tried 2 different upper intake manifolds.
I have set and tried and tested 2 different tps sensors.
I'm stumped.
Any ideas?
Are you sure they are the correct injectors? It's not difficult to mix up high impedance injectors with low impedance computer.
Yep. I have center tabs which I believe are correct for an s4 with the resistor pack.
In reply to wvumtnbkr:
BE SURE. I grabbed a resistor pack out of an '88 parts car.
Check injector impedance - roughly 2 ohm is 86-87.5, roughly 12-14ohm is 87.5 and up. N326 is the low impedance computer, N327 is high impedance.
This is probably not your problem but any time you play musical parts you need to watch.
How long does it stay running when it does start? It could be the afm not turning on the fuel pump.. The pump runs when cranking, but if the afm doesn't trip it, it'll die about two seconds after you stop cranking.
If this sounds plausible, then there's a black connector between the drivers side shock tower and firewall that runs the fuel pump when shorted.
This issue drove me nuts after installing a rebuilt engine one time. I must have damaged the afm while it was out.
Sounds like real healthy compressions. The suggestions above have potential. A few more ideas for you:
Why is it hard to start and why doesn't it stay running? Is it because the spark plugs are getting wet/fouled? Is it not running due to flooding?
This is the most common issue for me when I first get a rotary going. Good Luck
WonkoTheSane wrote:
How long does it stay running when it does start? It could be the afm not turning on the fuel pump.. The pump runs when cranking, but if the afm doesn't trip it, it'll die about two seconds after you stop cranking.
If this sounds plausible, then there's a black connector between the drivers side shock tower and firewall that runs the fuel pump when shorted.
This issue drove me nuts after installing a rebuilt engine one time. I must have damaged the afm while it was out.
I have that connector wired up with a switch.
It does not run properly when it starts. It seems either crazy lean or crazy rich.
I will read the plugs today and see if they have any color to them.
Okay, I pretty much got it solved.... finally!
The air flow meter tested out electronically just fine. I did not remove it from the airbox.....
....until today.
The flapper door is stuck. I used a different one after testing it....
Car starts and stays running!
Now I just need to adjust timing and the throttle position sensor.
Suite!
Awesome! Thanks for the update :)
hmmm... That didn't exactly fix it.
Now, I can get the car to start by fiddling with the idle and the idle mixture screw and maybe the timing. Then, once running I set everything where it should be according to the FSM.
Once it cools down (say a few hours later) it is difficult to start again.
any ideas?
Thanks!
Rob R.
Coolant temperature sensor good? I was surprised at just how much fuel I had to throw into the cold engine when I was tuning the Haltech. Might be running too lean on startup.
