Dream Theater

to make a long story short... My FC3s ( Turbo II ) doesnt start when I turn the key to crank it. It just chuggs away and eventually floods. That's issue number 1. Does anyone know why this may be happening? I've gotten it to start here and there by pulling the Fuel Relay under the steering column but obviously this should not be a standard way of starting the car. Also i've checked all the vacum lines on my car and when it does start it just dies...Refuses to hold idle. Any ideas???

-Dustin-

edvenoy001

i just had the exact same problem,it was my pulsate dampener on the pressure side of the fuel rail,i replaced that all probs solved

trochoid

iTrader: (6)

This is usually an indication of leaking injectors. Send them out for cleaning and calibration.

nukeall

yes chumm or buy new ones ..... it happened to me i broke one of my injectors and it was sick flooding......changed my PD with a bajo bolt ....and its perfect ... just my idle is a little high

Carzy Driver

sounds like it's time to do a compression check.

nukeall

are you saying me ???? compression check ??? dude my idle is rough becuz of my tps i need a new one...and a fuel filter too ...

HAILERS

Hard to start engines can be a number of things. The compression like mentioned above is one. Remember a series four turbo engine has a lower compression ratio than the n/a's and later turbo engines.

Attached is a graph that shows what happens when you start a S4. Notice the AFM is out of the picture. The water thermo sensor........rpm.........and the START SIGNAL coming to the ECU from the start circuit are the players. There is a START FUEL MAP that determines how much fuel the thing gets during STARTING.

What could be and probably is the problem with a older engine, is that the mixture is too rich during the start cycle for the low compression your engine might have. One way to overcome this is to depin the pin 3B from the ECU. Now the ECU will NOT use the preset mixture amount on the Start map but use the AFM.

How much difference? WIth 3B the injectors might stay open as much a 30ms while if 3B is disconnected, the amount will be approx 6ms duration.

Make sense? Yes. The only problem with doing this is during cold weather, and I don't mean very cold. Somewhere around under 65 degrees the mixture will be too lean and make cold starts difficult BUT once the water temp rises, the starts will be good the rest of the day. I'm talking water temps of approx 65 degrees.

There's ways around this problem also. You can buy a Universal Vlotage Switch as at this site: http://www1.jaycar.com.au/productRes...p?FORM=KEYWORD and have the trigger set so the pin 3B is active for temps under say 120 degrees so there will be no cold start problems.

In the thread creators case, you might just make a Fuel Cut Switch as mentioned thousands of times on this Forum. Just search and use the words FUEL CUT SWITCH and for a name NZCONVERTIBLE.

The JPG:

Another not much mentioned item is the Water thermo Sensor. If it goes bad (rare as hens teeth), the ECU defaults to a value of 176 degrees as a default temp. So what, you say. Well if you look at the jpg that is attached you see that the Start Fuel Map depends on the water thermo sensor. If the engine is stone cold, then the amount of fuel being injected will be not enough and will make for a difficult start as you can easily see.

To check a water thermo sensor is kids play. Put a meter on the green/white wire at the ECU (pin 2I from menory) and turn the key to ON. The voltage when stone cold will be approx 2-3 vdc. Warn the engine up fully and it should gradually drop to approx .4 to .5 vdc when the water is hot. If it does that then there's not a damn thing wrong with it.

In your case just make the fuel cut switch THEN think about how to do other methods.

I also attach two jpg of a Palm showing in the lower LEFT hand corner the pulse width of the injectors WITH the 3B connected and the other WITHOUT 3B connected. See the difference???? Large.