SVT Zetec engine hard to start

[Steve Stephens]

Since pretty much finishing my build on my Superlight 7 with stock SVT Zetec, the engine has been very hard to start. When I first hit the starter it will roar to life but then immediately die. Then is seems to try at times to start but only for a second or I can crank away with no hint of firing. This has been a problem from the first time I tried to start the engine which was new from Caterham USA when I bought it.

Once I have it started it will run rather loudly and labored for a few minutes and then settles and quiets down and runs well. I don't know if this is lack of fuel or the plugs are getting fouled. How can I tell if the fuel pump is giving the engine fuel or if it's not pumping right?

I have my BAR check on Tuesday but the starting issue has occurred every time when I have tried to start the car from cold. I think it has also occured sometimes when sitting for a short time and cooling off some.

Edit: I pulled the spark plugs and they are all wet which is how I found them the first time I tried to start the engine months ago. Blew off the plugs with compressed air and heated them with a torch some. Replaced and the engine won't even try to fire. Could the spark not be hot enough to make it fire a wet plug? I thought fuel injected engines were very reliable and easy to start all the time and that has been my experience with my regular cars.
Thanks,
Steve

[magnusfeuer]

Sounds like an ignition issue. If not that, you are running way rich.

I assume that you run the stock ECU and have stock injectors. If you also have a stock fuel rail and pressure regulator, the amount of fuel going into the engine should be what the ECU wants injected there.

A number of questions:

Do you have the right type of spark plugs?

If you remove a spark plug and ground it against the engine while cranking, do you see a clear spark? Watch out for electrical shocks and fire from the gas in the cylinder that is now open to the atmosphere.

If you plugin an diagnostic monitor to the OBD-II port (assuming that it is in wiring harness), do you see any error codes? The engine may be in limp home mode due to incorrectly wired or faulty sensors.

In the OBD-II channels, if available, does the TPS (Throttle Position Sensor) report a value that matches your throttle input. It should go from 0-100% or 0-90 deg. If the ECU things you are running an open throttle when you are not, you will run very rich.

In the OBD-II channels when it runs, what does the MAF (Mass Air Flow) report. It should be (if I remember correctly) less than one oz/sec while idling. I can get a better value if this seems to be an issue. If the engine things you are sucking in a lot of air when you are not, you will run very rich.

That's the things from the top of my head. I am sure that the rest of the mechanics on the site will reply with better suggestions.

/Magnus F.

[Doug Liedblad]

A stock Zetec with stock ECU will show several codes and you'll have to sort thru them to find the ones relevant.

My first ECU (PCM from Ford) was defective and would fire all the injectors when switched on.

I found this out by removing the fuel rails with the injectors attached. When switched on they all shot a stream of fuel. A new ECU fixed the problem.

Hard starting could be low fuel pressure too. It should be around 43 psi for the stock Zetec. I think the SVT is the same. Less than 40 is a problem. There should be a schrader valve on the fuel rail for testing and pressure relief.

I had a hard starting issue on my SVT engine because of bad connection to the +12 V on the coil pack. The center terminal I believe.

I sent you a PM with my phone number, give me a call when you can.

Doug

[athens7]

The SVT engine includes an ignition immobilizer that is usually disarmed by the diode inside the ignition key. On the Seven, the diode is shrink wrapped to the immobilizer antenna, which will not fit around the Caterham ignition cylinder (no diode in the ignition key). My car had an intermittent no start/stumble/die, which was cured by shielding the part of the harness that split from the group coming up through the transmission tunnel that connected to the immobilizer, using aluminum foil. Do NOT wrap the immobilizer antenna, as the car will not start under any circumstances. I also relocated the immobilizer antenna, which was wire tied close to the ignition switch, to the bulkhead at the steering column. Since this was done-starts every time. This may have nothing to do with your problem, but, if you turn the car off and then back on every time you try to start it, the fuel pump will prime each time, leading to too much fuel in the rail, and perhaps elsewhere. Try moving the immobilizer antenna around under the dash as you try to start the car. I can probably provide pictures if this appears to be the problem. There is no insulation, and a lot of electrical stuff, under the Caterham scuttle, so interference is a possibilty.

[Steve Stephens]

Thank you Magnus, Doug, and athens 7. I think that's a good start. I spoke at length with Doug tonight and, hopefully, can try some things tomorrow or gather some more information for you all. It's nice to know there are a bunch of other Caterham owners out there to get some help from and I need it now as I have no knowledge of computer controlled cars and fuel injection.
Steve

[Roll a 7]

You have just experienced the Caterham dealer network.

[magnusfeuer]

The unpaid Caterham 7 dealer network, mind you.

/Magnus F.

[athens7]

Actually, I have paid (sometimes dearly) for every bit of knowledge I have about my car, and I have the receipts to prove it :rolleyes:! How about the
"paid-in" dealer network?

[mopho]

My car does the same thing. If it sits overnight, it usually takes a few tries to get it started and then it is fine.

[magnusfeuer]

Morgan,

That's probably a crappy cold start map. I can fix that if I can get my hands on the car when it is cold.

/Magnus F.

[rzempel]

That's probably a crappy cold start map. I can fix that if I can get my hands on the car when it is cold.

So...how can I entice you to help me sort out my (non)starting issues? :-)

Randall

[Doug Liedblad]

Try offering him the membership fee.

And lots of it.

[magnusfeuer]

Rzempel's original cold start thread resurrected.

/Magnus F.

[mopho]

Try offering him the membership fee.

And lots of it.

Diapers seem to work too

[soareyes]

Diapers seem to work too

New ones are preferred, as I'm sure he has plenty of used ones already ;)