Cold cranking is hard start

[longrowe]

Hello. I have a 1998 C2 ROW TIP Coupe. Just lately (past week or so) my car is taking a while to fire up. Like 5-6 seconds whereas it used to start almost instantly. This is only on the first cold start (morning or having sat at work all day). Once it starts, if I turn the key off and re-start, it fires up immediately. Sitting at a gas station, fires up immediately. Only when it sits for a long period will it have a long cranking time.

 

I hooked up the durametric and there is only one fault, in the transmission, P0740 "Solenoid valve torque converter clutch". The car only has about 50,000 miles but everything on the engine/drivetrain seems original. I cannot see in the history where the coils had been changed. I had a major service done when I purchased it since there was a significant gap in the maintenance history. That was 1500 miles ago and the plugs were changed at that time along with the other "major service" items.

 

Other than the hard cold start, it runs flawlessly. Any idea where to start looking? Could it be the fuel pump even though a re-start is no problem?

[JFP in PA]

Hello. I have a 1998 C2 ROW TIP Coupe. Just lately (past week or so) my car is taking a while to fire up. Like 5-6 seconds whereas it used to start almost instantly. This is only on the first cold start (morning or having sat at work all day). Once it starts, if I turn the key off and re-start, it fires up immediately. Sitting at a gas station, fires up immediately. Only when it sits for a long period will it have a long cranking time.

 

I hooked up the durametric and there is only one fault, in the transmission, P0740 "Solenoid valve torque converter clutch". The car only has about 50,000 miles but everything on the engine/drivetrain seems original. I cannot see in the history where the coils had been changed. I had a major service done when I purchased it since there was a significant gap in the maintenance history. That was 1500 miles ago and the plugs were changed at that time along with the other "major service" items.

 

Other than the hard cold start, it runs flawlessly. Any idea where to start looking? Could it be the fuel pump even though a re-start is no problem?

 

It could be the fuel system bleeding down pressure while it is sitting for longer periods.  Try hooking up a fuel pressure test gauge to the fuel rail and see if the pressure is bleeding off while it sits.

[longrowe]

I have ordered a fuel pressure tester. Unfortunately, tool stores are not that prevalent in Bahrain so it will be a week or so to arrive. I did jumper the fuel relay and the fuel pump does spin up, so that is encouraging. If the pressure is bleeding off, does that mean a fuel pump replacement or is there a check valve elsewhere in the system?

[JFP in PA]

I have ordered a fuel pressure tester. Unfortunately, tool stores are not that prevalent in Bahrain so it will be a week or so to arrive. I did jumper the fuel relay and the fuel pump does spin up, so that is encouraging. If the pressure is bleeding off, does that mean a fuel pump replacement or is there a check valve elsewhere in the system?

 

Some of the early cars had a fuel pressure regulator (red arrow on the left) on the fuel rail, which can be the source of the problem, or you could have one injector that is leaking down.

 

[White987S]

Make sure you have a spare DME relay. This is a weak spot in the 993s. Classic sign is, the car will crank, but not fire. Yours may be on the way out.

[longrowe]

Luckily my car is a 996 not a 993. But I will keep that in mind. I noticed when you turn the key, the fuel pump does pulse momentarily. So this morning I turned the key on then off a couple times before starting. The car started normally. So my guess is that the fuel pressure is bleeding off. Now to check to see if it is the fuel pump or the regulator.

[longrowe]

Replaced the fuel pump. Car starts up perfectly again.