Could my fuel pre-heater be leaking into my fuel line?

[muleears]

I found out the other day (on this forum, BTW ) that it was my fuel pre-heater that was leaking fuel. About the same time the car started acting up. In the morning, about 2-3 min. after starting in would begin to misfire badly. One morning it was so bad it stalled several times and would only hold about 2K RPM's at full throttle. Eventually it cleared up and ran smoothly. Could my fuel pre-heater have been: 1. Leaking air into the fuel line causing the dismal performance? or 2. Leaking coolant into the fuel line and possibly ruining my IP? or 3. Leaking off enough fuel pressure to cause the poor performance? My main concern is the IP. I know running coolant through it will kill it. As far as I know I am on my original IP. I have since bypassed the pre-heater (while I search for another one) and my leak has stopped and so has the poor running problem. At least the last two days. What could be going on? I know the experts will have some answers!

[muleears]

Got any ideas?

By your sig I presume that this is your 87?

If the there was coolant I believe that the level would be going down since the coolant expands as the engine warms and the IP is drawing in anything it can. In the past 10 months I have learned the there are many places for fuel lines to leak on a W210. I would be curious if your car can run on an incline. I had a leak this past summer. The car was parked on a slight incline and then stalled after two munutes. There was a leak at the highest point of the fuel system before the IP.

Just some thought at the moment.

[PatricdeBoer]

I would vote for airleaks. Back when I was puttering around with a fuel heater for for wvo on my 300d I could have sworn that my heat exchanger was leaking into the fuel. It turned out to be sucking air.