'75 1911cc L-jet daily driver (when rain is not predicted)

My heat works so I have been driving to work for several weeks now. Probably drive the 914 70% of the time. Work is 25 minutes away. I hop on the interstate and cruise about 65 or 70.

Today on the way home I noticed I had gotten up to about 80 heading up a small hill. As I do on hills, I checked my VDO CHT, but today the temp was going down. It normally runs a hair below 350.

I felt a sudden power loss, kinda like a big wind hit me, As I tried to coast down the off ramp the engine died quickly. It restated easily, but I had to do the ole big toe brake and the little toe gas to keep it idling.

It spit and sputtered all the way home and the CHT gauge stayed at 250. It smelled alot different as I pulled into the garage. Maybe rich.

The CHT sensor is a ring under the plug of cylinder 3, so I guess I will start by pulling that plug.

This is my 1st real problem in 2 good driving years and about 20K miles.
Any other thoughts???

Clark

Well, I let it cool down and bit and I attempted a restart. It seemed to want to hold the idle now, but I noticed that the fuel light was on. Did not notice that before. I added 2 gallons of non-ethanol that I had for my mower.

She started and idled. I let it run for a while and watched the CHT. it made it to 300 and I shut her down.

Was it all low fuel related? How does that have anything to do with the CHT on #3?

for help.... anyone have ideas?

dirty fuel filter?

Easiest way to determine if it was fuel related, drive straight to the closest gas station and top off your tank. You said you added 2 gallons at home, so filling up to the top will reveal just how low you got.

Both comments sound reasonable for the spitting and sputtering. Although I hate the thought of trying to get to the fuel filter.

Would a low fuel or fuel pressure situation cut the fuel to #3 and cause it to cool down 100 degrees? Again, this is standard L-Jet set up.

Vacuum Leaks?

L-Jet hates Vacuum issues...

you could be dealing with multiple issues at once..

1. fuel delivery issue do to vacuum leaks and/or clogged fuel filter
2. failure of the thermostat which in turn controls your cooling.

I would check for vacuum leaks and check fuel pressure just before the injectors. Additionally make sure the cooling shrouds are working correctly once the thermostat opens.

my 2 cents... good luck

Thanks for the thoughts...

I have an in-line pressure gauge in the fuel ring. Unfortunately, since the car would not idle when I got home, I could not get out and look at it. But during the later test, I noticed that the Fuel PSI was 35-40 while the car was idling. That is normally the reading.

I understand that the flaps are for pre-heating.... basically re-directing the cooling air away from the oil cooler and cylinder fins to help the engine warm up faster. If my flaps have created a 100 degree drop, I might have a million dollar design.

If you have never gone to this site, check it out. He builds and re-builds our t-stats and has some good info about them.

AwesomePowderCoat.com T-stat FYI

Tim, The tank took 10 more gallons. 12 total. 23.8 mpg about avg. So maybe not a low fuel issue. I am wondering now if there is something in the tank. Maybe it blocked the sock. Plus it is on the sender. Topped the tank but only get 3/4 on the gauge.

Car ran perfectly to and from the station. But the vdo CHT showed 300. 30 to 50 degrees lower than usual.

I think you were running dangerously low on fuel. This explains the loss of power and cooler operating temps. Ethanol fuels are hygroscopic and our tanks are openly vented, it's possible the last few cups of fuel in the tank had water present. It's all speculation at this point.

Well I like that explaination the best. Beats having a junk problem in the tank. And explains why i did not see a pressure problem.

I try to buy pure gas. More often than not tho, i get e-10. IIRC that tank was E10. I guess when I don't, I should add some "gas-dry"? Plus i should fill up sooner.

I had no clue Ethanol was hygroscopic, that is good to know. In the north east during winter months we get a blend of fuel that has a ton more Ethanol in it.