fuel leak, 6.2L, can't find it anywhere

[dabney]

Hello, this is my first post. I have owned a 1983 Chevrolet C20 6.2L Suburban since it was brand new. I have taken the best care of it as I know how. I have faithfully changed the oil every 2500 to 3000 miles. I have used the best oils available, now using Rotella 15/40. Anyway, I had the compression of all 8 cylinders checked the other day, and all of them were in the 410 to 430 PSI range. My problem is, for about 2 months, I have noticed a small fuel leak at the front mounting bracket bolt on to the engine area of the starter motor. It is next to the round flywheel sheet metal cover, and some of the fuel drips through the hole in the bottom of the round cover. It is also apparent right where the front end of the starter motor mount and the engine meet. I have crawled all over the engine, from taking the air cleaner off, searching the "valley", looking carefully at the injection pump, the fuel pump, the injectors and their lines, the injector "return" rubber lines, the end caps on both rear injectors, the outside of the engine, top to bottom, along the sides, and the lines to and from the fuel filters, the fuel tank, in fact every place around the engine compartment. It is dry. All of the places I have mentioned are dry. The only place it is moist is where I mentioned earlier, i.e. next to the starter motor, and the round cover over the flywheel. I am at a loss. It is not leaking gallons, quarts, or pints. Just a little, and it quits soon after when I have turned the engine off. As I said, the valley is dry, no sign of recent fuel. Does anyone have any ideas where it might be coming from, and should I do anything about it? Is it a rather minor thing? The motor has about 200,700 miles on it and "runs like a sewing maching" as my Dad used to say. Any advise, help, or suggestions will be greatly appreciated!

[john8662]

Most likely the fuel leak is on the fuel return circuit.

There are rubber fuel return lines that run from injector to injector. On the ends of the circuits (on the rear cylinders #7&8) there is an end cap. Most likely it's a ruptured end cap and the fuel is running down the side of the block down the starter and down the transmission inspection cover.

[dabney]

Hello John, I have checked with my hand both sides injector end caps. They are dry. That was a problem I did have several years ago. It was found very soon afterwards. Any other suggestions? dabney

[BobND]

On many 6.2's, the "valley" drains though a hole at the back, right into the flywheel housing.

Some versions (manual tranny, later model, or perhaps, replacement engine) have a bent steel tube that inserts into the hole at the back of the valley, and carries any drainage out through a hole drilled on the left side in the engine bellhousing flange.

It seems as your's doesn't have the tube, and fuel leakage into the valley is entering the flywheel housing, and dripping out the bottom cover.

You may have a leaky hose, or filter, or a IP throttle shaft seal leak, a hydraulic head-to-case leak, or a leak in the IP's advance piston area.

The leak may be only at highway speeds, or at idle, or while shutdown, and, by the time you look at it, the valley has dried up.

I would take a very close look for leaks in those areas.

Stuff a paper towel under the IP for a while, and see if it becomes fuel-soaked.