There is no full moon or dog-days heat to explain it, but a new mania is sweeping Capitol Hill - a fevered rush to promote synthetic fuels.

As gasoline lines grow longer and political frustration builds, members of Congress are trampling on each other in the hurry-up drive for synfuels.

House and Senate legislative hoppers are brimming with bills - at least 40 so far - to stimulate synthetics, and the fun really has only begun. Take yesterday, for example:

A House Education and Labor subcommittee, ordinarily devoted to social concerns, ignored jurisdictional lines and cranked out the whopper of the lot - a $205 billion program to produce synfuels.

The Senate Energy Committee held an unusual 7 a.m. session to take up a multibillion-dollar synthetics proposal sponsored by chairman Henry Jackson (D-Wash.), Majority Leader Robert C. Byrd (D-W.Va.), and 18 others. Quick passage has been promised.

House leaders prepared to get a $2 billion synthetics bill, geared to producing enough petroleum to meet military needs, to the floor next week. That neasure, pushed by Rep. William S. Moorhead (D-Pa.), is likely to be broadened if it gets through the Rules Committee today, as is expected.

A Senate Banking subcommittee, meanwhile, heard three prominent Washingtonians, including former Navy secretary Paul R. Ignatius, call for a crash federal program to get a synfuel program going.

As Ignatius, Eugene M. Zuckert and attorney Lloyd N. Cutler put it, synfuel seems to be an idea whose time has come after bobbing about for years in the congressional backwaters.

The problem has not been the technology for converting coal, oil shale, tar sands, grain or garbage into synthetic petroleum and gas. The know-how has been around for years.

The problem has been that as long as petroleum prices and supplies remained reasonably stable, the high and subsidized cost of synfuels had little appeal. Hopelessly splintered congressional jurisdictional abetted the action.

Jurisdictions on Capitol Hill remain splintered, but the price and supply picture has changed. It has put new pressure on Congress to do something - "even if it is the wrong thing," as Sen. Dale Bumpers (D-Ark.) capsulized it the other day.

"They are really serious about it this time," said Carter Manasco, a former Alabama congressman who now lobbies the Hill for the National Coal Association. "The gasoline lines and the fear that prices are going to $2 a gallon have a lot to do with it."

The frontrunner in the legislative derby appears to be the Moorhead bill, which House leaders agreed to push passage before Congress goes home for the July 4 holiday.

Rep. Toby Moffett (D-Conn.), after a Tuesday leadership meeting on the Moorhead defense-production bill, said, "The synthetic fuel thing is greased. You've never seen such a locomotive."

If Moorhead is riding a locomotive, the bill that rushed through the House employment-opportunities subcommittee yesterday looked like a crack express weaving through a crowded switching yard.

The bill is the brainchild of Rep. Carl D. Perkins, chairman of the Education and Labor Committee, whose coal-rich eastern Kentucky district stands to gain from a synfuel program.

Perkins said that he and his two dozen cosponsors, frustrated that the administration and Congress have not provided leadership, decided to act on their own, even though critics might be quick to say Education and Labor is the wrong forum.

The bill would authorize a quasi-governmental corporation to issue $200 billion in bonds and spend up to $5 billion more in tax money to get a full-scale synthetic fuel program going.

Again yesterday, the jurisdictional confusion that long has plagued Congress on energy matters was underscored. A major synfuels bill introduced last week by Rep. John D. Dingell (D-Mich.) was referred to eight House committies. The Perkins bill, however, touches on matters ordinarily handled by 11 other committees.

Energy and synfuels at Educational and Labor? Perkins made it legislatively proper by simply adding his proposal as a title to a small manpower training bill.

Before the Perkins express left the station yesterday, with a unanimous vote, subcommittee Chairman Augustus F. Hawkins (D-Calif.) wondered if anyone else wanted to make "a historic statement."

Indeed, chuckled Baltasar Corrada, the delegate from Puerto Rico. He had a "historic" question. Is Puerto Rico eligible to participate in the synfuel plan?

Absolutely, said Perkins. He promised that his full committee will adopt the bill next week.