Buick is showing classic symptoms of vapor lock

  • Article by: PAUL BRAND
  • Updated: March 1, 2014 - 12:48 PM

Q: Here is a problem that I have fought for almost two years. My 2001 Buick Regal will not start after a shutdown and heat soak. The car has 128,000 miles, never shuts down while driving, starts and runs perfectly in the morning. When it won’t restart, you can crank it until the battery runs down but the car won’t start. After shutting the engine off it will start immediately — if you don’t wait too long! Engine operating temperature is normal, it never overheats and has a new thermostat and ECT sensor. There are no intake manifold leaks, either vacuum or coolant. Fuel pressure is normal but a new regulator was installed along with a new MAF sensor. In a no-start condition the spark will jump a gap of at least one inch at the coil.

In the summer I carry a jug of water in the trunk (in winter I use snow) and in a no-start condition I pour about a quart of water on the intake plenum. The car will start right away and will run perfectly until the next no-start condition.

A: I can’t recall a better description of vapor lock. The proper term is fuel percolation, which describes residual engine heat boiling the ready fuel supply in the fuel rails near the plenum/intake manifold. When this occurs, fuel pressure fades due to the aerated fuel disrupting fuel delivery from the injectors. Even though fuel pressure may be “normal” when tested with the engine running, I suspect fuel pressure drops quickly after shutdown due to percolation.

Using water to cool the intake stops the percolation. The first few injector pulses bleed air from the rail and, as fuel pressure returns, the engine starts.

But how to eliminate the problem? Start with three simple steps. Idle the engine for 30 seconds before shutdown to allow coolant to carry residual combustion heat from the cylinder heads into the radiator. Pop the hood open to the safety catch position to allow hot air to escape from under the hood. And try different brands of fuel, looking for a fuel with a vapor pressure less prone to this issue.

In addition, make sure airflow through the A/C condenser and radiator is clear and unobstructed. If the cooling system hasn’t been serviced recently a power flush may lower coolant and underhood temperatures measurably.

And to cover all the bases turn the ignition to the “on” position and listen for the fuel pump to run for two seconds and then stop, confirming that the fuel pump relay and fuel pump are operating properly. I’d also test for injector pulse widths from the PCM to confirm that the fuel injectors are being commanded to open/close on a hot restart.

Q: I have a well maintained 2003 Acura 3.2L TL-S model with 114,000 miles. My Goodyear dealer has continued to propose replacement of the timing belt and water pump. He said the belt should have been replaced at the seven-year mark or 100,000 miles. I can’t seem to find any definitive recommendations from Acura or on the Internet about this repair. I want to maintain the car and continue to drive it for a number of years and would value your opinion on this repair.

A: Acura’s service recommendation for this vehicle and engine, as outlined in my ALLDATA automotive database, calls for timing belt replacement at 105,000 miles/84 months under normal operating conditions. Under severe service conditions — operation at ambient temperatures under minus-20 degrees or above 110 — replacement is recommended every 60,000 miles.

With this engine, a timing belt failure could allow contact between pistons and valves, resulting in catastrophic engine failure, so a new timing belt makes perfect sense. Include pre-emptive replacement of the water pump.

  • get related content delivered to your inbox

  • manage my email subscriptions

ADVERTISEMENT

Toronto - LP: D. Hutchison 2 FINAL
NY Yankees - WP: M. Tanaka 5
Washington - WP: S. Strasburg 2 FINAL
Miami - LP: N. Eovaldi 1
NY Mets - WP: J. deGrom 10 FINAL
Atlanta - LP: E. Santana 2
Boston - WP: J. Kelly 3 FINAL
Baltimore - LP: M. Gonzalez 2
Milwaukee - LP: W. Peralta 0 FINAL
Pittsburgh - WP: V. Worley 1
Chicago WSox - WP: J. Danks 10 FINAL
Tampa Bay - LP: N. Karns 5
Cleveland - WP: C. Kluber 7 FINAL
Minnesota - LP: A. Swarzak 2
Detroit - LP: R. Porcello 2 FINAL
Kansas City - WP: J. Guthrie 5
Seattle - LP: H. Iwakuma 3 FINAL
Houston - WP: C. McHugh 8
Los Angeles - WP: C. Perez 8 FINAL
Chicago Cubs - LP: J. Turner 5
Texas - WP: S. Tolleson 2 FINAL
LA Angels - LP: H. Street 1
Philadelphia - LP: M. Gonzalez 6 FINAL
Oakland - WP: S. Doolittle 8
San Francisco - LP: R. Vogelsong 2 FINAL
San Diego - WP: I. Kennedy 8
Arizona - LP: W. Miley 3 FINAL
Colorado - WP: C. Bergman 8
Cincinnati - WP: A. Simon 7 FINAL
St. Louis - LP: L. Lynn 2
San Diego 22 FINAL
Buffalo 10
Dallas 34 FINAL
St. Louis 31
Washington 34 FINAL
Philadelphia 37
Houston 17 FINAL
NY Giants 30
Minnesota 9 FINAL
New Orleans 20
Tennessee 7 FINAL
Cincinnati 33
Baltimore 23 FINAL
Cleveland 21
Green Bay 7 FINAL
Detroit 19
Indianapolis 44 FINAL
Jacksonville 17
Oakland 9 FINAL
New England 16
San Francisco 14 FINAL
Arizona 23
Denver 20 FINAL
Seattle 26
Kansas City 34 FINAL
Miami 15
Pittsburgh 37 FINAL
Carolina 19
Chicago 9/22/14 7:30 PM
NY Jets
NY Giants 9/25/14 7:25 PM
Washington
Columbus 4 FINAL
Carolina 3
Buffalo 0 FINAL
Washington 1
St. Louis 3 FINAL
Columbus 4
Calgary 1 FINAL
Edmonton 3
Edmonton 0 FINAL
Calgary 1
Old Dominion 45 FINAL
Rice 42
Troy 0 FINAL
(12) Georgia 66
Georgia Tech 27 FINAL
Virginia Tech 24
Eastern Mich 14 FINAL
(9) Michigan State 73
Iowa 24 FINAL
Pittsburgh 20
Bowling Green 17 FINAL
(19) Wisconsin 68
Maryland 34 FINAL
Syracuse 20
Tulane 13 FINAL
Duke 47
Hawaii 12 FINAL
Colorado 21
Marshall 48 FINAL
Akron 17
North Carolina 41 FINAL
(23) East Carolina 70
Army 21 FINAL
Wake Forest 24
Virginia 33 FINAL
(20) BYU 41
(6) Texas A&M 58 FINAL
SMU 6
Rutgers 31 FINAL
Navy 24
Central Mich 10 FINAL
Kansas 24
Utah 26 FINAL
Michigan 10
Florida 21 FINAL
(3) Alabama 42
Louisville 34 FINAL
FIU 3
Fla Atlantic 19 FINAL
Wyoming 20
Indiana 31 FINAL
Missouri 27
San Jose St 7 FINAL
Minnesota 24
Texas State 35 FINAL
Illinois 42
Massachusetts 7 FINAL
Penn State 48
Georgia State 14 FINAL
Washington 45
Appalachian St 20 FINAL
Southern Miss 21
(14) Miss State 34 FINAL
(17) LSU 29
Northern Ill 14 FINAL
Arkansas 52
Middle Tennessee 17 FINAL
Memphis 36
Utah State 14 FINAL
Arkansas State 21
Miami-Ohio 24 FINAL
Cincinnati 31
Idaho 24 FINAL
Ohio U 36
Ball State 23 FINAL
Toledo 34
(13) So Carolina 48 FINAL
Vanderbilt 34
(4) Oklahoma 45 FINAL
West Virginia 33
Ga Southern 28 FINAL
South Alabama 6
UNLV 14 FINAL
Houston 47
Miami-Florida 31 FINAL
(21) Nebraska 41
New Mexico 38 FINAL
New Mexico St 35
Clemson 17 FINAL
(1) Florida State 23
California 45 FINAL
Arizona 49
San Diego St 7 FINAL
Oregon State 28
(2) Oregon 38 FINAL
Washington St 31
Louisiana 9 FINAL
Boise State 34
Texas Tech 9/25/14 6:30 PM
(24) Oklahoma State
Appalachian St 9/25/14 6:30 PM
Ga Southern
(11) UCLA 9/25/14 9:00 PM
(15) Arizona State
Middle Tennessee 9/26/14 7:00 PM
Old Dominion
Fresno State 9/26/14 7:00 PM
New Mexico
Texas-El Paso 9/27/14 11:00 AM
(25) Kansas State
Tennessee 9/27/14 11:00 AM
(12) Georgia
Vanderbilt 9/27/14 11:00 AM
Kentucky
Wyoming 9/27/14 11:00 AM
(9) Michigan State
Northwestern 9/27/14 11:00 AM
Penn State
TCU 9/27/14 11:00 AM
SMU
Iowa 9/27/14 11:00 AM
Purdue
Tulane 9/27/14 11:00 AM
Rutgers
So Florida 9/27/14 11:00 AM
(19) Wisconsin
Colorado State 9/27/14 11:30 AM
Boston College
Western Mich 9/27/14 11:30 AM
Virginia Tech
Maryland 9/27/14 12:30 PM
Indiana
Akron 9/27/14 12:30 PM
Pittsburgh
Bowling Green 9/27/14 2:00 PM
Massachusetts
Arkansas 9/27/14 2:30 PM
(6) Texas A&M
Kent State 9/27/14 2:30 PM
Virginia
Western Ky 9/27/14 2:30 PM
Navy
Minnesota 9/27/14 2:30 PM
Michigan
Wake Forest 9/27/14 2:30 PM
Louisville
FIU 9/27/14 2:30 PM
UAB
(1) Florida State 9/27/14 2:30 PM
NC State
Miami-Ohio 9/27/14 2:30 PM
Buffalo
Colorado 9/27/14 3:00 PM
California
Louisiana Tech 9/27/14 3:00 PM
(5) Auburn
Texas 9/27/14 3:00 PM
Kansas
Temple 9/27/14 3:00 PM
Connecticut
(16) Stanford 9/27/14 3:15 PM
Washington
TX-San Antonio 9/27/14 4:00 PM
Fla Atlantic
South Alabama 9/27/14 4:00 PM
Idaho
Cincinnati 9/27/14 5:00 PM
(22) Ohio State
Rice 9/27/14 6:00 PM
Southern Miss
Missouri 9/27/14 6:00 PM
(13) So Carolina
Boise State 9/27/14 6:00 PM
Air Force
North Carolina 9/27/14 6:00 PM
Clemson
Central Mich 9/27/14 6:00 PM
Toledo
Troy 9/27/14 6:00 PM
ULM
New Mexico St 9/27/14 6:30 PM
(17) LSU
Memphis 9/27/14 6:30 PM
(10) Ole Miss
Duke 9/27/14 6:30 PM
Miami-Florida
Texas State 9/27/14 7:00 PM
Tulsa
Washington St 9/27/14 7:00 PM
Utah
(8) Notre Dame 9/27/14 7:00 PM
Syracuse
(7) Baylor 9/27/14 7:00 PM
Iowa State
UNLV 9/27/14 7:00 PM
San Diego St
Illinois 9/27/14 8:00 PM
(21) Nebraska
Oregon State 9/27/14 9:30 PM
(18) USC
Nevada 9/27/14 9:30 PM
San Jose St
Chivas USA 0 FINAL
Toronto FC 3
Toronto 40 FINAL
Brt Columbia 23
Edmonton 23 FINAL
Hamilton 25
Calgary 15 FINAL
Montreal 31
Ottawa 32 FINAL
Saskatchewan 35
Connect with twitterConnect with facebookConnect with Google+Connect with PinterestConnect with PinterestConnect with RssfeedConnect with email newsletters

ADVERTISEMENT

ADVERTISEMENT

ADVERTISEMENT

 
Close