DRIVEABILITY Concerns Related To Fuel Volatility (F013/96)
Publication date: 1996-05-24Reference number: F013/96
DRIVEABILITY CONCERNS RELATED TO FUEL VOLATILITY
TECHNICAL SERVICE BULLETIN
Reference Number(s): CAT. F, NO. 013/96, Date of Issue:
May 24, 1996
DRIVEABILITY CONCERNS RELATED TO FUEL VOLATILITY
Model(s): All Mazda Models
Category: F - Fuel & Emission Control Systems
Bulletin No.: 013/96
Date: May 24, 1996
DESCRIPTION
Some driveability concerns are related to fuel volatility. This bulletin briefly describes some of the symptoms and causes.
SYMPTOM
- Unleaded gasoline with volatility too high for ambient temperatures may cause the following concerns during warmed-up driving and hot restarts:
- No Start
- Rough Idle
- Surging
- Vapor LockNOTE: These symptoms are most typical during spring and summer months when winter gasoline may still be available.
- Unleaded gasoline with volatility too low for ambient temperatures may cause the following concerns:
- Long Crank Time
- Rough Idle
- Hesitation
- Poor Throttle Response
- Induction Backfire
- Stalls
- Similar symptoms caused by lean operation during initial cold starts and drive-away.
NOTE:
Gasoline's volatility is higher (vaporizes easily) in the winter and lower in the summer.
REPAIR PROCEDURE
- Verify the concern.
- Perform the diagnostics in section F of the workshop manual.NOTE: Often, no trouble codes are found if the concern(s) are caused by gasoline.
- If the concern(s) is still present, the fuel volatility may be the cause.
WARM ENGINE - WARM/HOT AMBIENT TEMPERATURES
- Recommend that the customer try to identify a source of fresh, good quality gasoline. A station which receives frequent shipments of fuel will likely be a source of fresh, good quality gasoline.
- Using such gasoline may be more appropriate for these ambient temperatures.
COLD ENGINE - COLD AMBIENT TEMPERATURES
- Advise customers using a higher than recommended octane to switch to the recommendations in the owners manual.
- Do not advise using a higher octane than recommended for that engine. Premium octane grade unleaded gasoline does not provide better fuel economy or performance than regular octane grade gasoline. Only advise using a higher octane grade gasoline to avoid potentially damaging "spark knock" or "ping". Recommend this octane only after diagnostic procedures are ineffective.
- Advise customers using the recommended octane grade unleaded gasoline to try another brand.
- If customers are using a gasoline containing an oxygenate, advise them to try another brand of oxygenated gasoline. If possible, advise customers in this category to try a gasoline which is not oxygenated.
NOTE:
The oxygenate type should be posted on the pumps.
GENERAL INFORMATION
- No fuel additives will resolve this concern(s).
- Always use a gasoline with a "In-tank System Deposit Control" detergent that helps maintain proper operation of fuel injectors and keeps valves clean.
- This information may be used on any model year vehicles exhibiting these concerns.