Honda Civic/Acura Integra

since 1994 of release

Repair and car operation

Diagnostics of a condition of the engine with use of the vacuum gage

Unfortunately, results of the indications removed by means of the vacuum gage are easily wrong for interpreting, and therefore, they should be analyzed together with the data received during performance of other diagnostic checks.

When reading indications of the indicator of the vacuum gage it is necessary to pay attention not only to absolute size of a deviation of an arrow, but also for speed of its moving. The majority of measuring instruments of import production show depth of depression in inches of a mercury column. Thus it is necessary to consider that all standard requirements are provided for a case of performance of checks at zero height above sea level. Relief increase on each 300 m after a mark of 600 m leads to understating of instrument readings approximately on 25 mm.

Connect the vacuum gage directly to the inlet pipeline – not to the throttle case. Track, that during check performance all hoses remained connected, - otherwise it will be impossible to consider the read instrument authentic.

Before starting measurements, warm up the engine to normal working temperature. Prop up wheels protivootkatny boots and cock the parking brake. Transfer transmission to the situation "R", start the engine and leave its working at turns of normal idling.

Before engine start attentively check fan blades on existence of cracks and other damages. Try not to approach to a krylchatka of a hand and a measuring instrument. Also avoid to take a position directly ahead of the car!

Consider vacuum gage indications. On the average depth of depression in the inlet pipeline of the serviceable engine should be rather stable (without arrow breakthroughs) and to make near 432÷560 mm of mercury. In below-mentioned paragraphs the scheme of interpretation of removed indications is given:

1. Low stability of indications can be the certificate of leaks through laying between the inlet pipeline and a head of cylinders, or between the pipeline and the throttle case. The probability of violation of tightness of a vacuum hose, failure (towards backlog) the ignition moment, or violation of installation of phases of a gazoraspredeleniye is not excluded also. Check installation of a corner of an advancing of ignition by means of a stroboscope, then serially exclude all other possible causes, carrying out the checks listed in the present Chapter, after it it is meaningful to uncover GRM drive for the purpose of check of correctness of combination of adjusting labels.
2. If the result of measurement appears on 76÷203 mm of mercury. lower norms and thus take place fluctuations, violation of tightness of laying of the inlet pipeline near the inlet port, or malfunction of an injector of injection of fuel can appear the reason of such deviation.
3. Regular deviation of an arrow of a measuring instrument down from the stable indication on 51÷102 mm of mercury. with high degree of probability testifies to leakages of valves. Check kompressionny pressure in cylinders.

5. Frequent vibration of an arrow of the indicator within a range in 102 mm of mercury. at single turns of the engine, being accompanied smoke emission from an exhaust pipe, speaks about wear of directing plugs of valves. If the arrow starts to vibrate at increase of turns of the engine, check on existence of signs of leakages of laying of the inlet pipeline and a head of cylinders. Estimate degree of a prosedaniye of klapanny springs, check on existence of traces прогара valves and try to reveal ignition admissions.

7. In the presence of fluctuations of an arrow of a measuring instrument in a wide range check kompressionny pressure or carry out the test for leaks for the purpose of identification of the defective cylinder or violation of tightness of laying of a head of cylinders.
8. If the arrow of a measuring instrument with slow speed "walks" in a wide range of a scale, check passableness of PCV system and structure of a mix of idling, also make sure of absence of leaks through laying of the carburetor/case of a throttle and the inlet pipeline.
9. Estimate speed of return of indications of the vacuum gage to a reference value when closing butterfly valve after lifting of frequency of rotation of the engine to size about 2500 rpm at the expense of a fast priotkryvaniye of a zaslonka. The indication at first should fall practically to zero, then rise over value, characteristic for normal turns of idling approximately by 130 mm of mercury. and again to return to the indication of single turns. If depth of depression is restored slowly and does not form a peak throw at sharp closing of a butterfly valve, it is necessary to check, whether piston rings are worn-out. At a long delay of return of indications check passableness of system of production of the fulfilled gases (often appear the exhaust silencer or the catalytic converter are blocked) – it is simplest to disconnect simply suspected section of system of release and to repeat check.