Archive for the ‘ Engine ’ Category

Weber Carburetors TYPE 26 IMB1 & 26 IMB3

by Miller | June 7, 2009 | In Engine No Comments

The following Weber carburetor types have been fitted:

  • New 500 ——————— 26 IMB 1
  • 500 Sport ——————– 26 IMB 3
  • 500D————————– 26 IMB 4
  • Station Wagon ————- 26 OC
  • 500F ————————– 26 IMB 6
  • 500L ————————– 26 IMB 10 (incorporates CO limiter for idling)

The weber 26 IMBl carburetor is a downdraft, single body carburetor with 1.0236” (26 mm) diameter throat at the height of throttle shaft.

The fuel mixture rating system consists of a throttle valve controlled by accelerator pedal through a cable which operates a lever secured to throttle valve shaft. This carburetor is fitted with a progressive-action starting device which enables the driver to suit the mixture richness to the most varied conditions of starting, until the engine has reached the rated operation temperature.

The dampened needle valve ensures a smooth engine running since, thanks to its dampening device, it is not affected by vibrations and, therefore, keeps steadily constant the level in carburetor bowl.

Operation.

weber carburetor diagram

Diagrammatic section of Weber 26 IMB1 carburetor

1. air corrector jet 2. air inlet 3. idle speed mixture duct 4. idle speed jet holder 5. idle speed air orifice 6. filter cover 7. Filter 8. fuel inlet connection 9. needle valve seat 10. Needle 11. float pivot 12. Float 13. idle speed jet 14. main jet holder 15. main jet 16. Bowl 17. idle speed mixture adjustment screw 18. idle speed mixture orifice 19. Throttle 20. transition hole 21. primary Venturi (not interchangeable) 22. emulsion orifices 23. emulsion well 24. secondary Venturi (not interchangeable) 25. main nozzle

Referring to the diagram. the air from above, [More]

Engine Stalls

by Miller | February 27, 2009 | In Troubleshoot Engine No Comments

ENGINE TROUBLE DIAGNOSIS AND CORRECTIONS#2

If The Engine Stalls.

POSSIBLE CAUSES

REMEDIES
1) ldling speed too low  1) Increase throttle opening slightly and adjust mixture rating as recommended under «Carburetor» .
2) ldle mixture too lean or too rich  2) Adjust mixture rating as recommended under «Carburetor» .
3) Carburetor flooding:

  • a) due to too long starting with inserting choke without using accelerator;
  • b) due to carburetor defect.

 

 

 3) Proceed as follows:

  • a) remove and wipe spark plugs or wait some minutes and start engine with choke out and all open throttle;
  • b) remove and rebuild carburetor as recommended in covering chapter.
4) Needle valve in carburetor stuck.  4) Rebuild as recommended under «Carburetor».
5) dirt or water in fuel line or carburetor.  5) Remove and thoroughly clean carburetor; if trouble  recurs, flush and blow fuel tank and lines.
6) Incorrect fuel level in carburetor bowl.  6) Check and adjust fuel level as recommended under «Carburetor» .
7) Incorrect use of choke device.  7) Operate as recommended in covering paragraph of chapter «Carburetor» .
8) Loose or corroded battery terminals  8) Clean terminals and tighten nuts as recommended under <<Battery>>. Replace cable and terminal clamps if they are too much worn.
9) Loose ignition cables from coil to distributor and from distributor to spark plugs. 9) Examine and re-set circuit. 
10) Loose ignition switch connection. 10)  Examine and re-set circuit.
11) Spark plugs dirty, damp or gaps set too wide. 11) Clean spark plugs and set gap as recommended under <<Spark Plugs>>.

12) Distributor breaker contact points dirty, oxidized or blackend; pitted points or excessive point gap. 12) Clean contacts and adjust point gap as recommended under “Ignition Distributor”
13) Distributor rotor contact worn. 13) Replace distributor rotor.
14) Distributor advance not operating.  14) Rebuild ignition distributor as recommended in covering chapter.
15) Defective coil and condenser.   15) Inspect and replace both of them, if necessary. Operate as recommended under “Ignition Coil” and “Ignition Distributor”
16) Exhaust system restricted.  16) Thoroughly clean exhaust silencer, exhaust piping and manifolds.
17) Incorrect valve tappet clearance.  17) Adjust tappet clearance as recommended under “Timing Gear”.
18) Burned valves. 18) Replace valves.
19) Poor Compression.    19) Check compression (99.6″ to 106.7 p.s.i. - 7 to 7,5 kg/cm2 , Model 500 and 106.7 to 113.8 p.s.i. - 7,5 to 8 kg/cm2, Model 500 Sports, using a pressure gauge; rebuild engine if compression is too low.
20) Engine overheating. 20) Check generator and fan drive belt for a loose condition and the air outlet control thermostat on engine cowling for defective operation; proceed as required, following recommendations under “Cooling”

Engine Will Not Start

by Miller | October 16, 2008 | In Troubleshoot Engine No Comments

 

ENGINE TROUBLE DIAGNOSIS AND CORRECTIONS#1

Engine Will Not Start.

 

POSSIBLE   CAUSES

REMEDIES 
1) Weak battery. 1) Check and re-charge battery as recommended under «Battery».
2) Corroded or loose battery terminal connections.  2) Clean, examine and tighten cable clamps to  battery terminals, as recommended under « Battery ». Replace cables and clamps if they  are too  much  corroded.
3) Weak coil. 3) Check coil and replace by a new one.
4) Loose or broken ignition cables from coil to distributor and from distributor to spark plugs. 4) Examine and re-set circuit or replace faulty cables.
5) Cracked distributor cap. 5) Replace cap.
6) Moisture or dirt deposits on distributor cap contact points. 6) Wipe and clean points.
7) Distributor breaker contact points dirty, oxidized or blackened; pitted points or excessive point gap. 7) Clean contacts   and   adjust point gap as recommended under « Ignition Distributor ».
8) Distributor rotor cracked, or showing signs of burning or wet. 8) Clean or replace rotor, if necessary.
9) Center distributor cap contact worn or broken or with distorted pressure spring. 9) Replace contact and contact spring.
10) Shorted condenser or with poor insulation. 10) Bench test condenser and replace it, if defective.
11) Fouled spark plugs or excessive spark plug gap. 11) Clean  spark plugs and  set gap as recommended  under «Spark Plugs».
12) Improper timing (ignition). 12) Check and set timing as recommended under « Ignition Timing ».
13) Defective starting motor. 13) Locate failure and correct as recommended under « Starting   Motor”. 
14) Carburetor flooded:a) due to too long starting with inserted choke without using  accelerator;b) due to carburetor defect. 14) Proceed as follows:      a) remove  and wipe   spark   plugs or  wait   some minutes and start engine with choke out and all open throttle;      b) remove and rebuild carburetor.
 
15) Dirt or water in fuel line or carburetor. 15) Remove and thoroughly clean carburetor; if trouble recurs, flush and blow fuel tank and lines.
16) Incorrect fuel level in carburetor bowl. 16) Check fuel  level in  bowl and adjust it, if necessary,  as recommended under  « Carburetor».
17) Defective fuel pump. 17) Remove and rebuild fuel pump as recommended under  <<Fuel Pump>>
18) Poor compression.  18) Check compression (99.6 to 106.7 p.s.i. - 7 to 7,5     kg/cm2, Model «500» and 106.7 to 113.8 - 7,5 to 8 kg/cm2, Model « 500 Sports »), using a pressure gauge; service valve seats and rebuild engine if compression is too low.
19) Engine overheating. 19) Check generator and fan drive belt tension and air outlet shutter control thermostat operation. If faults are as out­lined under « Cooling », follow directions in this chapter to remove them.

Identifying Your Fiat & Engine

by Miller | October 11, 2008 | In 500 Workshop, Engine 12 Comments

HERE YOU WILL LEARN WHERE AND HOW TO IDENTIFY YOUR FIAT 500 MODEL, ENGINE, CHASSIS, COLOR & PARTS ORDERING NUMBER.


Numerous models of the FIAT 500 have been produced over more than a decade. There are, therefore, many different models which have been developed considerably from the first.


Below is you Fiat 500 Identification plate, to understand how it reads i have broken it down for you. [More]

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