VW tune-up spec lookup
VW Tune-Up Spec LookupEvery number for the job, keyed to the code.
Pick the engine code off the case and the distributor that is actually in it: Type 1 upright, Type 3 or Type 4 Bus. You get valve lash, points gap, dwell, timing and the hose position it is set with, plugs, idle and oil, then every part for the job off our shelf in one cart. Where the sources disagree, we show you the disagreement instead of picking for you.
The tool
Pick the code. Get the numbers.
Timing goes with the distributor, not just the engine. A 1971 engine wearing a 009 does not time like a 1971 engine, and copying the factory figure onto the wrong distributor is how people cook a head.
The letters before the serial. Not sure?
Count the vacuum hoses on the can. Type 1 uprights only.
All high-zinc for flat-tappet cams.
Pick an engine code. The tool needs JavaScript; the reference table further down does not.
The order
Do it in this order, every time.
Each step moves the one after it. Set them out of order and you chase your tail.
- Valves first, dead cold.Overnight cold, not "it's been sitting an hour." Every other adjustment depends on the valve gap, and an air-cooled head grows as it heats.
- Points gap, then dwell.Gap with a feeler gauge on the high point of the rubbing block, then confirm with a dwell meter. Changing the gap moves the timing, so this comes before timing.
- Timing, warm, at idle.Engine at temperature, idle in range, vacuum hoses exactly as the result says. Hose on or hose off changes the reading by ten degrees or more on some distributors.
- Idle speed and mixture last.Then check the timing at idle once more. Fan belt: about half an inch of deflection under thumb pressure, midway between the pulleys.
Still runs rough?
Test compression next.
If the valves, points, plugs and timing are all on spec and it still idles rough, stop throwing parts at it. Ten minutes with a compression gauge tells you whether the engine itself is healthy.
- Warm the engine, then pull all four plugs.Warm, because that is how VW's figures were measured. All four out, so the starter spins it at the same speed for every cylinder.
- Disable the ignition, open the throttle.Pull the coil wire from the cap and ground it. Hold the throttle wide open so every cylinder breathes freely.
- Crank each cylinder the same number of times.Five or six compression strokes, until the needle stops climbing. Write the number down, release the gauge, move on.
- Compare against the spec and against each other.VW's manual gives 114–142 psi new and 100 minimum for the B and early AE 1600, and 107–135 new and 85 minimum for later AE, AH and AK engines, with no more than 28 psi between cylinders. Your figure, where one exists, is in the result above.
- One low cylinder? Do a wet test.Squirt about a teaspoon of engine oil into that cylinder and test again. If the number rises, the rings are worn. If it doesn't, it's a valve or the head seal. On an air-cooled VW, check for a tight valve first: adjust the valves and test again before you condemn the head.
Compression figures: VW Workshop Manual, engine volume, as reproduced in the type2.com technical library. The wet-test reading is from Rob and Dave's VW Resource. VW's figures cover the later 1600 codes only; we found no factory figure for the 1200, 1300 or 1500 and won't borrow one.
Reference
Every code, in one table.
Timing as the factory set it with the original distributor. Plugged means the vacuum hose off and the carb port plugged; connected means hoses on, strobe at idle.
| Code | Engine | Years and vehicle | Timing | Set with | Dwell | Sources |
|---|---|---|---|---|---|---|
| Type 1 upright · Beetle, Ghia, Thing, and Bus to 1971 | ||||||
| No letter, to 3.93M | 1200, the 36 horse | c. 1955 to Jul 1960 · Beetle, Ghia | 7.5° BTDC | Static | 50° | BusTopia |
| No letter, 5.0M to 9.73M; D | 1200, the 40 horse | Aug 1960 to Jul 1965 bare serials; D from Aug 1965 · Beetle, Ghia, Bus | 10° BTDC | Static, or strobe at 800–950 rpm with the vacuum hose plugged | 50° | Volks Conversions, Old Volks Home, BusTopia |
| G | 1500 Bus | 1964 to Jul 1965 · Bus | 10° BTDC | Static, or strobe at 800–950 rpm with the vacuum hose plugged | — | Volks Conversions, BusTopia |
| F | 1300 single port | 1966 USA; 1966–70 elsewhere · Beetle, Ghia | 7.5° BTDC | Static, or strobe at 800–950 rpm | 42°–58° | Volks Conversions, BusTopia |
| H | 1500 single port | 1967 USA Beetle; 1966–67 Bus · Beetle, Ghia, Bus | 7.5° BTDC | Static, or strobe at 800–950 rpm | 42°–58° | Volks Conversions, BusTopia |
| H5 (and H, 1968–69) | 1500 single port, M157 emissions | 1968–69 · Beetle, Ghia | 0° TDC | Strobe at 800–950 rpm, vacuum hose off and plugged | 42°–58° | Volks Conversions, Old Volks Home |
| B, B5, B6 | 1600 single port | 1970 Beetle, Ghia; 1968–70 Bus | 0° TDC | Strobe at 800–950 rpm, vacuum hose off and plugged | 47°–53° | Volks Conversions, BusTopia |
| AD, AE | 1600 dual port | 1971–73 Beetle, Ghia; 1971 Bus | 5° ATDC | Strobe at 800–950 rpm, both vacuum hoses connected | 44°–50° | Volks Conversions, BusTopia, VW Resource |
| AH, AK | 1600 dual port | 1973–74 · Beetle, Ghia, Thing | 5° ATDC | Strobe at 800–950 rpm, both hoses connected, two-hose distributor 043 905 205C | 44°–50° | Volks Conversions, VW Resource |
| AJ | 1600 dual port, fuel injected | 1975–79 · Beetle, Super Beetle, Convertible | 5° ATDC | Strobe at idle, vacuum hoses connected | 44°–50° | Volks Conversions |
| E, L, AB, AC, AF, AR, AS, AG, AL, AM | Rest-of-world and low-compression codes | Europe, Mexico, Brazil and other markets | By distributor | The tables we checked carry no separate figure for these codes | — | None found |
| Type 3 · Notchback, Fastback, Squareback | ||||||
| Type 3, no letter (1961–63) | 1500 carbureted | 1961–63 · Notchback, Variant, Type 34 Ghia | 10° BTDC | Static, or strobe at 800–950 rpm with the vacuum hose plugged | — | Old Volks Home |
| R, K, M, N, P, T (to 1967) | 1500 and 1600 carbureted | 1964–67 · Notchback, Fastback, Variant, Type 34 Ghia | 10° BTDC | Static, or strobe at 800–950 rpm with the vacuum hose plugged | — | Old Volks Home |
| K, M, N, P, T (1968 on) | 1500 and 1600 carbureted, after 1967 | 1968–73 · outside the US | By distributor | We found no published figure for these carbureted export engines | — | None found |
| U (1968–71) | 1600 fuel injected, D-Jetronic | 1968–71 · Fastback, Squareback, Notchback | 0° TDC | Static, or strobe at 800–950 rpm with the vacuum hose off and plugged | — | Old Volks Home |
| U, U5, X (1972–73) | 1600 fuel injected, D-Jetronic | 1972–73 · Fastback, Squareback | 5° BTDC | Strobe at 800–950 rpm with both vacuum hoses off and plugged. Reset idle afterwards | — | Old Volks Home |
| Type 4 · Bus 1972–79 | ||||||
| CB (1972) | 1700 Type 4, dual carb | 1972 · Bus, US and Canada | 5° ATDC | Strobe at 800–950 rpm, vacuum hoses connected | 44°–50° | Old Volks Home |
| CB, CD (1973) | 1700 Type 4, dual carb | 1973 · Bus, US and Canada | 10° ATDC | Manual (CB). Automatic (CD): 5° ATDC. Strobe at 800–950 rpm, vacuum hoses connected | 44°–50° | Old Volks Home |
| CB, CD, AW (1974) | 1700 and 1800 Type 4, dual carb | 1974 · Bus, US | 10° ATDC | Manual. Automatic: 5° ATDC. Strobe at 800–950 rpm, vacuum hoses connected | 44°–50° | Old Volks Home |
| ED; GD to mid-1976 | 1800 and 2000 Type 4, fuel injected | 1974 California, 1975, 1976 to chassis 226 2077 584 · Bus | 5° ATDC | Strobe at idle, vacuum hoses connected | 44°–50° | Old Volks Home, Bentley |
| GD from mid-1976; GE | 2000 Type 4, fuel injected | Mid-1976 to 1979 (49-state 1979) · Bus | 7.5° BTDC | Strobe at idle, vacuum hoses connected | 44°–50° | Old Volks Home, Bentley, Ratwell |
| GE (1979 California) | 2000 Type 4, fuel injected, Hall ignition | 1979 California · Bus | 5° ATDC | Strobe at idle, vacuum hoses connected | Not applicable | Old Volks Home, Bentley |
| CA, CE, AP, CJ | Type 4, export dual carb | 1972–79 · Bus outside the US | By distributor | We found no published figure for the export carbureted engines | 44°–50° | None found |
Wide table, scroll it sideways on a phone
Sources: VW and Bentley factory tune-up tables as reproduced by Bentley Publishers; Volks Conversions timing figures for the original distributor; The Old Volks Home distributor specification list; Bentley's 1975–79 fuel-injected Bus tune-up table and Ratwell's Bentley errata and hydraulic lifter notes (Type 4); JBugs Bosch tune-up parts tables; BusTopia tune-up chart; Rob and Dave's VW Resource timing and valve notes; the VW fan-shroud valve decal. Dwell figures come from a single chart and are labelled that way in every result.
Questions
The things people ask us.
0.004" or 0.006" on the valves?
My 1971–74 runs badly at 5° after TDC. Is the spec wrong?
The light says one thing at idle, the book says static. Which is right?
How solid are the Type 3 and Type 4 numbers?
Why does the cart leave some items unchecked?
Talk to a person
Read us the number off the distributor.
If the engine still will not idle right after a by-the-book tune-up, that is worth a phone call. Have the car in front of you and the Bosch number off the distributor body. We would rather spend ten minutes on the phone than have you chase a timing figure that was never right for your distributor.