VAZ 2107 — a legend of the Soviet automobile industry, but even she sometimes refuses to start. If your “Seven” is silent when you turn the key or sneezes but does not start, do not rush to call a tow truck. In 80% of cases, the problem is solved on its own in 10–30 minutes - you just need to know where to look.
This article is not abstract “check your spark plugs” advice, but step-by-step analysis taking into account features VAZ 2107 (both carburetor and injection modifications). We will analyze the symptoms “from simple to complex”: from a dead battery to distributor malfunctions, and also tell you why, after replacing the timing belt, the “seven” may stop starting even with a working starter. All recommendations are valid for models 1982–2012.
1. Diagnostics by sounds: what does your VAZ 2107?
The first thing to do is listen to the car. The nature of the “silence” or sounds when trying to start will tell you in which direction to dig:
- 🔇 Absolute silence when you turn the key, there is a power problem (battery, ignition switch, fuses).
- 🔊 Relay clicks, but the starter does not turn - the battery is discharged or the terminals are oxidized.
- 🔄 The starter turns, but the engine does not catch - problems with fuel, ignition or compression.
- 💥 Sharp pops in the muffler - over-enriched mixture (flooded spark plugs) or faulty valves.
If the starter cranks slowly crankshaft, but the engine does not start, either is to blame battery (voltage below 11.5 V), or starter (brushes or bearings are worn out). On VAZ 2107 It might also work with an injector. immobilizer — check the flashing light on the panel.
2. Battery: The first reason everyone misses
On VAZ 2107 (especially with a carburetor) the battery often becomes the “weak link”. Moreover, the problem is not always in the discharge - sometimes the culprits are:
- 🔋 Oxidized terminals - clean them with sandpaper and lubricate them
Lithol. - 🔌 Poor ground contact — check the wire from the negative terminal to the body (often oxidizes under the bolt).
- 🔄 Sulfation of plates - if the battery is more than 5 years old, it may not produce the required current even after charging.
How to check? Turn on the headlights: if they glow dimly or go out when you try to start, the battery is low. On injection VAZ 2107 If the voltage is low, the ECU (electronic control unit) may block starting.
⚠️ Attention: If after “lighting up” the engine starts, but after 5–10 minutes it stalls and will not start again, the problem is generator, not in the battery. Check the belt and diode bridge!
☑️ Emergency battery check
3. Starter: why does it turn idle or not react?
On VAZ 2107 The starter is one of the most vulnerable points. Typical faults:
| Symptom | Probable Cause | How to fix |
|---|---|---|
| Starter does not respond to key | Defective retractor relay or ignition switch | Ring the relay, check the lock contacts |
| The flywheel turns but does not engage | Worn bendix or flywheel crown | Replace bendix or flywheel |
| Grinding noise on startup | Bendix slipping or flywheel teeth broken | Disassemble the starter and inspect the gears |
On carburetor VAZ 2107 The starter often “dies” due to moisture (condensation) entering the housing. If after washing or rain the car stops starting, remove the starter, dry it and lubricate it. WD-40.
Advice: If the starter turns, but the engine does not start, try lightly tapping the starter housing with a hammer (not too hard!). Sometimes this helps to “revive” jammed brushes.
Before removing the starter, disconnect the negative terminal of the battery - this will protect you from a short circuit and clear ECU errors (on injection models).
4. Ignition system: spark plugs, coil and distributor
If the starter turns vigorously, but the engine does not catch, the ignition is to blame. On VAZ 2107 check:
- Spark plugs — unscrew and inspect:
- 🔥 Dry - no fuel supply.
- 💧 Wet — fills with gasoline (the problem is in the carburetor or injector).
- 🖤 Black soot - rich mixture or coil malfunction.
On injection models, instead of a distributor there is ignition module. If it fails, the engine will “trouble” or not start at all. Check error codes (eg P0300 - random misfires).
⚠️ Attention: If after replacing the timing belt VAZ 2107 stopped starting, check the camshaft and crankshaft marks! Broken valve timing is a common mistake when doing DIY repairs.
How to check a spark without special equipment?
Unscrew the spark plug, insert it into the tip of the high-voltage wire and attach it to ground (for example, to the valve cover). Ask an assistant to turn the starter - if the spark is blue and stable, the ignition system is working.
5. Fuel system: carburetor vs injector
Here are the ways VAZ 2107 There are differences with the carburetor and injector. Let's consider both options:
Carburetor (models before 2006)
Typical problems:
- 🚫 The jets are clogged - wash the carburetor
carb cleaner. - 🔧 Incorrect idle speed adjustment - tighten the “quality” and “quantity” screws of the mixture.
- 🛢️ There is no gasoline in the float chamber — check the fuel pump (it is mechanical, driven by the camshaft).
Injector (models after 2006)
The culprits here are:
- 🔌 Mass air flow sensor (MAF) - if he is lying, the ECU is pouring too much or too little fuel.
- 🛢️ Fuel pump - When you turn on the ignition, you should hear a buzzing sound from the gas tank.
- 🔥 Injectors — clogged injectors do not spray gasoline, but pour out a stream (checked on a bench).
On injection VAZ 2107 If the fuel system malfunctions, it often lights up Check Engine. Read errors to the scanner (eg. ELM327) or through on-board computer (if installed).
If carburetor VAZ 2107 starts only “from a tow” or after prolonged cranking with the starter - air leaks through the intake manifold gasket or vacuum brake booster are almost always to blame.
6. Compression and mechanical failures
If all the previous steps did not work, check compression in cylinders. On VAZ 2107 it should be at least 10 bar (ideally 12–13 bar). Low compression indicates:
- 🔧 Worn piston rings.
- 🔥 Burnt out valve (often accompanied by popping sounds in the muffler).
- 🛢️ Cylinder head gasket failure (check the oil - if it looks like “mayonnaise”, that’s it).
Also inspect timing belt (on injection VAZ 2107). If it breaks or jumps several teeth, the valves may collide with the pistons - this guaranteed overhaul.
How to measure compression? You will need a compression gauge (costs ~500 rubles). Unscrew all the spark plugs, insert the device into the first cylinder and crank the starter for 5-7 seconds. Repeat for all cylinders. A spread of values of more than 1 bar is a cause for concern.
7. Prevention: how to avoid startup problems?
To VAZ 2107 started with a half turn, follow simple rules:
- 🔋 Battery: In winter, remove it at night and keep warm. In summer, check the electrolyte level.
- ⛽ Fuel: Do not refuel at dubious gas stations - bad gasoline kills the carburetor and injectors.
- 🔧 Candles: Change every 20–30 thousand km (even if “they work like that”).
- 🛢️ Oil: Use semi-synthetics
10W-40— it thickens less in the cold.
On injection VAZ 2107 clean every 50 thousand km throttle valve and check crankshaft position sensor (DPKV) - its malfunction leads to complete startup failure.
If VAZ 2107 If it sits motionless for more than a month, before starting, remove the spark plugs, pour 5 ml of oil into the cylinders and crank the starter without spark plugs - this will save the rings from dry friction.
FAQ: Frequently asked questions about the launch VAZ 2107
Why VAZ 2107 Does it start and then stall immediately?
Reasons:
- On carburetor — the idle jet is clogged or the mixture “amount” screw is not adjusted.
- On injector - faulty
RXX(idle air control) or air leaking through a cracked pipe.
Check also fuel pump - if it pumps weakly, there is only enough fuel for the first seconds of operation.
The starter turns, but the engine does not catch. What to do?
Algorithm of actions:
- Check spark (unscrew the candle and apply it to the mass).
- Make sure gasoline arrives into the carburetor/ramp (listen to the pump on the injector).
- Check compression - if below 8 bar, the engine will not start.
If everything is in order, but the engine does not start, they are knocked down valve timing (check timing marks).
Is it possible to start VAZ 2107 from the pushrod if the starter does not work?
Yes, but there are nuances:
- On carburetor — engage 2nd gear and accelerate to 10–15 km/h, then smoothly release the clutch.
- On injector — the method works worse, because The ECU may block starting without a signal from the crankshaft position sensor.
⚠️ Attention: Don't try to push start if it's broken. timing belt — this will lead to the valves hitting the pistons!
After replacing the timing belt, the car does not start. What's the matter?
Most likely you set it incorrectly tags. On VAZ 2107 with injector:
- The mark on the crankshaft pulley should match the long mark on the front cover.
- The mark on the camshaft has a protrusion on the rear cover.
If the marks are knocked down, the valves and pistons do not work synchronously, the engine will not start. Double check!
What kind of gasoline to pour into VAZ 2107?
Official recommendations:
- For carburetor models -
AI-92. - For injection (since 2006) —
AI-95.
Usage AI-98 will not give an increase in power, but AI-80 may cause detonation and damage to the pistons.