Hi everyone

 

My daughter’s car was pounding heavily at the exhaust manifold with erratic rpm, power loss, hollow acceleration as soon as it is hot and loaded. She’s untranslatable in the state.🤒

It starts without worry, shows no odorous smoke or color, stable idle (1100tr cold, 800tr hot). no over-consumption of oil or LdR but I find that the consumption is a little high (approx 8.5l/ 100km - no highway)

As soon as I go up my parking exit (so I shoot the regime), it backfired. ... FORSCAN indicates random combustion failures, on 4 cylinders but especially 2 and 4.

I checked the spark plug set (1.3mm), changed the joucomatic, tested other ignition wires
a new throttle box was mounted.
By removing injectors 1 to 1, no change on the engine. I tested them with a personal assembly, they seem ok. By conscience, I put 2 new injectors on cylinder 2 and 4.
no suction noise at the intake manifold (I do not feel leakage)
the 2 lambdas respond correctly.
I changed the motor fan (burned motor) but my daughter told me not to have noticed it and never had the temperature witness (it is possible, it was quite cold and wet in recent days)

Just so you know, the car had a big storm in the spring, so I had to tear down all the carpets to dry it out. Some corrosion on the candles.


I start to have no idea, I plan to:
- disassemble the petrol pump and check for water in the tank, I believe the fuel filter is built into it
- check the ignition distributor (could a damaged pinion create an ignition offset? more spare parts available! )
- take the pressures of the 4 cylinders
- test one more time the candles, or lower the clearance to 1mm

 

with FORSCAN, no other defects than random combustion failures. The 2 pedal sensors are consistent. the throttle box is open at 7% in idle. 

I have the ignition advance is around 55° (is this normal?) 

all the good ideas are to take . thank you in advance, see you soon. Arnaud

ps : sorry My english is very poor , thanks to reverso !!! 

On 11/27/2023 at 11:19 PM, arno72 said:

new coil, new wires
I sorted among my sparks those that had a very tight resistance. I brushed them vigorously (apparently the problem begins with spark wells that facilitate corrosion - I guess the spring storm is on origin) and I reduced the gap from 1.3 to 1.1 mm.
No more misfires on the roll (controlled with Forscan)

cost 50€