99 BEETLE BOGS/MISS ON HARD ACCEL, KRIMP FUEL RETURN NO PROBLEM
HAVE REPLACED FUEL PUMP, FUEL PRESS. REG., PLUGS, WIRES, COIL, AND INJECTORS. FUEL PRESS. @ IDLE IS 42PSI AND INCREASES TO 50 WHEN BOGGING/MISFIREING. MISFIRE CODES FOR CYL. 1, 3, &4. HELP!!!!!
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Do you have any codes besides P030x? Are you using the stock 1999 5.2 PCM? Do your short-term and long-term fuel trims show anything more than + or - 10? Are your O2 sensors showing normal voltages? You give a long (and impressive) list of modifications, but have you had diagnostics run through the PCM. It is what's controlling timing and fuel delivery. If the problem isn't mechanical it's got to be in the control. If you don't have the gear, invest in the services of an experienced ASE certified mechanic.
Hi William, The fuel pump pressure is correct but the fault reading you followed means low voltage signal into the TPS. Seems you may have replaced the wrong part? I would think that the problem is with the mass air flow sensor or the ECU as that is where the signal comes from. Regards John
Could be several possibilities none of which I may be able to eliminate:
1. Tune-up! You are not getting enough spark or Fuel! Plug-wires may be cross-firing or bad ground from body to the engine - run a new ground wire to engine from battery or body-ground. 2. Replace fuel filter or do fuel pressure test to determine if f-pump is weak or lodged with corrosion or dirt particles. 3. replace plugs and wires and clean coil-pack ignition module (where plug wires originate from) use a brake-cleaner or throttle-body cleaner but be sure fumes are evaporated and dry before starting or spark could cause explosion from fumes. Oil on module could cause spark to jump. Do not run plug wires along each other or will jump spark, wires must be crossed once or twice for prevention of this.\ 4. check all vacuum lines around engine - a cracked vacuum line can cause a lot of problems. 5. injectors may be dirty or bad - easier to replace complete intake from scrap-yard then to pay $100.00 for new injectors each! 6. Coil-pack on ignition module could be cracked and may need to be replaced. These are only possibilities of course with the little info you provided. Hope this helps.
Use premium. If you use reg and hear knocking sounds, that is a problem.
Your misfire is most likely a bad spark plug. Make sure that you use OEM plugs only. Any other plug can ruin your ignition coil. Check the plug wires resistance with an OHM meter. Any out of specs need to be replaced.
It is possible the coil is damaged, but can be checked the same way as the plug wires.
Check for clean air filter.
If this doesn't solve the issue, then go through the fuel system. Change the fuel filter. Listen for constant ticking sound in fuel injectors. Use an injector cleaner in the next fuel up.
Good Luck!
Could be several different things.
In need of tune up such as plugs,wires.
Poor connections at coil packs or faulty coil packs.
Dirty fuel system,fuel filter or injectors,fuel pump (such as low pressure),fuel pressure regulator.
There are other things that can cause this but this is the first line of inspection.
check intake for vaccum leaks,the gasket also and egr valve, thats alot of parts to have replaced without diagnosing first, if there are no fuel leaks and you said all injectors were replaced then you have a defective fuel pump, also these engines had misfire problem because of dirty injector but you replaced them so count that out. good luck.
ihad the same problem.. its not the coils or anything like that.. and any reg mechanic wont know the prob unless they under vw.. u need to replace ur power output stage.. thats what cylinder 3 misfire is.. after i fixed it my car is good as new. i
If you have a miss fire it's probably the wires, plugs and coil pack and is it a 4.6 v8 or a 4.2 v6. Its rare that the injectors on a Ford ever go bad. They have the best injectors in the car industry.
Tune ups are easy on both v6 and v8's.
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