[s-cars] when would you consider dead map sensor? all cylinders shut down under boost

[Joe Pizzimenti]

Replace all coils & POS's.

30psi is a lot of cylinder pressure.


On 9/11/08, forrest bradshaw <sola4est at yahoo.com> wrote:
> recap: 95 S6, last month car started hitting
> 30psi, then started cutting fuel violently and throwing code for MAP
> sensor signal too low. replaced WGFV and added rs2 em.
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> picked up car today from shop
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> #2 coil new, all coils ohm equally
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> stock WG spring re-installed, backed out to flush with top
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> Pastore's MTM 1+, 3bar vmap, RS2 EM, stromung are motor related mods
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> so, drove car as stated and peak boost was 15 psi, would flutter
> slightly there in all gears, got one 17 psi peak in 4th gear going up a
> small hill bout 3000 rpm, no stutters or hesitations.
>
> back at shop I turned the spring down 4 turns and another test
> drive, now I have 17 psi and then start missing, back off and try again
> same but this time all 5 cylinders shut down in sequence and loss of
> power, felt like driving over a rumble pad before a stop sign. this was
> at 15 psi, try again and it happened at 10psi, tried again and all
> cylinders again shut down at 6 psi.
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> back to shop, ohmed all injectors, they all test at 16.9 ohms. did
> not bother checking for codes again, but previous test drives threw no
> codes, not even the MAP code I have been getting before new coil.
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> backed spring out again and still get fuel cut or massive miss under boost,
> cannot even light throttle pass another car now.
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> no boost leaks, manifold to MAP hose is fully attached, did not
> pressure test it yet, did not want to start cutting clamps or zip ties
> (boost gauge line is zip tied to T fitting at ecu as of last october)
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> Figure before I do that I will swap ECUs with Elijah's wife's avant
> as it has the same software as mine, just gotta catch Eli, he has
> family in town.
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> Hell what is going on here??? should I assume the ECU is shutting
> down the cylinders on purpose, why at consideraly lower boost
> pressures? can Vmap go bad? is it possible the ECU somehow went back to
> stock configuration?
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> could my couple 30psi spikes last month have killed the Vmap?
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> Vag tested the WG solenoid and other devices and they worked, tried
> to test the injectors with the scan tool and nothign happened, also
> tried this on a stock S6 and nothing happened
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> so sad in Michigan
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