Running rich... Injector pulse width? / MAF signals?

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08-15-2007, 09:02 PM

gl1970

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Running rich... Injector pulse width? / MAF signals?

Hello everyone,

I've got a '92 240 (B230F, LH Jetronic 2.4) and I'm having some problems with the engine running extremely rich (lots of black smoke). The pulse width on the injectors seems high (3.5 to 7ms). I've tested the following components:

- Temperature sensor (2.5K ohms cold, about 300 ohms hot).
- Fuel pressure regulator is working well.
- Knock sensor appears to be working.
- Fuel Injectors (aside from the large pulse width they're good).
- Fuel pumps/relay are good.
- Wiring harness is good.
- O2 sensor was recently replaced with a new Bosch unit.
- Vacuum lines are intact and don't appear to be leaking.
- Air filter is good, intake is clean

Does anyone know what the official specs are for the AMM/MAF sensor? I've tested the resistance per the Haynes Manual test and it passes but I'd like to know what voltage/signal I should expect on the pins throughout it's operating range.

Also, does anyone know what the pulse widths should be?

Thanks in advance,

Gord

-------------
'92 240 Sedan

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08-26-2007, 09:55 AM

JAKESTERS

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RE: Running rich... Injector pulse width? / MAF signals?

There are ground wireson the intake 10m bolt.humm wire color brown..... if i rember.Try cleaning them 1st.

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08-27-2007, 05:45 PM

Kruspe31

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RE: Running rich... Injector pulse width? / MAF signals?

is there a fuel leak?

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08-28-2007, 02:40 PM

outofworkjoe

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RE: Running rich... Injector pulse width? / MAF signals?

Leaks in your intake will cause this,crack vac lines.Have you pulled your intake hose of and check for cracks in the ribs?Pull rear vac line off your F/R check to for fuel ,no fuel its good.

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