MEFI4 troubleshooting hard start

[Fast355]

does the MAP play a role during cranking, or it is just after the engine is running? From my gateway data, the reading seems OK if I compare to the weather forecast...

Maybe Carl can shed some light because I have not played with a MEFI controller in a decade. My 0411 has a Cranking VE table that has RPM and MAP as a reference. A bad MAP on alot of GM stuff can cause hard starts but usually shows up as more of a rough or rich running immediately after startup.

I bought a genuine Bosch T-Map for my marine intake for about $30. Mercruiser and Volvo Penta mark them up about 500%. I will see if I can find the Bosch part number.

[Fast355]

My guess is it is the same one I had. 0-261-230-075 but you should be able to confirm the Bosch number and search it up for a replacement if it is not.

https://www.ebay.com/itm/324135895105

[Turbo_Bimmer]

My guess is it is the same one I had. 0-261-230-075 but you should be able to confirm the Bosch number and search it up for a replacement if it is not.

https://www.ebay.com/itm/324135895105

I looked today, and it is painted red like the rest of the engine, so no number to refer to...

I took the time to unbolt the crank sensor. There was some clean oil on it. I'm not sure if it matters though. Cam the oil sneak inside and affect it?

IMG_20220812_084332.jpg

[Fast355]

I looked today, and it is painted red like the rest of the engine, so no number to refer to...

I took the time to unbolt the crank sensor. There was some clean oil on it. I'm not sure if it matters though. Cam the oil sneak inside and affect it?

IMG_20220812_084332.jpg

Oil can leak into the crank sensor if it is damaged or cracked, but the oil on the metal nose is nothing to worry about. The reluctor wheel sits right in front of the timing gear. Lots of oil in there when it is running. Usually if the crank sensor is getting oil into it, it will drip out of the wiring connection end.q

[In-Tech]

Good call Fast. The cal does show it to be the Bosch MAP sensor that has built it IAT. Personally I would wipe the metal fuzz off the crank sensor, get a new map/iat and also coolant temp. Have a look at the cam sensor distributor and clean the rust out, a delphi cam sensor if need be.

[Turbo_Bimmer]

Good call Fast. The cal does show it to be the Bosch MAP sensor that has built it IAT. Personally I would wipe the metal fuzz off the crank sensor, get a new map/iat and also coolant temp. Have a look at the cam sensor distributor and clean the rust out, a delphi cam sensor if need be.

If the MAP/IAT sensor is bad, wouldn't it make the same hard start conditon every time I crank the engine?
Because if I have a hard start, then I turn the engine off, I can restart it in a quarter turn, for 10 times if I want.
It is hard to start after 20 minutes of resting or more, exept when it is a colder temperature like at the end of the summer.
Like if there was extra gas inside the intake manifold.
But If the boat is in my driveway for a week, I suppose the gas would evaporate if it's the problem, but the engine is still hard to start, for the first start.

I don't think I have a cam sensor. You mean the trigger module inside the distributor? with the 8 points disk?

[Turbo_Bimmer]

Oil can leak into the crank sensor if it is damaged or cracked, but the oil on the metal nose is nothing to worry about. The reluctor wheel sits right in front of the timing gear. Lots of oil in there when it is running. Usually if the crank sensor is getting oil into it, it will drip out of the wiring connection end.q

No oil to be seen on the connector. Is the crank sensor inside the timing cover (with oil)?
I tought it was outside of the timing cover, so, if inside, it is normal to have oil on it, my bad.