Suub 2.5 with a Quirkey start

[reelmule]

My Suub fuel injected 2.5 runs great but usually won't start on the first crank, even after 10-15 secs. However if you turn the ignition switch to off while cranking and then immediatley back to run it always starts immediately. It makes no difference if the first crank time is 3 secs or 20 secs. This of course results in a bit of grinding on the starter bendix. WHAT IS GOING ON HERE???

 

[Passin' Thru]

Walt, my VW Sirroco with Bosch fuel injection had the same, -I won't say problem, but symptoms. I learned that in all that electronic wizardry the starter circuit started the injector boost pump and "enrichner" thru an interval timer. If the engine for whatever reason did not start within that interval, it cut off to prevent flooding and washing down the cylinders with excess rar gasoline. Over a period of years some componant, a resistor or capasitor, lost its spec value and the interval became too short. Turning the ignition off reset the timer and back on again restarted the time and usually there was enough gas there to complete the start. Once the engine starts, the timer is by-passed. You situation may or may not be simular. I eventually replaced the start sequence module and never had the problem again.:noidea:

 

[cgmg]

Walt,

Your symptoms don't sound quite the same as my engine, but mine gradually became harder and harder to start on the first go-around. Especially warm it was a bigger problem. Then, it just refused to start at all one day.

After all kinds of trials and errors, even with a Sub mechanic checking it over, still couldn't find the cause and get it started. Stumbled across a spare MAP sensor I hadn't switched out yet, and voila!!!!, it starts and runs like a champ now. It may be that yours is failing.

I bought another spare off of eBay for less than $30. It now goes wherever the gyro goes. Try getting yourself a used MAP sensor, you're only out $30 to see if that's it.

Let us know what you find out.

 

[lanichol]

Walt,
After all kinds of trials and errors, even with a Sub mechanic checking it over, still couldn't find the cause and get it started. Stumbled across a spare MAP sensor I hadn't switched out yet, and voila!!!!, it starts and runs like a champ now. It may be that yours is failing.

Unplugg the map sensor and give it a try.

 

[reelmule]

Pete, Mark, Larry,
Thanks for the imput. I have been following your thread, Mark, and will check the MAP out with my friends part. I really suspect it is closer to what Pete decribed with his VW situation. Again, thanks to all of you for the imput. Pete, I'm not sure if the Suub has a starter sequence module??

 

[Passin' Thru]

I really suspect it is closer to what Pete decribed with his VW situation. Again, thanks to all of you for the imput. Pete, I'm not sure if the Suub has a starter sequence module??

Walt, the Sub probably has it incorporated into the "computer" as does the later VWs. Someone who has the diagnostics computer may be able to read it or even re-program it. All this new modern magic stuff is way beyond my experience!