Intermittent no crank '88 951
08-19-2015, 12:48 PM
#1
Advanced
Thread Starter
Intermittent no crank '88 951
Hi guys!
I have an '88 951 with the Vitesse Stage 3 kit (includes MAF).
The problem I am having is that intermittently and only when it's hot, it will refuse to crank. So far, after an hour or two of letting it cool it starts up like normal.
So far I have put in a brand new DME relay. I was hoping this would solve the problem, but it just happened to me again today.
Any advice as to where to start looking next?
I have an '88 951 with the Vitesse Stage 3 kit (includes MAF).
The problem I am having is that intermittently and only when it's hot, it will refuse to crank. So far, after an hour or two of letting it cool it starts up like normal.
So far I have put in a brand new DME relay. I was hoping this would solve the problem, but it just happened to me again today.
Any advice as to where to start looking next?
08-19-2015, 03:48 PM
#3
Rennlist Member
What do you mean when you say it refuses to crank?
Are you saying the starter motor is not cranking the motor over? (If so, think battery, cables, starter, etc.)
Or is the starter cranking the motor but the motor won't start-up and run on its own? (If so, think DME relay, tach bounce, speed/ref sensors, etc.)
Are you saying the starter motor is not cranking the motor over? (If so, think battery, cables, starter, etc.)
Or is the starter cranking the motor but the motor won't start-up and run on its own? (If so, think DME relay, tach bounce, speed/ref sensors, etc.)
08-20-2015, 05:28 PM
#4
Burning Brakes
Ignition switch may be suspect, if you mean the engine is silent and does not even crank.
If the engine cranks over but does not start, consider first the fuel relay, a know problem area. Is it getting spark?
If not getting spark, it could be the ignition trigger in the DME, a round silver transistor which makes a lot of heat and may fail. Or, its solder joints may have hairline cracks, which open when the unit gets hot, due to thermal expansion, interrupting electrical flow, so the car dies. Car sits a while, unit cools off, hairline crack closes, juice flows, so ar runs...until it gets hot again. Reflow the solder joints and/or replace the ignition trigger transistor, about $4 at DigiKey et al.
If the engine cranks over but does not start, consider first the fuel relay, a know problem area. Is it getting spark?
If not getting spark, it could be the ignition trigger in the DME, a round silver transistor which makes a lot of heat and may fail. Or, its solder joints may have hairline cracks, which open when the unit gets hot, due to thermal expansion, interrupting electrical flow, so the car dies. Car sits a while, unit cools off, hairline crack closes, juice flows, so ar runs...until it gets hot again. Reflow the solder joints and/or replace the ignition trigger transistor, about $4 at DigiKey et al.