hard or no start-no codes found

uncledave11 · Post by **uncledave11** » 06 Jan 2012, 09:02

Trouble with my son's 95 850 turbo. without warning it will fail to start. no codes found after scanning. fuel pump relay updated with hi temp caps about a year ago. sometimes will fire up immediately, other times will take 8-10 cycles (short crank tries to protect starter from overheating). sometimes just letting it set 5 minutes and trying again. no gas smells, no cylinders firing at all, then suddenly may "pop" to life and idle smoothly. No driveabilty issues, runs strong! Very strange! any suggestions on where to look first?

thx,

Dave

Post by **jblackburn** » 06 Jan 2012, 09:37

DOES the car have fuel pressure at the rail when this no-start condition occurs?

uncledave11 · Post by **uncledave11** » 06 Jan 2012, 12:59

good question! Unfortunatelty I'm going to have to rig up a test gauge that I can put into place quickly as is difficult to monitor this parameter when it occurs will my son working odd hours. ofcourse it will never exhibit to no start problem until you forget about it. Still (according to my son) this doesn't occur when he's out going from place to place making short stops. So... I'm assuming this only occurs after a several hour or over night cool down. Make's me wonder if it's getting a shot of fuel all this time during cold startup key cycles. Hmmmm-thx

Post by **jblackburn** » 06 Jan 2012, 13:03

Ask him to take a close look at the temperature gauge. Does it warm up to 3:00 position after 5 minutes or so and then stay planted there as he's driving?

A bad/intermittently acting up ECT sensor can leave you cranking forever without enough fuel being injected to start a stone cold engine. Just an idea.

uncledave11 · Post by **uncledave11** » 06 Jan 2012, 14:05

pretty sure the temp gauge is normal. In fact it's the fastest warm up cycle of any car i've ever owned! you get heat in 10 deg. weather within a mile of leaving the house. So I'd wager the warm up cycle is normal. I'm going with my gut to electrics. Just for kicks I pulled the Fuel pump relay I fixed a year ago for a close inspection of the solder joints. They looked fine but I'm suspicious of the 100 uf cap I replaced. I know in circuit values are not always accurate but... I have a nice fluke dmm that does a nice job checking caps. I got about 24.7 uf on the 22 uf cap but the 100 uf climbed up to about 437 uf when tested. This might be caused by another cap in the circuit but I think I'm going to put in a new one just to be sure. Caps usuallly fail (leak) if going south when tested but what the heck, i might as well be sure, right? Thx for the tips..I'll share the cure when i find it!

Dave