96 850 not starting sometimes

Post by **abscate** » 21 Jun 2019, 10:12

Two ways to isolate the fuel vs spark diagnostic tree

1 Measure fuel pressure with gauge. Hearing the pump is not enough, these cars need spec fuel pressure to run.

2 Starter fluid on the no start condition. Easier to implement when the no start is intermittent.

A three second shot into the air cleaner snout will give you a quick burst of running if your igntiion is good.

greg850r · Post by **greg850r** » 29 Jun 2019, 21:41

Clemens wrote: ↑18 Jun 2019, 05:38 After truning over, remove a spark plug and see if it is wet or smells like fuel. If so, you might have no spark. Otherwise not enough fuel.
There is also a good chance that it is the engine coolant temp sensor. If it is faulty you might get a no start situation.

Anybody got more on the coolant temp sensor causing a no spark? I have a 96T wagon I started another thread about a few months ago and never have figured it out.

96 850 turbo no spark, most of the time

Post by greg850r » 31 Jan 2018, 09:55

Post by **abscate** » 30 Jun 2019, 04:39

A bad ECT will not inhibit spark but you May have more than one problem.

When was the last time the plugs cap rotor and wires were serviced?

mattconrad850 · Post by **mattconrad850** » 30 Jun 2019, 07:16

Had same issue, turned out it was my fuel filter, ran great but in the sun (strange) hot weather wouldn't start, once the outside air was cooler it would fire right up, got stranded 2x had it towed, cranked fine, tested for pressure at shrader slight surge then nothing, removed fuel feed tube and no gas in there at all, filter was full of gas, had other issues too which made finding it difficult, mostly evap issues, hoses split

greg850r · Post by **greg850r** » 06 Jul 2019, 09:31

abscate wrote: ↑30 Jun 2019, 04:39 A bad ECT will not inhibit spark but you May have more than one problem.

When was the last time the plugs cap rotor and wires were serviced?

Plugs, cap, rotor, wires, cam sensor, crank sensor, coil unit all swapped with those on a running car to no avail. I'm really chasing my tail on this one.

shegarty · Post by **shegarty** » 06 Jul 2019, 09:58

Have you ruled out a fuelling issue yet? Low pressure or lack of volume could be a problem.

greg850r · Post by **greg850r** » 06 Jul 2019, 17:26

Fuel pressure was good and it was lacking spark the last time I was working on it.

Here's the thread from the last attempt to get it running.
viewtopic.php?t=84297

greg850r · Post by **greg850r** » 08 Jul 2019, 19:38

I just changed wires, cap, rotor, cleaned and gapped plugs and found the ECT plug was losing connection so I took it apart and cleaned the connectors with emory cloth and removed them from their holders so I could positively attach them. While I was at it I cleaned and reattached cam and crank sensor plugs. Sprayed some starting fluid in the intake by the radiator and it popped but that's all. I went for the lawn mower syndrome and just cranked it throttle on the floor for the longest time. When I gave up and released the key it fired and revved because my foot was still on the floor. I let it run until the temp gauge moved and shut it down. Tried restart and had to crank it wide open again but it fired a little quicker this time. It ran fairly well when it quit on me but sounds pretty bad now. I think it sat too long. Valve train noise still there when warm and I bet the rings are stuck. I'm going to pop the plugs back out and add about 4oz Marvel to each cylinder and call it a night. This must have been a combination of things but as long as I have you guys to throw ideas at me I don't give up. I've let this one sit for months at a time and probably that added to the problems I had making it go. Thanks for all the suggestions guys. I'll report back in a few days after I run it in and make a few more tweaks.

96 850 not starting sometimes

Re: 96 850 not starting sometimes