1997 850R sedan cranks strong, but wont start.

D-Frosty · Post by **D-Frosty** » 12 Sep 2015, 08:42

I just bought it a few days ago knowing it didn't start, the owner before me trying a new crankshaft sensor. I began thinking it was just the camshaft sensor, so I bought it. That didn't work. I just replaced the fuel pump and pump relay because there seems to be no fuel pressure at the rail and it doesn't sound like the old or the new pump are kicking on at all. Anyone have any ideas?

atikovi · Post by **atikovi** » 12 Sep 2015, 09:46

D-Frosty wrote:I just replaced the fuel pump and pump relay because there seems to be no fuel pressure at the rail and it doesn't sound like the old or the new pump are kicking on at all.

Until you put a pressure gauge to it, you are just guessing. You could use starting fluid as a diagnostic aid in these situations.

Sommerfeldt · Post by **Sommerfeldt** » 12 Sep 2015, 15:19

The mantra around here is to diagnose before "throwing parts at it", as the saying goes. While the sensor may have been faulty, you don't know that, and you may have thrown out a good pump and relay because the fault was somewhere else.
Cranking kind of only means that you've got a good battery and the starter can make the engine move... not much else.

- See if the car's giving you any codes to work with.
- Check ignition parts. Anything worn, cracked or busted up? (Plugs, coil, wires, cap/rotor)
- Check for spark
- Check fuel pressure.

Report back.

- S

Post by **misha** » 12 Sep 2015, 18:30

If all of those things sommerfeldt adviced check out ok,then there is a chance that immobiliser is bad or kicked in.
Since U.S cars don't have chipped keys in '96 & '97 models like European ones,immobiliser on them works in a different way.
It's enough to lock & unlock the car 3 times via remote or....if there is no remote,to insert the key in driver's door with all doors closed and then to lock & unlock the doors 3 times.
It's also a good idea to check fuses.There are few of them for immobiliser.

It's a good idea to check ALL fuses.

Master fuel injection relay could also be the main culprit.It's a grey one on cooling fan carrier.It's the only grey one and usually... Made in Hungary is written on it.

Post by **FLXC90** » 12 Sep 2015, 20:20

D-Frosty wrote:I just bought it a few days ago knowing it didn't start, the owner before me trying a new crankshaft sensor. I began thinking it was just the camshaft sensor, so I bought it. That didn't work. I just replaced the fuel pump and pump relay because there seems to be no fuel pressure at the rail and it doesn't sound like the old or the new pump are kicking on at all. Anyone have any ideas?

Under right hand side of car, just ahead and inboard of rear wheel is where the fuel filter is. Place a catch pan, and disconnect line at front of filter, Taking bolt and clamp loose will allow you to move things around. Point filter exit to catch pan (a length of hose here can help) Turn key to pos II and cycle a couple times. Now go see if there is more fuel in the pan. You may not even hear the pump without the pressure backup. I didn't hear mine night before last, but it's all good!

If not, try using a jumper in place of the fuel pump relay (go to the no-start thread in the forum) try shootin the pan again. You can also pull the pump out and test with a jumper harness and a battery, just don't run it too long with no fuel.

Actual tests are the only way to determine if parts are bad. Otherwise, you'll be broke before your car runs like it should. Or you'll get pissed and unload it like the last guy!

Get it running and enjoy it. ALL the info you need is here in this forum, welcome to it

Sommerfeldt · Post by **Sommerfeldt** » 13 Sep 2015, 03:53

Misha and FLXC90 has good advice there - simple and efficient tests which will shorten down the list pretty good.

An 850R is an awesome car, and if you put in a little time to get it running good, you've got an absolutely excellent sleeper/daily driver/race car/whatever you want.

- S

Azik09 · Post by **Azik09** » 14 Sep 2015, 05:57

When immobilizer is faulty, engine will start for 1-2 seconds only. So immo is innocent.
Try this simple checks:
Open fuel tank cap and ask someone to switch on ignition. Is fuel pump operating? It should be heard good.
If you hear noise so pump, pump relay, main relay and corresponding wiring are OK. Next step:
Ask your helper to crank engine for 2-3 seconds while continuing listening for fuel pump noise. Pump must operate for 2-3 seconds even after you stopped to crank engine (ignition is still switched on).
Your next steps will depend of this checking results.