hello i have an xj8 that will not start... there is no check engine light on, i was told by a mechanic that the fuel pump was toast... so i replaced that and new fuses/relays still no start. i checked the fuel rail it is getting fuel but will not start still? i am thinking it may be a bad crankshaft sensor? any help would be greatly appreciated.

 

You will have to tell us quite a bit more, in fact all you know about what did or could happen, otherwise it gonna be guessing in the dark
for starters does it crank at all? was it starting in the past or you got it as is?

 

With the ignition key on and not trying to start the engine, is a check engine light on then?

 

yes it was starting then the water pump started to leak so it sat for a month or so then we fixed that and tried to start engine.. it would not start. mechanic said it was fuel pump because no fuel was getting to the fuel rails.. so we replaced the fuel pump and still no start. It will crank but will not start at all.

 

no

 

one month is not that much, it could be crank sensor but it rather didn't die of doing nothing during that month so it is not that probable.
Is your battery fully charged? does it sound like almost starting or just cranks without hope?
Some easy things: maybe it is flooded after playing with fuel pump, try to crank it with gas pedal floored or if that doesn't work with fuel pump relay removed

 

yes battery is fully charged. i mean it sounds like it wants to start , i have tried cranking it with gas pedal on floor i havent dried doing it with fuel pump relay removed though.

 

if it is almost jumping then it may be flooded, cranking with gas to floor should clear cylinders but for me somehow didn't so i removed the relay and it actually started for a second then died of starvation, after reinserting relay started normal, try that

 

Do you have a scanner to plug into your car?

When the key is turned to position 2, the car does a bulb check of the instrument pack (IP) and it’s very important that CEL bulb lights up. If memory serves me, that specific bulb is actually an led that’s hard wired into the IP.

 

there is no check engine light so i cant scan it.

 

OF COURSE YOU CAN SCAN IT!!!!!!!!!!!

Just because the MIL is not illuminated does not mean there is no DTC.
A 'pending' DTC will not turn the CK ENG light on.

 

what i meant was i am not getting any trouble codes from the scanner

 

Bob, I was simply trying to find out if there was any kind of a CEL on with the key on and engine off. You know as well as I that there must be a CEL on during the bulb test (ignition key on engine off position 2) of the IP to see if the ECM is alive. It doesn’t matter if there’s no codes, pending codes or 5 pages of codes stored in the ECM. I know you have significantly more experience with the jags and I only have 10 years but, I can honestly say I’ve not encountered a burned out led specifically for the CEL itself during my time with the jags.

Jermyc, if what you say is true that you have no CEL with key on engine off, are you able to communicate with the ECM (or any other system) using your scanner?

 

yes i can

 

Well as long as the scanner communicates with the ECM, that’s a real good sign. In this instance I’m with XJack to say that it’s flooded.

I would have a battery charger or jumper cables from another running car to help do the start method. The repeated cranking idea is to 1) clear out the flooded cylinders and 2) heat up the piston rings so they’ll seal up to the walls to create as much pressure as possible. If you crank only with the vehicles battery power, there’s a good possibility that you’ll continue to have a flooded issue. These cars DEMAND a strong battery to keep all the modules happy while your cranking the engine over with strong voltage AND amperage. Some people have good luck with the oil in the cylinders method but I haven’t had much luck with it. I myself just keep the gas pedal to the floor and crank the engine over for about 15 seconds at a time, turn the key off for about 20 seconds then foot to floor crank about 15 seconds and off 20 seconds. I do this method about 3 times then I try to start the engine with foot off of the gas and see what happens.

 

It sounds a lot like bore wash to me.

 

Yep. Pretty classic bore wash: keeping the throttle pedal on the floor to cut off fuel flow (which causes bore wash) does not alway provide enough oil in the cylinders to provide compression if it has been sitting for a while. Pull a couple of plugs and eye dropper engine oil into the cylinders, try to start with pedal to the floor.

 

UPDATE: I tried all the methods to clear the bore wash and still no luck.. I ended up replacing the Crankshaft Position Sensor, Now it is throwing the check engine light. so i will scan it in the morning and hopefully come back with some codes!!

 

You can usually test the CPS with a digital Multi-meter.
That may have been fairly close to the top of the list on
things to check, especially with no code from the reader..

 

i am getting P0335 crankshaft position sensor circuit fault

P1638

P1111

P1794

C1095

B1202

only thing i can think of that would make a no start situation is the crankshaft code? i cleared all the codes and only B1202 showed back up.