1994 xjs 2+2 with 4.0 inline 6, crank but no start. Did some head work and now no start. fuel pump new 50lbs. pressure at fuel rail, injectors cleaned and working. new fuel pressure regulator, iac valve, cps sensor, coil, spark plugs and wires all new. on reinstalling the cams I used the cam shaft setting tool. I have spark and power to the fuel injectors. Help please.

 

Does it fire if you spray some gasoline, carburetor cleaner, or something similar into the intake?

 

No, I tried with starting fluid and still did not start

 

also when I set the cams with the cam set tool and number 1 cylinder at tdc, the distributor was still in the engine, so the rotor was then pointing to the number 1 spark plug wire on the distributor cap

 

John,

Just trying to understand, what you meant when you said you had spark and power to injector. To clarify, when you crank the starter:

- Do you have spark at a spark plug (pulled out from the cylinder)?
- Do you have fuel spraying from an injector (pulled out and placed in jar)?

Paul

 

yes I have spark with the plugs out of the cylinder head, but I did not try a fuel injector removed and put in a jar. That is a good idea and I will try that soon.

 

Hi miamijohn

Could be the 'Coolant Temperature Sensor'

Set your Meter to Ohms, pull off the plug and then put the Probes of your Meter onto the 'Coolant Temperature Sensor' where you will hopefully get a reading of at least 2 ohms

Any less and your 'Coolant Temperature Sensor' could be the problem, as this sends a Signal to the ECU to fire the injectors

To double Check, Bridge the Plug with a Paper Clip or a piece of Wire and then see if She Starts

 

Thank you Paul and Orangeblossom, Those are ideas I could never have come up with on my own.
John

 

John.

It SEEMS that you have ignition sparks, pumped petrol flow to the fuel rail, and static power flow to the injectors. But it sounds like maybe the injectors aren't firing on the start sequence.

As OB has suggested, the CTS can cause that. Check the CTS and also check an injector whilst cranking the engine.

Cheers

Paul

 

Bought new CTS, old CTS had 3.1 ohm's new CTS has 2.7 ohm's. Still no start. Will check the fuel injectors next as Paul suggested.
John

 

Hi miamijohn

Couple of more suggestions

Fuse Box behind Passenger Side Knee Panel (UK Car)

Check all the Fuses, as one of those Fuses is the Fuse for the ECU (which could be a bit flaky)

Also Check the 2 X Big Blue Relays that are just above those Fuses a bit hidden out of the way, that may not be making Good Contact in their Holders, so take them out and put them back again and jiggle them about, as this caused a problem on my 1995 4.0L

If none of that works have a look at my Thread 'Carmen Won't Start' Pages: 93 to 95 where I tried almost every 'Trick in the Book' to get her to Start and She Finally did!

Don't overlook the obvious like Not enough Fuel in the Tank, as even 10 gallons is hardly enough to reach the Fuel Pump Sock Filter

'Carmen Won't Start' Almost every 'Trick in the Book' to get my 1995 XJS 4.0L to Start which She Finally did!

 

Did you check the inertia cutoff switch at the passengers door?

 

Vee,
I don"t think the 94 xjs 2+2 has the inertia cutoff switch, but I will investigate further.
Thanks, John

 

Thanks OB,
I will do your wiggle test.
John

 

Vee,
I was wrong there is an inertia switch, but i am getting good fuel pressure at the fuel rail and if I am correct the inertia switch disconnects the fuel pump. Is my assumtion correct?
John

 

Sunday update, I unbolted the fuel rail and left the fuel lines and injectors attached. All six injectors (which are new) sprayed fuel upon cranking. At least this verifies there is voltage to the injector connectors. All the relays, 2 blue and 1 violet, under the passenger knee bolster tested good. the violet relay says it is the EMS power relay I will check all fuses again.
When I crank the engine the tachometer barely moves at all and the CPS is new. Could it be that the gap for the CPS is off and not sensing when #1 cylinder is at TDC? So even though there is spark and fuel, the spark is not firing at the proper time?
John

 

Hi John

Gap too wide on the 'Crank Position Sensor' sounds a very real possibility and should have a MAX Gap of 0.042 any wider and the ECU won't Trigger

And the fact that the Tacho hardly moves when you Crank the Engine, is a very good indicator that the problem lays in that direction so if you can adjust that Gap then you could be on a Winner and She 'might start'

If you can somehow adjust that Gap and then get the Probes of your DVM Meter (Set to Volts DC) into the Plug of the 'Crank Position Sensor' and then Spin the Engine while of course 'Minding Your Fingers!' then you should see a Constant Voltage Fluctuation as the Engine Spins

Or just adjust the Gap and do it that way

Don't go throwing your Old Crank Sensor in the Bin just yet as it might still be OK and could be kept in the 'Glove Box' as a Spare for a Roadside Repair which can be done in just a Couple of Minutes (once you have done it before) so you know where that bolt is, as you cannot see it when your hand is holding the Spanner

It has to be done by feel

How to Test your Old 'Crank Position Sensor' about 1/3 the way down on Page: 120 of my 'Cherry Blossom' Restoration Thread

How to Test the Crank Position Sensor on a 4.0L 6cyl XJS

 

Thanks OB,
I am going to pull the cooling fan, shroud, and radiator to give me clear access to the CPS. I also want to check that I have the toothed crankshaft gear timing sprocket positioned correctly so it is on center with the CPS. When I reset it after removing the front cover, I may have set it too deep or too shallow on the crankshaft nose. I have a "big boys" 1 inch socket set to remove the crank bolt if needed.

 

Yes, assumption is accurate. Just thought I'd cross off the very low hanging fruit.

 

CPS update: I removed the radiator and cooling fan shroud for easy access to the CPS. I had the toothed sprocket on the harmonic balancer aligned correctly to the CPS, however even without putting the feeler gauge on it, I could tell the CPS magnet end gap was way too large. The old CPS and the new one are exact in dimensions, so I can only conclude the old CPS has a stronger magnet and thus can pickup a signal from further away from the sprocket. So my question is, Does the barrel end of the CPS with the magnet screw in and out for adjustment?
John