So after my admission of installing the distributor 180 degrees out the car is now refusing to start.

To summarize, the engine has just undergone a full re-build top to bottom, i know the fuel circuit is fine and i am seeing a reasonable spark. The car really really wants to starts as it keeps catching but then never actually makes it to a running state, i'm thinking fuel is my problem, i jacked the car up last week and drained out fuel from 1 tank, i lowered the car to the ground and my fuel tank seal arrived in the mail, i pulled the big plug again and more fuel started to come out with nowhere for me to put it, i decided there was probably not a great deal in there so left it and put about 5 gallons of fresh fuel in reasoning the mix would be a great deal more good than bad.

I should probably check the fuel pressure regulator with a gauge to see how much pressure it's getting, i would have thought if they go bad there would be much more fuel than less, also the garage does not really smell of fuel even after a good long while trying to start.

Any thoughts please

thank you!

Russell

 

Not quite sure what you mean by 'reasonable spark".

You need a bright white-blue spark at the plugs. If you're getting just a yellow-ish spark, that might be the problem and obviously needs to be traced out. Coil, distributor cap and rotor, things like that.


Stale fuel can be a problem, yes. Many variables on gasoline life. How long has it been in the tanks? A couple years? That might be a problem. A few months? Probably not a problem.

My experience, with the fuel we have up here in the PNW, at least, is that fuel that is stale enough to prevent starting will have a strong unusual odor....like turpentine.

If you DO have stale fuel you'll have to purge pipes and filter to get fresh fuel to the fuel rail. Disconnect the supply hose at fuel rail and arrange a container to safely catch the fuel, put the gearshift in "D", and turn the key to 'start'. This will run the fuel pump to flush the system but the start will not engage because you're in "D".



A pressure test is a great idea. Remove the hose to the cold start injector from the fuel rail and use that nipple for your pressure gauge. Your looking for 35 psi while cranking.

Might check the fuel filter, too. Any crud inside? Empty the contents of the filter into a clean jar to tell.

Are the injectors clicking while cranking? If not, since you had everything apart, check that the bundle of ground wires has been reattached to the rear of the water rail. If not, the injectors won't fire.

Cheers
DD

 

Fires but won't run? Jump that coil + term to 12v just to take the whole switch out of the equation.

 

Doug

Fuel has been in the tanks for just over a year so probably long enough. The intensity of spark is leaving me with questions so i will look there, i did replace the original with a Petronix set-up + new coil just before the re-build so even though it was working previously i cannot discount as a potential issue.

Last night i ran through the fuel pump check with the sticky on this forum which proved all was well in that regard.

I did check the injectors and i could not hear them click but of course the starter makes quite a noise, should you easily hear them over the starter?, i will check to make sure there is 12v going to the harness tonight

I did look at the 2 black ring tags (ground) at the back of the intake mainfold and re-seated them, there is also another unsheilded ground at the front between the water rail and the mounting stud for the intake, i did paint the whole intake whilst it was off along with sending the injectors to be cleaned/rebuilt, tonight i will look at that connection. I can always test with a length of wire from the "-" terminal of the battery and land it on the intake manifold to ensure a good ground connection.

Of course timing might still be an issue but even with a number of degrees out of factory it should start and run, albeit not very well of course.

Need to buy a cheap pressure gauge also, i have seen people talk of harbor freight so might pay them a visit tonight, the NAPA auto parts type of store have the $50 full-on kits which is beyond what i need for this test.

Will report back on how things go

Thanks

Russell

 

Other thing to consider is the fuel pump relay contact in the Mass Air Flow Meter. On starting, this is bypassed in the engine start circuit. When the driver relaxes the ignition key when the engine starts, this contact closes and maintains the feed to the fuel pump relay. If it is not closing properly, when the engine starts and you relax the ignition key, the feed to the fuel pump is lost and the engine cannot run as there is no fuel pressure. I would think almost all Series 3 cars will have suffered this syndrome sometime. It is mentioned by Roger Bywater of AJ6 Engineering in his internet article on the XK fuel injection system.

Fuel injection and the Jaguar XJ6 4.2 Series 3 / AJ6 Engineering

See bottom paragraph of the left column

Of course it may not be this !!

 

Fraser..

I was able to prove that the switch in the AFM is closing simply by manually opening the flap whilst the ignition is on and i could hear the pump turn on, it never really gets to the stage of starting that would allow drawing enough air to operate by itself, it simply cranks with multiple fires but no run condition, id almost rather it failed totally as then it would be easier to diagnose.

Lots to look at tonight, will hopefully solve the mystery in short order.

Thanks

Russell

 

Sounds like the plug leads are out of order.

 

So a little update, i checked and 12V at the injectors (both leads) with the IGN on, i checked around a few other items and i thought about timing again so played with a few settings and guess what, it fired and held but not for long, retarding the timing a good margin certainly helped and it looks like UKcat might have a point, i might have statically timed on the wrong lead..

When running the engine was not controllable, i would plant my foot to keep it running only for it to start to rev, letting my foot off just let it die, further retarding just caused blow back through the AFM which i know is bad.

In order to statically time i used a test light, one lead to GRND the other to the - terminal of the coil, turning the distributor until the light came on, however i know the spark is sent when the rotor arm comes in line with #1 lead (which i had about the 11 o'clock position which must be wrong).

When the engine went together i used a dial indicator to set TDC and then attached the pointer to the timing cover, i then set the cams with the alignment tool and tensioned the chain and rotated the engine multiple time to gain a level of repeatability with the cams lining up again when the pointer said TDC.

I have a feeling i am still looking at a fuel issue as the car will not stay running, bad furl of weak mixture perhaps.

Could it still be the regulator (Not yet purchased a gauge to check pressure)

Thanks

russell

 

Yes.

The system is somewhat forgiving but, still, your pressure needs to be in the ballpark. Too little and the engine under fueled; too much and the engine will be over fueled.

Sometimes a regulator will develop an internal leak and raw fuel is sucked into the cylinders. Pull the vauum hose...any signs of raw fuel?

Have you looked at the spark plugs? Are they dry or wet?

Cheers
DD

 

HMMM, That test light method of setting the static timing is either incorrect or I just don't get the logic from your description.


Indeed, way back to coil and condenser ignition, a lamp in series from the - of the distributor to - on the coil could be used to dente when the points just closed. And HT sent by the coil to the distributor. And, if the rotor was directly pointed at the #1 tower on the cap, timing was correct. Usually somewhere around 10 BTDC.


I would guess that the Pertronix using electronics to make and break might work in the same way.


Wiggling the distributor to get it to run at all is a strong clue that timing is off. Rethink and reset in order, all of it. Leads in the cap in the proper order, commencing at the real number 1. Nearest the fire wall on these engines. And determining distributor rotation CW or CCW. Hence in another way of putting it back to basics.
O'wise, the trail is endless.....


Carl

 

Carl

I am 100% in agreement, the timing is certainly one of the main problems here and i need to look at the static timing method again as it's not working out too well, my plan is to re-set all the leads to the cap (Using #1 at the back) and try again, my impression is that when the rotor comes into contact with #1 lead its not at this time the spark is sent but when it leaves #1 on the cap, i.e the same as when a points and condenser set up send the spark, when the points open rather than close.

With that said i am certain i am 1 location off to the CCW for the leads on the cap and by rotating the distributor CW enough for it to catch the correct lead and allows the engine to fire seems to cement that assumption.

I also stripped the intake manifold down during the re-build to replace hoses etc and send the injectors off for re-build, i am pretty sure i must have moved something, also i bet the fuel pressure is low as the plugs are not overly wet when i pull them, i picked up a tester last night and will give that a go later. Next port of call if that does not yield results is to totally drain one tank and put in a new fuel filter and fuel and see if that helps.

I really think this is a multiple problem issue due to the fact that it's all been messed with during the re-build, it's a case of ticking each component off the list as i go in a methodical fashion.

Thanks for the help so far everyone.

Russell

 

[QUOTE=JagCad;1648989]HMMM, That test light method of setting the static timing is either incorrect or I just don't get the logic from your description.


Carl

The thought process is to measure the pulse back to the Coil/Tachometer, i believe its the only way to statically time an electronic ignition, not quite sure how accurate it is, so it will be calibrated further with a strobe once i can get it running properly.

Russell

 

An update...

I rechecked everything and was simply not happy wth the level of spark from the Petronix. I changed it out for the factory set-up and the spark was a great deal better.

i re-timed everything to the point that i feel confident that it is done correctly.

1 tank completely drained and 5 gallons of fresh fuel in the tank, i then purged the old fuel from the lines and it was amber in color and smelt really awful. Fuel pressure a solid 35psi at the rail and would very gradually drop over time so all good there.

The upshot of all this is no change, the car will start but will not idle worth a darn, it reacts slowly to the throttle pedal and is not linear....

It and i have fallen out, i am going to leave it alone for a while to re-think the strategy...

 

Russell :


Agreed. stepping away for a bit for refreshment nd a rethink makes a lot sense..


I still don't get the logic of "measuring the pulse" to the tach?
It can be "pulsing" perfectly and yet not be at the "right" time. Number one at the firing TDC!!!


But, forget it for a time and then come back refreshed.


Carl