Here we have a US 1987 XJ6.
Some history:
Drove to a local car show where it rained all day and my wife drove it back to the gas station to put a few gallons in the left tank. After that it would crank but no start.
Called a tow truck and they brought it home. There it sat for a year before we decided to revive it. I suspected water in the fuel.
So far I have:
Pumped all the fuel out of both tanks, we had hardly any fuel in the left tank and a few gallons with lots of water in the right tank.
Replaced the "pre filters" which I installed previously between each tank and fuel selector and back flushed the main filter. Put fresh gas back in both tanks.
Only to discover the fuel selector was not working (it was stuck), so replaced that. And for peace of mind replaced the fuel pump.
Tested the fuel pressure and circulation, discovered the fuel pressure was high and was not returning back to the left tank, so replaced the valve (it was blocked).
All was well, So now we were ready to start.
Cranked the engine no start, but would fire with "Easy Start". Then managed to keep it running with throttle at 2500 rpm for a minute then it died.
After all that cranking, the battery was now weak so replaced that.
Now, when cranking, she wants to fire and if I manually trigger the cold start injector she will fire but not run.

It did actually run for that exciting minute, so I suspect the timing is ok, although it is still on my check list.
It has fuel because it did run for that minute. I subsequently checked the compression and we have 125 - 150 psi across all cylinders.
So all the basics are covered.
Help please. I suspect the mass airflow sensor or it's connections so that is next on my check list.
Question: Can it run without air filter or must that be installed?
Any suggestions would be helpful.
Thank you
John

 

everybody always blaming the poor AFM for any no start condition.

it could very well be the Start Relay, or the Cold Start Injector, or the Ignition Module, or the Coil, who knows. Or something from the occult or alternate reality like a tripped Inertia Fuel Cutoff Switch.

So start with the last one. the IFCS. Check to see if it tripped like a house electrical service panel breaker, same thing.
Unless you KNOW you have fuel when cranking the engine to start it.
Located on the passenger side above the kick panel, forward of front door, lower corner of dash. A black box bolted to the body with a bunch of wires connected to it at its bottom. At the top of the box there is a Reset Button. press it down to see if it "clicks"… if it did, it was tripped. Car should start now.

If it was not tripped, Next is the Start Relay and someone will show you what to do with it.

NOTE: the reason it ran for that Special Minute is that there was gasoline in the lines, but it took One Minute to consume it and then no more. So I may be wrong but I suspect the IFCS.

 

The Inertia Fuel Cutoff Switch was the first thing I checked.
I managed to pressurize the fuel system after putting gas into the tanks by putting transmission into reverse and turning the key to crank.
But good point and it makes sense that it would run for one glorious minute then die.
Easy thing to do, first.
Then I will look at Start relay.
Thanks.
John

 

check if you can hear the fuel pump charging from the driver's seat.

place shifter in First Gear, turn your ear towards the trunk and turn the key to START position but holding it in START for 5 seconds. Can you hear the pump priming / charging? Good.

repeat this 4 or 5 times holding the key in the START position. shifter in 1.

now place the shifter in P and try to start normally. Nothing? Try it in N. Nothing? This will eliminate the Neutral Safety Switch from being the problem. Or confirm it.

 

The fuel pump circuit has two branches. Start and Run.

The previously discussed method tells you if the pump operates with the key turned to 'start'. But it doesn't tell you if it stays running when the key is released. So.....

Remove the air filter housing and you'll see a flap at the front of the Air Flow Meter. Turn the key 'on' and then press the flap open with your finger. You should hear the fuel pump run. If it doesn't you have a problem with the control circuit.

For testing/experimental purposes the pump control circuit can be easily bypassed. Remove the fuel pump relay. Looking at the connector identify which sockets go to the white wire and the white/green wire. Use a jumper wire to join them together. The control circuit is now bypassed and the pump will run whenever the key is 'on'. You may have two white/green wires. If so, jumper both of them to the white wire.

Cheers
DD

 

Thank you for your suggestions.
Results so far:
With the Air Filter removed.
With the Transmission in REVERSE or FIRST and Key to START
I can hear the fuel pump running.
I did this a couple of times.
With the Transmission in PARK or NEUTRAL and Key to START
Engine fires (coughs) then no fire and no run.

With Key in IGN and open flap on AFM manually:
Fuel pump initially is off,
but as I open the AFM flap slightly fuel pump comes on and stays on all the way to fully open.

PS it is a lot easier to put transmission in "Reverse" than "First", just saying.

So where do I go from here?
Regards,
John

 

Good. That's what you want


Good. The pump is supposed to operate with the flap slightly open...so it sounds like your pump control circuit is OK



You can use "R", "D", "2" or "1". Anything except "P" or "N".

The fuel pump circuit doesn't know what gear you've selected. The idea is simply to power-up the starter circuit without actually spinning the starter....otherwise you wouldn't be able to hear the pump.


Quick idea.

Run a jumper wire from the "+" battery post to the "+" post on the coil. Now try starting. Any change?

More later.

Cheers
DD

 

[QUOTE=jpipe;2458808
PS it is a lot easier to put transmission in "Reverse" than "First", just saying.
So where do I go from here?
Regards, John[/QUOTE]

yeahh but First looks prettier.

check the group of Ground wires at the back end on top of cylinder head, passenger side.

did you do the Start Relay jumping?

 

Doug,
"Quick idea.
Run a jumper wire from the "+" battery post to the "+" post on the coil. Now try starting. Any change?"

As soon as I did that:
Lots of clicking
Battery light came on on dash board
I Pressurized Fuel,
I cranked, no change.
Fired once or twice then nothing.

PS Previously, when cranking, you can hear injectors clicking with stethoscope while cranking.

Thanks
​​​​​​​John

 

Jose,
Ground wires checked and are tight.
Did not jump start relay as I can hear AFM triggering the fuel pump.

PS Previous owner added wires; from back of engine directly to negative battery terminal and they are good too.

John

 

added wires? do you know what they are for?

As if we didn't have enough wires right?

yes I am starting to think the issue is electrical, not fuel. Unless the fuel pressure regulator is dead, and we have seen that recently.

Since you seem to have gone through most everything, I take it your ignition system checks out too? ( wires, cap, rotor, AND MODULE? )

It has to start. Don't give up.

 

The PO detected a ground issue. His "fix" was to extend the grounds at the back of the head on to the - post of the battery. Odd way to do it, but oughta work.

1. The fuel pump is not energized when the igntion switch is in run. I suspect that/

2. The injectors are clogged . they click but do not spray.

3. Any engine run is by ether prime or by the cold start in jnjector

 

"Added Wires":
I am guessing PO had ground problem.

"Fuel Pressure Regulator is Dead":
How should I check this?

"I take it your ignition system checks out too?"
I have not checked timing, but I am getting a good spark at the plug when engine is cranking.

Just a thought:
Previously, It ran for a glorious minute then died.
Could this be running while the cold start injector was on, then when it timed out, the engine died?

Regards
John

 

"1. The fuel pump is not energized when the ignition switch is in run. I suspect that":
I have not put jumpers on the start relay yet. I could do that and see if there is a change in running or change the relay.
I have confirmed the AFM is triggering the pump.

"2. The injectors are clogged . they click but do not spray."
I don't want to take the injectors out and test them, unless I have to.
Are there any alternatives?

"3. Any engine run is by ether prime or by the cold start in injector"
Isn't that the same thing on this engine?

Thank you for your reply. Please excuse my lack of knowledge with this engine.

Regards
John

 

John, most of us work on these cars by trial and error, and by experienced troubleshooting, so no need to apologize. Nothing is chiselled in stone.

Where do the added wires go to from the battery? Worth investigating that.

The cold start injector only injects for a very short time so to test it you need to remove it and watch it to see it working or not, i.e., someone else needs to try and start the engine while you hold the injector AND you might need a new gasket ahead of removing it unless you can slice it off clean.

my XJ sits in storage most of the time with a battery maintainer. Sometimes it doesn't wanna start when it has sat for a long time but I follow the same procedures that I posted here and I get it to start always. I don't see why the injectors would be clogged, and certainly not ALL of them.

Testing the Fuel Pressure Regulator: I 've never had to do it so I don't know but i have read here that the FPR was the cause of another no starting car.

 

OK, no change. This tells us the ignition switch isn't a problem


But now they are not clicking?

Cheers
DD

 

Wiring changes by POs can complicate things. Sometimes hard to figure out what they done or why.

Cheers
DD

 

Speaking of grounds.....

At the rear of the water rail there should be a bundle of ground wires...about six or so. Make sure this ground point is clean and tight


Remove the vacuum hose to the regulator. Any raw fuel dripping out? if so, that condemns the regulator right off the bat. But, lack of dripping fuel doesn't prove that the regulator is good. For that you need to test the fuel pressure. This is checked at the nipple for the cold start injector. Do you have a pressure gauge? When cranking you want to see about 36 psi

Hopefully white/blue spark and not yellow/orange

The timing would have to be wayyyy off to prevent starting.


The cold start injector is operational only when the key is in the 'start' position and, even at sub-freezing temps, will only spray for 5-6 seconds. The spray interval deceases as the temp rises.

Cheers
DD

 

If you have correct fuel pressure and if the injectors click I think the only thing left is that they're clogged.

Cheers
DD

Cheers
DD

 

Lots of things for me to double check.
So as soon as I complete this I will get get back to you.
At last check (two weeks ago) and I see no reason for any change:
Spark was white and strong.
Bundle of ground wires are good.
PO ground wire (located close to these wires to battery neg) was also good.
All injectors were clicking.
No fuel dripping from regulator vacuum hose.
Fuel pressure was 38 psi at cold start injector with new fuel pump installed.

Cheers
John