1986 XJ6 no start condition after repaint
#1
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My car spent about 6 months in a body shop being repainted. I drove the car in and it was running fine up until month 2. The shop owner told me te car wont run but this is after they took all of the trim, door handles and hardware so that they could paint it. had the car flat bedded to my house. Battery was dead so I installed a new one yet car wont fire up.
If I leave the car alone for a few hours, I can crank the car get a quick start and if I keep my foot on the pedal it will run, rough but I can keep it running. It will it shut off, and it will not fire up anymore. Ive replaced the cap and rotor, plugs and leads since I needed to and I had the parts ready to go. I know I have spark, and I did get a spray of fuel from the cold start injector. Im at my wits end. Not sure where to look at this point. Any insight?
If I leave the car alone for a few hours, I can crank the car get a quick start and if I keep my foot on the pedal it will run, rough but I can keep it running. It will it shut off, and it will not fire up anymore. Ive replaced the cap and rotor, plugs and leads since I needed to and I had the parts ready to go. I know I have spark, and I did get a spray of fuel from the cold start injector. Im at my wits end. Not sure where to look at this point. Any insight?
Last edited by Brewtech; 08-04-2023 at 01:04 AM.
#2
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Have someone crank the engine while you listen for the injectors clicking.
Also...really easy check here....make sure the duct between the Air Flow Meter and the throttle body is leak free and intact
Make sure the connector to the coolant temp sensor is in good shape and secure. And, actually, just for giggles, remove the connector and jump the two terminals with a small diameter paper clip and try starting the engine. Any change?
There's a white black wire at the "-" coil post that runs aft along the water rail. Make sure it is in good shape
At the rear of the water rail is about a half dozen black ground wires under a bolt. Make sure they clean and secure
Cheers
DD
Also...really easy check here....make sure the duct between the Air Flow Meter and the throttle body is leak free and intact
Make sure the connector to the coolant temp sensor is in good shape and secure. And, actually, just for giggles, remove the connector and jump the two terminals with a small diameter paper clip and try starting the engine. Any change?
There's a white black wire at the "-" coil post that runs aft along the water rail. Make sure it is in good shape
At the rear of the water rail is about a half dozen black ground wires under a bolt. Make sure they clean and secure
Cheers
DD
#3
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I checked the black and white wire and the end is a bit frayed, so will have to replace the end bit of it and add a new spade. Connected the two wires on the temp sensor and the car backfired through the intake yet no start up. The boot on the intake is seated and properly installed. One thing though is Im not hearing the injectors at all, but I did smell some fuel which is probably from the Cold Start Injector. I took my stethoscope and paid close attention to the injectors for ticking or any pulsation, nothing. So this is my problem. How do I get them to do their thing?
Last edited by Brewtech; 08-04-2023 at 01:05 AM.
#4
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First use your test light or meter to check for supply voltage to the injectors. With the key on the injector plugs should have 12v on both wires. If no voltage check the main relay and resistor pack.
To trigger the injectors, the ECU momentarily grounds one of the wires.
The entire fuel injection system grounds with that bundle of wires at the rear of the water rail
If your supply voltage is OK, and grounds are OK, and the aforementioned trigger wire at the coil is OK, we might have to start looking at the ECU...but they almost never fail
Cheers
DD
To trigger the injectors, the ECU momentarily grounds one of the wires.
The entire fuel injection system grounds with that bundle of wires at the rear of the water rail
If your supply voltage is OK, and grounds are OK, and the aforementioned trigger wire at the coil is OK, we might have to start looking at the ECU...but they almost never fail
Cheers
DD
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Mkii250 (08-06-2023)
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The resistor pack was is on RH inner fender, low, and well forward. Almost directly across from the p/s pump. Awkward. Check connections.
The main relay is on the firewall along with the starter relay, fuel pump relay, and the red diode pack. The main relay output wires are brown/slate and should have 12v when the key is on.
Cheers
DD
The main relay is on the firewall along with the starter relay, fuel pump relay, and the red diode pack. The main relay output wires are brown/slate and should have 12v when the key is on.
Cheers
DD
#7
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Thank you. I went to the car a few mins ago. Pulled two injector plugs and they both lit up with my test light. So there is power getting to the injectors. There two wires at the (-) post of the coil that are frayed at the contact point so will have to repair those later tonight. I also have noticed that the fuel pump does make more noise than usual so Im wondering if the pump is toast. I have no ability to check fuel pressure so cant test that. Will remove the main fuel line that feeds the rail and see if Im getting actual fuel to pump through. And will also take a fuel sample to make sure the body shop didnt get water in the tanks at some point. But the sound that the fuel pump is making doesnt sound too good.
Last edited by Brewtech; 08-04-2023 at 10:13 AM.
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#8
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I'm willing to bet the injectors themselves are stuck, you say there is voltage at the injector but is it actually opening and closing. i had a similar situation where i spent some time re-building the engine only to have the injectors stick closed. One way you can determine if they are stuck is to use a 9v battery with extension wires and land 1 wire on 1 terminal of the injector and briefly touch the other wire to the other terminal (do not hold it on just brush it past essentially) and you will either hear click to say the injector is OK or nothing to say they are stuck.
i have heard a technique where you keep applying the 9V (same way of just briefly touching the terminals) to "unstick" a stuck injector, do this at you own risk though. When all 6 of mine were stuck i sent them off for cleaning and re-building and the car ran fine.
i have heard a technique where you keep applying the 9V (same way of just briefly touching the terminals) to "unstick" a stuck injector, do this at you own risk though. When all 6 of mine were stuck i sent them off for cleaning and re-building and the car ran fine.
Last edited by rfarmery; 08-05-2023 at 08:58 AM.
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Brewtech (08-04-2023)
#9
#10
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Another member mentioned checking the ECU to see if it was grounding the injectors correctly (If they pass the "click" test). There is something called a NOID light which will plug into the fuel injection harness and will flash as the ecu grounds the circuit, a great way to test the system.
You can rent the NOID lights from autozone so no need to purchase a set. If I remember there are different sizes in the kit and one did fit just the XJ6 harness
You can rent the NOID lights from autozone so no need to purchase a set. If I remember there are different sizes in the kit and one did fit just the XJ6 harness
Last edited by rfarmery; 08-04-2023 at 04:19 PM.
#11
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I sent my injectors to Jaguar Fuel Injection Service in Florida, I was very impressed with their work and turnaround time.
as mentioned before you "could" try the test multiple times with the 9v battery making sure not to leave the power on for more than a split second as you could potentially burn out the solenoid. I have heard people swearing by it, however I felt if they were gummed up I'd rather have them cleaned professionally and rebuilt to be sure they are tip top.
as mentioned before you "could" try the test multiple times with the 9v battery making sure not to leave the power on for more than a split second as you could potentially burn out the solenoid. I have heard people swearing by it, however I felt if they were gummed up I'd rather have them cleaned professionally and rebuilt to be sure they are tip top.
#15
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Get a noid light (very inexpensive) as mentioned above.
If the light flickers when cranking then you know the injector circuit is working. In that case the lack-of-clicking must be the injector itself.
No flickering from the noid light tells you that the injector circuit isn't working....but does not tell you anything the injector itself.
Life in a body shop is hard on cars. First, the (always ample) paint and sanding dust gets into everything. Second, body shop employees are sometimes a bit um....er...um.....nonchalant in their handling of mechanical and electric "stuff".
Cheers
DD
If the light flickers when cranking then you know the injector circuit is working. In that case the lack-of-clicking must be the injector itself.
No flickering from the noid light tells you that the injector circuit isn't working....but does not tell you anything the injector itself.
Life in a body shop is hard on cars. First, the (always ample) paint and sanding dust gets into everything. Second, body shop employees are sometimes a bit um....er...um.....nonchalant in their handling of mechanical and electric "stuff".
Cheers
DD
#16
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Interesting thing is that if I let the car sit for an hour, I can crank it and it’ll fire up but I have to keep my foot on the gas pedal to keep it running, albeit its not smoothly. Thanks again fellas. I was touching the injector terminals with the 9 volt for no longer than a second, lets hope that I didnt burn one of them out. 😬
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What you should have at the plug, with relay removed, is
White wire: 12v with key on
Brown wire: 12v at all times
Black wire: ground
With the relay plugged-in and the key on you should have 12v at the brown/slate wire
Cheers
DD