QuestionQUESTION: Hello Mr. Fitzcharles III,
Thank you for being here. I have read many of your responses and was hoping not to haveto ask. I have several xj6's I want to get on the road but my first one was running fine til this years snow in New Jersey when I parked it in the back and it was buried in snow for a while. I had recently purchased it in oct. replaced fuel pump because it went on me. All sparks plugs, rotor, cap and wires were replaced. Started instantly and ran very well. After sitting I had a hard time starting and drove it around the block. Shut it off at home but when I went to start it later it would not start. Well more snow came and I did not get to it but when I did it was a warm day and started right up but ran for a about 3- 5 seconds then shut off. Tried again and no start. Waited a few hours and it did the same. This is what it is still doing.
No sputerring or coughing. Reeved it up but it still just dies.
-I put a charger on the battery with 50 amp now to give it alot of juice and the same thing.
- checked spark with timing light. good til dies.
- Jumped fuel pump at white/green wire and pump ran with 40psi on pressure gage.
- changed fuel filter.
- used noid lights to test all injectors. They were good.
- put in more fresh gas and some heet to diminish possible water.
How do I test the fuel pump relay. With it plugged in and just touch the plugs to test the the terminal voltage? Do I need a volt metor?
The Afm flaps open when it starts.
I have down alot of repairs on my jags but mostly hardware. No electrical or complicated starting problems till now.
Only other thing I observed is when I start the car with the key I get no fuel pressure reading. It was only when I used a wire from battery to green/white wire at the fuel pump relay connector.
Also it runs a tad bit longer when it is warm. But I still have to wait about two hours to try again. Testing has been drawn out.
Appreciate the help
How do I test the brown/gray wire for the afm. At the starter relay or what? Do I stick it up in the connector or what?.
If I can under stand this it will help alot in getting the others to start and run. Hopefully
Catherine ( a jag lover)
ANSWER: Hi Catherine,
I found that "symptoms" of a problem can sometimes lead you to an area but for the most part are useless in diagnoses. Testing is the only sure method.
All gasoline engines operate the same and only need three items to run. Compression, Fire and Fuel with conditions on each. When an engine dies, it has lost one or more of the 3 items.
If you brought me your car and told me all that has happened I would have to start from scratch by first running a compression test (throttle open) to be sure the engine combustion chamber was ok. Only then would I proceed to "Fire" (ignition) Your timing light test is a good one IF you did it correctly. You MUST see the flash of the timing light on to the last revolution when it dies to be sure the ignition is not what killed it. Sometimes I have to quickly rev the engine up so I can see the timing light flashes all the way to the last rotation of the crankshaft even after the engine dies. This tells you that it had ignition all the way to a stop.
Fuel must be last on the testing. First turn the ignition key to "ON" not start. take the air filter can off and open the AFM flap manually and you should hear the pump start running. This only establishes that the pump system is on and working as it should. If you have a fuel pressure gauge on the fuel line going to the fuel rail using a "T" fitting thus allowing the pressure regulator to operate and you get 40+ PSI it is ok on pressure. Then you should apply vacuum to the regulator and watch the fuel pressure. It should not drop much lower then 32 PSI. This establishes that the fuel pressure system is ok (other then volume).
Next take a can of starting fluid and start the engine and keep giving it a shot of starter fluid to see if you can keep it running on starter fluid. If you can keep it running on starter fluid and it will not run on it's own, you for sure have a fuel injection problem and if you still have the pressure gauge on with a "T" in the line so that it is receiving fuel pressure then you have an injection failure.
If this is the case, you first should connect up a known good battery as a jumper battery (like when you jump start a car) even though the battery in the car is charged up. This gives you two good batteries connected in parallel. If the engine then runs, you need a new "Deep Charge" battery (diesel or marine) The series III Jag requires a deep charge battery to operate.
let me know what you come up with.
Howard
---------- FOLLOW-UP ----------
QUESTION: Thankyou again Howard,
Ok recap of test.
With key on then open AFM flap:
only get click sound at relay but pump did not run. And no fuel presure.
-When car starts on own an runs 5 sec - no fuel pressure.
-When car restarted on starting fluid. - no fuel pressure.
-When car was kept running on starting fluid -no fuel pressure.
-When fuel pump jumped at relay connector - pump runs and presure 40psi.
Was unable to redo timing light test because bulb blew. Its on order. Original two test with timing light showed spark til shut off. Is there another way to make that test?
Was starting compression test today but could not get spark plug back into the hole on no. 1 . It was 150lbs. I was hesitant to put the gage in my next hole until I can be sure it was not the compression gage threads that messed up mine. Should I use a thread chaser to solve that problem. Even tried a new spark plug but would not go in. Don't want to buy any thing with out some advise.
Well its obvious its not getting fuel. What should I check next in that area. The fuel filter is new and pump operates when jumped. I will attempt to finish the compression test but thought I could check in and get advise on addressing the no fuel problem.
recap- All injectors flashed with noid light.
How is it the car starts and runs while not receiving fuel?.
How do I apply vaccum to the regulator?
I am using a battery charger with the jump start feature at 50 amps. Is that as good as another battery?. Its the plug into 110 in the house type.
Thank you again
Catherine
ANSWER: Hi Catherine,
I found that it is best when doing several tests on a car, if you run into a failed test, you need to correct that before bothering with any other tests. You found a "No fuel pressure" when opening the AFM flap with the key on and you jumped power to the fuel pump and it ran and you heard a "Click" when opening the AFM flap so this indicates a failed relay. Now you need to test the relay.
All relays are numbered or lettered. The fuel pump is numbered.
#30/51 is power
#85 and 86 are the electric magnet in the relay.
#87 is out-put to the load (pump)
You said you jumped power to the pump at the socket so that means you put power to #87 in the socket (not always numbered but the relay is)(some relays have two #87s)
This means you have tested the pump circuit from the relay socket to the pump and the pump itself.
Next test is the socket of pin #85. Power the clip of a 12v test light and probe the socket of pin #85. It must be a good ground.
Next test is the socket of pin #86. Ground the clip of your 12v test light and probe the socket of pin #86. Your test light should light when you turn on the ign key and open the AFM flap. (this is a test of the AFM switch, the diode pack (red relay) and the circuit to the pump relay.)
Next test the socket of pin #30/51. Ground your clip of your 12v test light and probe the socket of pin #30/51 and the light should light. (key on)
This tests the car. Now you need to test the relay itself.
You need a 12v test light and a couple of test leads and a 12v battery.
Connect a test lead from battery (+) to pin #30/51 and a short jumper to pin #86 so both are powered. Connect your 12v test light clip to the battery (-). There should be no light.
Then connect another jumper from the battery (-) and take the end of that test lead and just touch pin #85. You should hear a "Click" and the test light MUST light up.
This is a test of the relay. (all relays too) except those British relays that use letters instead of numbers.
A Jag cylinder head is very expensive and it can be very expensive to correct a cross threaded spark plug hole so if you have not used a plug tap or a thread chaser very much you should get someone with a lot of experience to correct the threads in the spark plug hole. A thread chaser or a tap can do a lot of damage attempting to correct a minor thread damage. I have had many different cars brought to me after someone tried to correct a minor thread damage and they did major damage that required the head be removed to correct the problem or a tap being needed. A small light and a magnifying glass will sometimes tell you what needs to be done.
If you decide to use a thread chaser be 100% sure it is held perfectly straight with the hole. A thread chaser with a long taper will help keep it straight.
Before you attempt to use a thread chaser put the piston at TDC of the compression stroke and tare a small piece of rag off and stuff it all the way into the combustion chamber and then pump several pumps of a grease gun into the hole on the rag. Then you can use the thread chaser and when you are finished, take a coat hanger or welding rod and bend a small hook on the end and fish out the rag. The grease will catch most all of the aluminum cuttings and the rag will pull most of the grease out. Take another rag and rotate it in the threads to pick up as much of the grease as possible. If you don't do this, some of the aluminum filings can get trapped between a valve and it's seat and get stuck there and burn a valve very soon.
Howard
---------- FOLLOW-UP ----------
QUESTION: Catherine here,
Some how I lost the last answer you gave. But here we go. I had did the circut tests and it was the fuel pump relay. While waiting for a shipment I decided to try my knew knowledge on the other two xj6's I want to get on the road. I discovered the relay on my 87 was bad and the fuel pump on my 84. I got the 87 running. Still not getting fuel on the 84 after changing the pump and filter. So I will trouble shoot my fuel line some more. The 87 is running really rough and won't stay running if I take foot off excellerator. However, I discovered a fuel leak. So I will tend to that. I am going to invest in a fuel injection cleaner. Since I have so many I figured I might as well learn to clean my own.
Well finally I was able to get a mechanic to come over and chase the spark plug hole on the 85. With a new relay it started right up and is running great.
Thank you so much for the education and sharing your expertise. I will probably read some other posts if I get stuck on other issues. Hopefully, I will be able to get them all ship shape.
Thanks again
Catherine
AnswerHi Catherine,
Glad to help. I see you suffer from the same disorder as I do. Too many jaguars. They are cats you know, so if you leave them outside they will attract other Jaguars. That's how I explain mine.
I have a web site that is mainly automotive (British cars) and several tech tips that may be useful. http://mg-tri-jag.net
Howard
