About two months ago I purchased a beautiful 01 British racing green XJ8. A week and a half after driving it it would not start. Nothing. The engine would turn over, but never catch. I had it towed to my mechanic. Initially he though that the throttle body was the problem. He said that he pulled the plugs and there was no start. I sent my throttle body off and had it rebuild by Automotive Scientific Inc, instead of paying upwards of $1200. After putting on the rebuilt throttle body we were still scratching our heads. He checked the compression and it was very low on all cylinders. (30psi average) We figured out that my trying to crank it had flooded the engine and washed the cylinders. We got the compression back up with the oil method (putting an ounce or two through each spark plug hole.) The car fired right up! But it only ran for about five minutes. Then it would crank several other times and just suddenly stall (not gradually.) There is now no spark on the plugs. We have been through all the grounds and messed with some relays. My only concern is that the throttle body makes strange electrical clicking noises. It made these noises before and after the rebuild. Please tell me that someone has an idea. I do not want to pay to have it looked at at the dealer! The compression is still good, but no crank today. I just want my car back for Christmas!

 

Welcome to the forum!

No silver bullet but do you have a Check Engine Light and codes. They would be helpful. I know you said no spark but if no codes I would look next to the fuel system. What is the pressure at the fuel rail? When did you last change the filter?

Pressure should be at 40psi at least.

Let us know.

 

I was thinking "fuel pump" as well.
Whining sound from TB is normal.
(Caused by the little servo motor that moves the butterfly inside.)

 

Okay, thats a relief about the throttle body. Athough I'm pretty sure we have fuel I will run over there and see if I can check the pressure later on today. Does this car have an upper and lower fuel pump, or is that only for supercharged models?

 

One pump in tank on the NA models.
(Next to the battery you'll find the fuel pump relais.)
You could climb inside the trunk, have someone turn on the ignition and listen if you'll hear the in-tank-pump operating.

*edit*
I've attached a picture of the trunk fuse box

 

That goes through the firewall above the wheel well on the passenger side of the engine. Frequently the insulation goes and the car is grounded out and not receiving electricity at the engine...

 

I've got fuel pressure checked at the rail. Does not throw any codes unless running. Currently not. Compression is good ( 130). I'm still stumped. Still no spark. :/

 

bgy08

You say 'it would crank several other times and just suddenly stall' are you saying that when you turn the key to start the engine it starts and runs and then after releasing the key it stops?

If this is the case it may be worth checking your oil pressure switch. If this is faulty your fuel pump will cut out - safety feature in case of accident etc. If the switch is working properly when there is oil pressure it completes an electrical circuit which enables the fuel pump to work when the engine is running.

If it is not working you can make a temporary bridge but I am not recommending you do it or run the car with a bridge for obvious reasons.

 

Addition to my previous post

In general the fuel pump does not work when you turn the ignition on. Only when you engage the starter motor does the fuel pump start. After you release the key when the engine is running does the fuel pump continue to run. If the engine fails to start and you release the key the pump should stop.

 

' . . . does not throw any codes unless running.'

Well, what codes does it throw when running?

Another easy WAG . . . swap the ECM relay for another near by. Center relay in the right firewall extension relay box.

The fuel pump should run for 2-3 seconds when you turn the ignition switch to the 'run' position then stop until the 'start' position.

' . . . got the fuel pressure checked at the rail . . .' Was that a pressure gauge or squirt test? If gauge, what was the reading? If squirt test try with a gauge.

 

Thanks for all the help guys. It was the ignition coil relay that had gone bad. Causing no spark. Took the one for the fog lights and stuck it over there for now. what a relief! running like a dream again.

 

Well done, good find and easy/cheap fix!

 

I would still be interested in what codes were stored.

 

I would be interested where the relay is located?

Anybody have a picture of it's location? DavidN? (Thank you for the previous picture,in my Driver's book,all relays are noted with 1.)

 

I'm with test point on this one. Had a similar problem with one of my cars and after hundreds of dollars and hours troubleshooting it was a 30 dollar relay.