Hey there,
So ive had a problem with the starter with my 1986 jaguar xj12 VDP and figured my starter was bad because id have to turm it over multiple multiple time for it to kick and start up,everytime i turn the key you here it turn over but its almost as if theres not enough power and the odd time it finds enough power to full turnover and start, but i got an oil chnage last night and left my lights on for only about five minuites and went to start it back up and it wouldnt even turn over the slightest bit, so they hooked up a booster pack and nothing then they hooked up a more powerful one and what do you know it turned over on the first try and started which is weird because i thought i had a bad starter , then they did a testand said it shows its the starter
But then he said since it turned over with all that power on the first try it must not be my starter thats the problem
They said it could be the alternator but there not sure, but im thinking if it was my alternator should my jag just not start every couple days be cause the alternator isnt working but my car only didnt start after 5 minuites of lights being on,
And for the past 2 months it will start on maybe the tenth time i turn the key over,
But if its my alternator shouldnt the battery of died out multiple time in the last couple months,
Please help before i end up taking it to a shop paying that miney just to check it out,and its a brand new battery and they tested it and shows perfectly fine and when i drive the gauge stay at 13 where its supose to be
Please help thanks
,cole
Sorry if sound like i dont know much about cars because i dont i boufht this jag to get me more informed on how engines work and everything because i fell in love with the car when i saw it

 

Tried to explain it the best i can any help is greatly appreciated

Thanks,

 

Oh me. Confusion ++++


But, indeed indicative. High resistance on the cranking circuit
can rob volts from the ignition circuit. Jumping with a "bigger jump box" implies that.


First task, either by DIY or "hired tech. Battery cable clean, tighten and lube. All at each end. + an - on the battery. + on the fire wall post. - on the wing wall.


Then often forgotten and neglected. Down under. Right side. A braided ground cable from the transmission to the chassis.


Results:


1. This works and enough volts are delivered to the starter and ignition and it starts.


2. Not good enough. Too much voltage loss a the starter. Resolve or replace!!


Do these one way or the other, report back and I and/or others will respond as to the next way to go.


Carl

 

So, when you turn the key to 'start" the starter turns the engine...but is lacking gusto? That is, it doesn't turn the engine fast enough?




It is entirely possible that the battery is weak AND the starter is getting worn out. In fact, a dying starter can be very hard on a battery because it (the starter) can draw an abnormally high amount of power from the battery if it (the starter) is on it's last legs


If the alternator was faulty your battery would go dead quickly, yes


It is a new battery?

If so then the starter sounds even more suspect. BUT it is 100% essential to have clean, tight connections at the battery, the grounds, and the starter. If they are not 100% all the testing in the world won't give an accurate result

Poor connections on 30 y/o cars are common

Cheers
DD

 

Thanks for the help i have done what you have said besides the ground cable because i cant get to it atm, but it seems to get the starter to kick up everytime now and start
But when it starts it turns over but takes a bit to start and putters for a few seconds then seems that it gets a enough or something of that sort to fully get running
Im wondering is it just the v12 firing up and they take a few moment to full get going
Or is it possible i have a faulty fuel pump that not enough fuel is getting in quick enough for when its starts up
Id want to ask if its the starter but when i start it ,it starts it turns over but still takes a few second so id want to say the starter is going and weak but once it finally gets the engine going its silent but i can let the key draw back from startung postion and the rpms take a few seconds to go up so now could i have a fuel pump problem?or is this just a v12 and it take s a few moments to get the pistons going

So im assuming since itll turn over but takes a few seconds my starter is probably going now but still wondering about it firing up
And thanks again

,cole

 

[QUOTE=Doug;1506214]So, when you turn the key to 'start" the starter turns the engine...but is lacking gusto? That is, it doesn't turn the engine fast enough?


Id like to thinks your right i did have a cracked terminal on the - and i cleaned most of the points that were suggeated might be the problem amd now it fires but what you have said here seems to be whats happening to now so i thi k my starters going but going to go to a shop and get it looked at now thanks

,cole

 

It may take a few revolutions of the starter to actually start the engine but once started, the engine should run smoothly. No puttering. this could be an ignition problem, fuel delivery or pressure problem, fuel mixture problem.....

Hopefully the repair shop can zero-in on the problem

Cheers
DD

 

Appreciate the replys, info was much needed and helped
Thanks again and im thinking its a fuel pressure problem but guess time to take it to a shop
Thanks again from over here in canada

,cole

 

Dieter: the proper cold starting method for the V12 is to turn the ignition on, listen for the fuel pump to run for 3 seconds, at which point the pump will stop automatically, and then and only then you turn the key further to engage the starter. If you do not use this procedure you do not have enough fuel in the fuel rail to allow the engine to fire quickly.

 

Gregory, too bad about that XJ12 we' ve talked about... That would have been a cool one. And thanks again for your info .
You are a true gent.
Terry