My name is Anthony and I'm brand new to this awesome forum! I am very excited to be posting my 1st thread! First of all, I LOVE my Jaguar (89 Vanden Plas) but could really use some help with a VERY frustrating problem I've been trying to solve for the past 6 months: STALLING and then not being able to start back up very easily and sometimes not at all.

The car will run perfectly one day, and then the next day (mostly in the morning) will either not start or if it does start, it will run for a minute and then stumble a couple of times and then die. At this point it may or may not start back up. If it doesn't start, I usually unplug the air flow meter and can get it to start. I'll let it run until it seems stable then plug the meter back in (engine RPM usually goes down when I do this). I tried replacing the air flow meter with another one from a junk yard but the car does the same thing. I have since replaced the fuel pump, fuel filter, coil and coil wire but car is still doing the same thing. One mechanic suggested I replace the air meter with a NEW meter but I hate to do this as just something to "try" at a $300. price tag.

I'ts strange. The car could run perfect one day, then give me great grief the next day?? Do air meters work and then not work?

Any suggestions would be GREATLY appreciated!!
Thanks,

 

Three thoughts that I have...

1. Have you tried jiggling the gear selector when having starting issues?
2. Have you checked and cleaned the Throttle Position Sensor (TPS)
3. Could it be a faulty Oxygen (O2) sensor

and I just thought of a two more...

4. Have you checked and cleaned the Idle Air Control Valve
5. Have you checked the Exhaust Gas Recirculation (EGR) system?

Chapter 6 of the Haynes Manual covers most of the checks you (or a knowledgeable mechanic) can make to these components

 

Hi Anthony. Welcome.

I posted the following a while back. You might want to take a look at it.

Testing the XJ40's Air Flow meter
Trick Freestones

 

Thank you both very much for your replies!

Re comments from JAGFIX38, I know the gear jiggling you are talking about. I believe that is the Inhibitor switch which was the 1st problem I delt with on this car. I had to jump the starter relay for a while until I did the jiggle thing enough times where it somehow worked itself out and I no longer have that problem. Also, the car won't crank at all when that is not working. With my current mystery, the car cranks like crazy but just won't start...until i get out and unplug the air flow meter. Then it will start (most of the time). It will seem to idle fine (a bit high though) with the air meter unplugged, but if I try to drive it the car will stumble and die in after driving a block or two.

I have not checked the TPS, EGR or O2 sensors yet but wouldn't they cause an error code or check engine light? I have no codes! (at least I don't think) The haynes manual mentions that 88 and 89 cars don't have long term memory and you have to check the codes when you first turn the car off ...but you must make sure you don't turn the key all the way off, only one position back, then check the codes. I do this and still no codes. (except the various usual ones I have always had like: low brake pressure, circuit 1,2, and 3 failure, coolant low, wiper something,). I will check chapter 6 of the manual to see how to test those sensors anyway.

Re comments from Trick, thank you for your "welcome"!

As far as running condition, I go from it running perfect one day to having big problems the next day. On a problem day ( which is like 3 times a week), the car usually starts up fine and runs for about a minute or two perfectly. Then, it all of a sudden starts to stumble a bit and stalls out. Most of the time it won't start again until I get out and unplug the air meter. I will get a check engine light because the air meter is unplugged but it goes away when I plug it back in. Once I plug it back in, I can usually limp it to work ( I have to put it in Neutral and keep it going at the stop lights) . Other times, I can't even get it down my street. On those days, I usually limp it back home and get my lecture from my wife about why is this car so unreliable!

I would love to "test" the air meter more conclusively but the manual only gives two simple voltage tests that I don't know would be conclusive if it is working intermittently. I wonder if there are any other tests besides testing voltatge on terminals 5 and 3 as the Haynes manual describes.

 

Just from experience, check for blocked air filter, cruddy or split bellows, and throttle body, have a look at your distributor cap.

Oh and yeah, next visit to the scrapyard, borrow a couple of extra MAFs. The guys have always said yes to me, when I ask. (usually they are amazed that I want to borrow for testing and return the bits I don't require). Honesty works.

 

Very interesting. I would have never thought to ask a scrap yard to borrow something! You're right though, doesn't hurt to ask!

Today I'm now thinking it is not the air flow meter because I got in to go to work, the car started up and ran for about 20 seconds. Then it started to stumble and I kept it going by just giving it gas. After about a minute, it stalled in spite of my attempts to keep it going. Then I could not start it so I got out, unplugged the air flow meter and tried to to start again. This usually works but today it did not. Could not get it started - had to eventually take a different car to work ( of course my wife came and kids came out to ask me why I was still home and why the car didn't work (again)...sigh....

 

Have had similar issues albeit on another make of car and the tdc or crankshaft sensor seems to be the culprit?

 

Interesting you say that. I've been suspiscious of the crank sensor myself. I need to check on how to test that and see how much a new one costs (and how hard it is to install).

Just to update from my no start condition yesterday morning. Of course, when I got home last night it started perfectly and I drove it to the store with no problem. This is looking like mostly a morning issue??

 

If its a morning issue, you might have a grounding problem (as overnight condensation gets between the screw or bolt and a slight bit of corrosion occurs and weakens the ground). There are many grounds on a jag.

 

As per Lumpy - I know it sounds basic almost but earth connections are important and all too often overlooked and could be a good call.

One of the Clios suffered from the tdc crankshaft sensor issue, the other also had intermittent start issues and loss of power.....a thourough going over of all electrical connections and battery terminals / connections seemed to resolve this around 2 months ago and haven't had an issue since.
Prior to that the car had the issues 4 times over 3 days and for 3 days in a row.

 

When I say morning issue, it may be more "1st drive of the day", which is typically in the morning. Now this has been happening around 9am in the summer here in San Diego so it is pretty warm. I did also have the problem on a "second" drive of the day (around 3pm) so it is not always morning.

That all being said, I have cleaned and wire brushed all the battery connections, grounding straps to the firewall, all of the ignition coil connections. I know there are a bunch more grounds you guys are talking about, can you let me know which other ones that are the more important ones?

Thanks again guys!

 

I would recomed getting a haynes manual,as it has lots of useful informtion. They are not expensive (e bay ,craigslist etc).It will tell you where most components are and how to repair. Much cheaper than paying a mechanic.

 

I did pick up a Haynes manual and this will be very helpful!

Some potential VERY good news.... and I don't want to count my chickens before they hatch but so far so good. Last night I changed out most of the secondary ignition stuff (rotor, cap, and wires). These were not new as I got them from the junk yard but I sanded and cleaned all of the connections up nicely. Also, my distributor shaft was totally rusted so I sanded that all up as well. When I went to start the car, I can sware I barely even touched the key and the car started up instantly! Then, the needle on the tach was sold as a rock!

This morning, the car started up the same way and drove perfectly to work! Again, I don't want to get too excited, but if the car works on Monday morning I will be feeling great and if it works for a whole week I will declare this solved! It these simple parts fixes the problem I will kill myself for not trying them 6 months ago but I just didn't think (since when it did run, it seemed to run fine) that these parts could cause the symptoms I was having. Anyway, I will keep you guys posted to let you know how it works out!

 

I just wanted to let you guys know that the car started up perfectly ON A MONDAY!! Like I said on Friday, I don't want to count my chickens yet until the end of this week....but this is looking good!

 

congrats on getting her fixed! im having the exact same issues will try what u did this coming weekend thanks for the post hopefully it will solve mine too.

 

Ok, today is Tuesday and the car has worked perfectly again today. Now that is 5 days in a row without stalling and no-start condition!

Believe me I'm still amazed that a rotor, distributor cap, and plug wires (or I guess it could have been any one of those) could have caused this hair-pulling problem for me for the past 6 months. Do you know how many intersections I got stuck in the middle off ....I think at least 25% of my gray hair is from this!

What really threw me off on this was that the car actually ran pretty well when it was not doing it's stalling or not starting thing. Had it ran poorly all the time, I would have changed these components right from the start.
Now I know these secondary ignition parts are capable of having these symptoms. I'm sure glad I finally tried this simple and relitively inexpensive thing first before I bought the new air flow meter for $300.(which I almost did!)

 

Oh, by the way, for the guy who is having the same symptoms...It would be GREAT if someone else could benefit from this fandango......good luck and let us know what happens!

 

Looks like you've got it cracked AJ, hope it continues to behave.

 

Nice one AJ....I'll be keeping my fingers crossed for you but it looks like you have it sorted.

Please feel free to come back in a week or so and post that it is fixed for sure.....We can then add a "FIXED" onto the thread title for future users.

With the above in mind though....I'd suggest that we will ned to change the title somewhat as its unlikely to get too many hits with its current one when people are looking for non start issues on their Jag

 

Great idea Jim!

Today was another good day but I would like to wait a couple more days before I give it my full blessing. At that point, you are totally right about changing the title ....just will need to figure out how to do that??