I’ve got spark, and I’ve got fuel, but the car isn’t running. Normally I’d think next thing is timing, but you can’t time a Marelli. That leaves air or stupidity on my part.
The following is known:
Fuel pressure is 38 psi, measured from a T on the pump side of the under hood fuel line.
The injectors are abolsutely positively firing when cranking, confirmed electrically with noid lights, and audibly with a automotive stethoscope. The injectors themselves were cleaned by Jaguar Fuel Injector Service one year ago but not used since. They click well, but I cannot see the spray obviously.
The distributor body is correctly aligned with the center rib of the valley pan. The distributor body has not been removed since the car was last running.
Every cylinder is known to be firing well, except B1 and A1 which I did remove to verify good blue spark.
A very good used engine harness was just installed from a running 92 wreck with 31k miles. This solved a no ignition signal to fuel ecu problem, manifested in no ground signal to injectors. It was cheap, but I have nice working injector electronics now,
The following is not known:
I unjammed and rebuilt the AAV. I have the large screw in with three thread showing. I’ve tried starting car with this full in, full out, and three threads out. Can a massively misadjusted AAV weaken the mixture enough to prevent starting?
I found the previous owner really got the throttle plate assembly wrong. Basically the right side couldn’t open enough because the ear and tang on the throttle shaft where not in each other. I then went through the entire throttle setting per Kirby’s book, but maybe I f’d it up. Is there any possible throttle set up you could do wrong enough to stop the car from starting? With foot off the pedal, the plates are closed with the correct clearance.
Anyway I could go on and on confirming what I think is good. I’ve got fuel, I’ve got spark, the car WANTS to start and fires maybe a cylinders here or there. WTF do I look at next? And remember it could be anything because this engine bay was disassembled well down, cam covers off.
John,
You need to review my posts from last year when I had tge same problem with my wife’s 1990 XJ-S convertible with Marelli ignition. It would not start following my engine bay cleanup. I sent my fuel injectors out for service and let them sit for about 3 months before installing them and 11 out of 12 were clogged. I verified this by removing the fuel rail and testing it with pressurized air while hooked up to the harness. I posted a bunch of times when I had the no start, when I discovered the clogged fuel injectors and my successful start after getting the re-serviced fuel injectors back. It sure sounds like you are experiencing the same thing that I did.
Hi Paul- I will re-read your experience on this topic. When your injectors were not working, were they clicking? I had a few that stopped clicking from sitting and I had to put in an ultrasonic cleaner with the pulse generator on, but they started clicking again. I’ve also confirmed they were clicking ALL clicking when cranking. There’s a faint click (nearby injector) and a loud click (this injector clicking) so I can discern between adjacent injectors. Let me know about your click experience!
If you get a lusty response that sounds like you expect with your foot down for a normal start, that tells you:
The ignition gives good spark.
Timing is in the ball park.
You have plenty of air in the engine.
To get the engine running you need the correct fuel pressure plus:
Pulses to the ECU to let it know the engine RPM.
That from the flywheel sensor ?
Pulses from the crankshaft sensor for injector sequence initiation ?
( I do not have a Marelli car so hope that info is correct )
TPS signal to the ECU to say the throttle is now open for business.
Vacuum connecion to the ECU so it knows which part of the fuel map is operative.
Coolant temperature signal ( very critical ).
Air temperaure signal ( not so critical ).
If the ECU computes the correct injector firing sequence and duration from the inputs. you should have just the right amount of fuel to start the engine.
I took a chance (and a fire extinguisher) and pulled half the injectors up. They were all wet to the touch on the pintle end. I put the pulse generator on one and gave it a spray. Turned the key to charge up the fuel pressure again and took a video:
Starting fluid… unexpectedly, nothing happened. I’d have thought it would have fired at least momentarily or maybe stumbled a bit. Not much of anything with starting fluid. Sounds like ignition now…
So, massively wrong timing (i.e. rotor nowhere near pointing forward with engine at TDC)? But wouldn’t the starting fluid make timing roughly irrelevant? I’d have thought I’d get a rough fire or some back firing or something like there was a spark.
So I’ve deluded myself about the spark, or the spark was good and now I’ve rustled sometime fragile and now it’s not good? Guess it’s time to check it again.
On some of Richards notes…
Pulse from ECU is good because injectors are firing, and fuel pump is restarting when cranking.
TPS is “calibrated”. I was getting FF17, but I set the TPS for .37 volts with throttle closed. FF17 went away.
Vac to ECU hasn’t been measured. I guess I should, but it has a new clamp on engine side
Coolant temp… I did get FF15 VERY briefly but it’s gone. That’s not timing side anyway.
John,
It sounds like you have one of those aftermarket Marelli caps. The OEM Marelli caps have those two coil posts identified with “A” and “B” cast into the plastic. Please see the attached picture. The tall center post is for the “A” coil and the lower off center post is for the “B” coil.
When I encountered the clogged fuel injectors after they were serviced last year I could hear someofb th hem clicking, but I could not hear most of them clicking. When I asked the company that service them for me about the post service shelf life they told me that they expected the customer to install them within 30 days, otherwise they might get stuck. My injectors sat about 3 months after they owe re serviced before I installed them and 11 out of 12 were stuck. You said that your injectors sat for about a year after being serviced, four times as long as mine. I believe that you used the same place in FL to serice your fuel injectors.
The only time I had a non starting problem with a V12 was loss of compression. Dropped valves probably due to overhearing some months before. It was quite sudden.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
11
Another possibility, I guess, is that the key on the crank pulley has sheared. This would move the timing around to someplace random.
Kirby, that might be a good guess. Not so much sheared, but I replaced the front main seal so there’s a fair chance I left one or both of Woodruff keys out.
A friend here in the San Diego area had a problem with his 1990 XJ-S convertible several years ago where the internal engine gear that drives the distributor was damaged and the so the timing was off. As I recall the repair was expensive and time consuming but eventually successful.
Took the damper off and found all both keys in place. Forgot how not fun that was to do without removing the radiator.
Anyway, I thought the cone should sit a little better in the damper… and thought maybe it was hanging on a crooked key, but even with it out it still sits not flush:
But… notice the big A! (I whitened it up). Does this mean I can time it anyway just as a sanity check (to rule out a stripped gear like Paul mentioned)? How nice of Jaguar to include that marker and then hide it behind a huge additional piece for the rest of the belts.
My next steps… reassemble mostly, run a timing light assuming the A would appear approximately where it did on Lucas CEI cars, then lay all the plugs on the manifold and recheck for a lovely blue spark… and if that doesn’t work I’m mailing the injectors back to Florida for a double check!
John,
Sorry but I can’t answer your damper questions.
However, you might want to do a test that I did before and after sending my serviced fuel injectors back for a reservice to check the fuel injectors out. I removed the fuel injector rail from the car disconnecting the fuel lines but then reconnected the fuel injector electrical harness to the fuel injectors. Then I connected my shop compressor (about 35 psi of air pressure instead of fuel) to the fuel rail and had my lovely assistant crank the engine while I monitored the fuel injectors. When I first did this, after encountering the stuck fuel injectors, I could hear just a small number of the fuel injectors clicking and I could feel a burst of compressed air from the small number of injectors that were working ( just 1 or 2). That test convinced me that my fuel injectors were stuck after sitting for 3 months but that everything else was probably working right. After I received the reseviced fuel injector rail back, I ran the same test and all the fuel injectors were now happily clicking away and spraying compressed air sequentially in groups as they should. It was at this point I knew that I had identified the “no start” cause as stuck serviced fuel injectors and that it was now fixed. The remainder of the reassembly process was uneventful and the engine started and ran very nicely as expected. Much to my pleasure because I thought that I had made an error in my work especially in rebuilding the EFI harnesses. Little did I realize that serviced fuel injectors had a 30 day shelf life and that by getting the fuel injectors serviced at the beginning of my engine bay cleanup effort, instead of at the end, I inadvertently caused myself considerable extra work and expense. I will never do that again.
I am a bit puzzled about the injector shelf life issue.
What are they putting into the injectors before sending them, or what are they not putting into them that they should ?
New cars leave factories with maybe 5L of fuel, just enough to get them around a ship or dealer parking lot. Perhaps that 5L also includes a good dose of an additive. Then they may sit there for anything up to a year before being sold. I doubt they are always driven every few months, so do the injectors often need removal for service before the car is sold ?
By the way John, I did not see anything in your posts to suggest you did a basic timing test before pulling out the damper. Did I miss something ?
New car injectors are installed on a car, and there is not alot of air near the injectors. Rebuilt injectors in a Ziploc bag however? If you order new injectors they often are in hermetically sealed baggies, or even those electrostatic discharge type electronics bags, but these were not. Also at the place I used, a now discontinued practice was to squirt the injectors with WD-40, and it’s been suggested the WD-40 formula has changed causing the problem.
Anyway no I haven’t checked the timing, because it’s a Marelli car and I always thought you can’t. It wasn’t till the damper was off the car that I saw that marking.
I’m going to have to do exactly what Paul describes, with air. And everything else. I’m really tired of this car sitting around garage.
Richard,
I was a bit more than puzzled when I experienced this shelf life issue with my fuel injectors. I’d have to say that I was absolutely astonished to find out about it, especially after troubleshooting pretty much everything else in the engine bay when I had the no start problem. I rebuilt the fuel injector harnesses with a lot of new and nice used connectors as well as changing out a bunch of components, adjusting the intake and exhaust valves, installing NOS OEM Marelli cap and rotor, etc. So I suspected that I had made an error somewhere when the engine didn’t start. The fuel injector rail with all the injectors had recently been professionally serviced so they were the last thing I considered after removing, testing, and reinstalling pretty much everything else at the top, front and sides of the engine. After my experience the owner of the shop added info on his website that the injectors should be installed within 90 days of servicing othewise the pintles might get stuck. That is evidently what happened to mine while the fuel rail with the injectors connected sat in the shipping box in my garage for maybe 5 months while I completed other work on the car.
I was told that they use a few different products to prepare the injectors for shipping back to the customer including WD40. And that post-service shelf life and stuck fuel injectors are a recognized issues in the fuel injector service industry.
There was mention a while ago WD40 could cause corrosion. Not sure if that is tue or not, I prefer to use an Australian made product instead, it seems to have more lubricity.
I suspect the cleaning brigade should talk to the injector manufacturers. For sure they will have a recommended treatment to give many years of shelf life.
I have an ultrasonic cleaner in the factory and clean my own injectors if needed. There is a set of 12 brand new Bosch injectors in storage the last 3 years which will eventually be fitted direct to an extruded alloy fuel rail. They have plastic caps to seal both ends. I bet they work first time they are used.
