I got a few codes telling me I had random misfires so I bought new spark plugs, coil packs, intake manifolds etc and swapped all the parts. The car has 112,000 miles on it. This is the first "tune up". Car has run flawlessly up until now.

After installing all parts with no real problems I re-start the car and it idles rough like a spark plug wire is off a small block Chevy. lol. While the car was running I unplugged the coil packs one at a time to see if there was a coil pack not firing. Each time I unplugged a coil pack the engine ran worse. The only one I couldn't check was the rear one on the passenger side under the rear of the intake manifold. I'd have to remove the intake again to check it. Grrrrrrr. I'm assuming all the coil packs are OK for now.

Next I checked for wires loose in the pig tails going to the plugs that attach to the coil packs. I jiggled all the wires and nothing changed. They seem OK.

Next I checked for a vacuum leak and found the rubber hose on the end of the plastic tube coming from the vent on the drivers side valve cover had a huge hole in the bottom of it like it had burned through. I replaced this 3" long rubber hose with a piece of hose found in my garage. This didn't help anything.

I'm at a loss what to do next? When I drive the car it will only go to about 3000 RPM's then a rev limiter kicks in and it feels like the fuel is being shut off for a second over and over. The car jerks until I let off the throttle and the RPM's go below 3000 RPM's. As long as I keep the car under 3000 RPM's it will run but you can feel the mis-firing as it now vibrates the gear shift (5 sp. manual).

My dash reads RESTRICTED PERFORMANCE at all times. The yellow engine light in the shape of an engine is flashing. The local Advance Auto Parts will read the codes but will not clear the codes for me. Does anybody have any ideas what could be wrong?

One other thing........I bought upper and lower intake manifold gaskets but only used the lower ones that go on top of the engine that the intake manifold sits down in. There were six of them. They were 3-4" long and had rounded ends. I couldn't find any other intake manifold gaskets on the intake or anywhere to put them. I didn't open the box to look at the new ones because the box says I can't return them if they are opened. Grrrrrr.
Could this be the problem? Where do these upper gaskets go? Anybody have a link to a diagram?

Thanks in advance.

 

You say codes but what are they?

Fixing a bad hose like tht should make a big difference so if it didn't do that then could it still be leaking (even if only a little)? Any leak at all will cause problems.

You can check for air leaks using OBD live data. Look at fuel trims at idle & at 2500rpm.

Flashing MIL = very bad news as it's catalyst-damaging misfires i.e. the very worst kind

 

Please post the code numbers, as stated above.

 

EZRider, your original and current issue "was" likely a vaccume leak caused by the burnt through vaccume line. You repaired this item but the ECU is recycling the code, thus restricted performance (RP). As a means to protect the motor from a too lean condition, the ECU will not allow operation beyond 3000 RPM by cutting off fuel at this juncture. You either must reset the ECU with a tool or perform your own hard re-set of the ECU by disconnecting the negative wire off the battery negative terminal, touch it to the positive terminal for 30 seconds. Before undertaking this do as Rick and jagv8 suggest: read the codes, then perform a hard re-set of the ECU as outlined. You'll likely see smooth performance, but if an issue remains, she'll again shoot of a CEL w/RP.

 

No!!!!!!

You do NOT need to reset the codes.

But do read them as you do NOT want to lose them.

The PCM will auto-reset them if/when the underlying problem is fixed.

If you reset them, or worse if you disconnect the battery, you can get a car with no codes because it now cannot work out what to do with the state it's in. Why take that risk?

 

Thanks for the replys guys. I need to find somebody with a tool to read the codes as I do not have one myself. I'll post the codes as soon as I have them.

Anybody want to answer the question about the intake manifold gaskets I didn't use? Where do they go? See last paragraph of first post for explanation.

Thanks!

 

Retort: "Yes"!!! I mentioned read the codes prior to re-set, not re-set then read codes. Don't worry about losing codes, they'll reappear if you should re-set but a problem persists, etc, "been there, done that". They'll even be there even if you should nail the problem. You can either trust me and move on, or stew in the perpetual land of "Code-Um", whilst your original issue has been resolved. Unfortunately our Jags don't always have the inherent wisdom to "immediately" re-set the ECU and clear codes following the resolution of a vaccume leak....Been there- Done that... just two weeks ago...a Jag tech work on her for vaccume line leaks, plugs, cam cover, supercharger, throttle body gaskets (be sure to check brake vaccume line attaching it to the intake manifold, this is a weak design), etc. A vaccume line failed, sucking in huge quantities of air, leaned her out.... Following the repair the codes and CEL w/RP reappeared. It took over two weeks for the ECU to clear an already resolved issue. I don't know why and nor does Jag understand why...A complicated or foolish program for these pre (FORD influenced) now TA TA Motors (Jags present owner) cars? How many Jag stories have we heard where Jag/ tech/owner repairs an issue, clears the code then the cars back in the shop several times before mysterious forces eventually clears the code? Regardless, read the codes, clear the ECU. Don't worry, if the issue isn't resolved, the identical codes will reappear. The Jag's ECU has adaptive learning. Periodic hard re-sets help purge old- sluggish driving styles, to be replaced by drivers imput. Take my advice for what its worth. Just my two cents based upon mine and likely thousands of Jag owners who became surprised by the results based upon what I outlined.

 

As I keep saying, that only usually occurs. You will be VERY sorry if you're the exception. Plenty of very sad tales from those who've found out the hard way. Besides, flashing MIL / rough running means it's not fixed. Use OBD live data.

(The basic idea of OBD is find the codes and/or use live data, fix the fault, recheck any live data. Possibly clear the codes, but only after you have a fix done and for a reason. Battery disconnect on appropriate cars, again if there's a good reason such as making a relearn occur. Not to be done to "see what happens". Especially don't do it when you know the car's not fixed.)

 

Ok in the first picture the six yellow gaskets are upper "plenum" gaskets/seals also known as upper intake gaskets/seals



Now in the second picture (below) the 6 blue gaskets/seals are the lower intake. After the removal of the plenum (upper intake) there are 4 more bolts to remove the lower intake.



Look at the seal pictures closley, the upper (yellow) are different than the lowers (blue).

Hope this helps!

 

Hey, great pics!

 

Hey, did any of you guys see "Battleship"? It just came out in movie theaters and I saw it Saturday. Ricks hand in the pics looks similar to that of the aliens...like a caucasion ape hand. Just thought it interesting, sorry. IMO a crappy movie. Saw it cause my neighbor is Liam Neeson (Millbrook, NY).

 

Thanks again Rick! You're my hero! I didn't pull that part up and look underneath. I only changed the 6 rubber gaskets that I saw. lol. If I have to pull this thing back apart to fix it I'll make sure to change those gaskets while it's apart.

While I have you, is it very common to push one of those upper plenum gaskets down in the hole or partly down in the hole when replacing the intake manifold? My car runs like it's got a huge vacuum leak and I was thinking maybe when I replaced the intake I accidently pushed a gasket down? I guess I could spray a little carb cleaner in that area while the engine runs and see if the RPM's change, eh?

I'm still trying to get time to take the car to have the codes checked..............

 

One of the Tech's here at the Chrysler Dodge Jeep Ram dealership where I work used his Snap-On scan tool to pull up the codes. There were a couple pages worth. I caused a lot of them when I was unplugging and re-plugging the coil packs while the car was running to see if the new coil packs were bad. I also didn't have the air filter cover replaced when I first started the car so there was a map senser disconnected code too.

We desided to clear all the codes and start over because there were just too many. After clearing the codes I started the car. The engine light is off but it still says Restricted Performance on the dash. The Tech wants me to drive it home and back tomorrow to see if any codes come back.

I'll post again tomorrow after we see what codes we have. Thanks!

 

OK. I drove the car home and after getting here I hooked the scanner up and got the following codes.

P0305 - Cylinder 5 misfire
P0355 - Ignition coil pri/sec circuit malfunction
P1313 - MFG control ignition system or misfire
P1000 - MFG covered fuel air metering

Can someone tell me which cylinders are which? (1-6)
Can someone explain what these codes mean? ( P0305 is kinda obvious)
Is this the cylinder in the very back on the passenger side that you can't reach?

Thanks for the continued support guys.

 

Go over your coil/plug work.

 

If I may.... bfsgross makes a good point. I struggled with a similar issue with my e class. I would suggest you wiggle each wire connector (checking for a shorted connection) to the coils and check the pins in each coil connector. You may be surprised what you find. I had multiple misfires. Turns out I had one crushed pin connector that was throwing the whole ignition timing out of whack.

 

The snapon is reporting some completely wrong meanings and also failing to give you proper detail. Look the codes up in the codes PDF from the FAQs (or JTIS).

 

Anybody care to share which cylinder is number 5? I'm more used to working on Chevy or old Mopar engines.

Never mind. I found it. https://www.jaguarforums.com/forum/a..._numbering-pdf

Thanks.

 

MY 2003 and up:

 

I just wanted to let everyone know the end of the story that was following my troubles with my S-Type. The misfiring codes I was having along with the "Restricted Performance" message on the dash while the car was running horribly are now gone. I'm glad to say that after changing the plugs, coil packs, intake gaskets and IMT o-rings that the continued misfire and rough running engine was not due to my poor workmanship.

One of the brand new coil paacks I bought was DEFECTIVE!!! Arrrrrrrrrrggggggg!!!! Of course it was the one all the way in the back under the intake manifold where I couldn't reach it so the entire front end of the car had to come completely apart again.

I bought the first 6 coil packs from www.rockauto.com. I bought the most expensive of the 4 choices they offered. It was $38.00. One of them was defective. I bought one locally at Advance Auto Parts for $54.00 to replace it and now my Jaguar purrs like a kitten.

Thanks for all the help diagnosing the issue, especially to Rick (Joyce's Jag). The pics really helped me. I'm just glad the problem wasn't my fault! lol. Now to see if Rock Auto will take a return on the defective coil pack...............