Actually many things can be off for this behavior where there will be no codes (maf, fuel delivery, coil as mentioned)

No easy answer am afraid, check everything methodologically is the only way forward.

And don't push it until you resolved the issues is the best advice I can give!

 

That is true but a coil pack will give you a code but a spark plug wouldn't....... I done some work on an XKR with a killer chiller and that had 3 melted plugs, ran like a bag of crap.......!

 

Coil packs can also underperform, ie not capable of delivering anymore to what it should, then there is no code, and issues when it has to deliver. Had it more then once actually, therefore I have this:
https://www.jaguarforums.com/forum/j...tester-143357/

 

vg99999....

I'm going to mention something, as I understand it, you are having problems getting the Engine to rive-up....In other words, it's bogging-down.....after about 2500 RPMs....You hit it to go and it starts to an Boggs down, every so often I have that problem and have to replace the Rubber gaskets around the S/C "Hat"! The "Hat" also has 6 screws that hold it down...Under the "Hat" there is a Rubber Gasket that sometimes starts leaking and has to be replaced.....Each screw that holds it down, also has a rubber gasket that starts leaking and then you have the 2 Rubber Gaskets on the runner where the "Hat" hooks -up with the intercoolers......You can get new better than stock Rubber gaskets for the Seal Plates from Eurotoys in Chicago. The other Gaskets may be a Jaguar item. Also, look at the By-pass Valve and the actuator...If the By-Pass Valve is open (could be dirty), it will not let the Blower push any air into the Engine, it blows it back toward the Throttle Body.....In other words, it sounds to me like you are losing Air and not getting it into the Engine. Eurotoys has made a Gasket Kit to solve the connection problem....They have put groves on the Rubber gaskets and the Seal Plates....With all the pressure from the double Pulley set-up, I have noticed on my Snow Performance pressure gauge as much as 25 Lbs. I have made this statement before and several of the Guys have jumped me about it.....But that is what it says! Now that's enough pressure to blow-out some of these Rubber Gaskets....As a matter of fact....I'm going in Tomorrow for some new gaskets myself.....

You should look into this as I think it's your problem!

Billy Clyde in Houston

 

Thank you. Sorry for pause, last week abroad, coming home in few days and will check all those things asap.

And regarding fuel pressure, maybe this manual regulator that we have installed is useless, and is the reason? What if I will set stock fuel pressure (with both pulleys upgrade, I never tried it), will it not damage the engine on high rpms?

 

Thank you Avos! Sorry for pause, last week been abroad, will come home in few days and check all those things asap.

And regarding fuel pressure, maybe this manual regulator that we have installed is useless? If I go back to stock pressure with both pulleys etc (I never tried it after upgrade), will it not damage the engine on higher rpms?

 

Thank you! Yes, will read the codes in a few days when return home. And as I wrote above to members, is it safe for the engine with all those upgrades to run on stock fuel pressure? Maybe this raised fuel pressure is the reason?

 

Thank you Billy, will check that too! Very interesting.

 

vg99999,

Friday, after running about a week with the Jag bogging down every time I pushed it a little, I popped the "Top" or "Hat" or whatever you call the aluminum thing with the "V8" on it,, I had bought some Rubber Washers for the Hold-down Bolts. When I started pulling them out, I found that all of them had broken down, allowing the Blower's pressure to leak by......I replaced them and off I went....No more Bogging down! a completely different car.....Pressure Gauge is back to reading between 22 to 24 lbs.
All is well again.....!
I have found that most of the time, it's these Gaskets that "Blow"! I haven't had a problem with the Seal Plate Gaskets, since I bought the Kit from Eurotoys. So, I think that solved that problem.....That's been a couple years now....I was also having problems with the Engine in general a year or so ago...but found that after I replaced the ECU everything seemed to smooth out! So, today it's running super but I need to send my old ECU back to Eurotek and have it repaired and set-up for the "Big Pulley/Little Pulley" set-up...They won't tell me what they do but I does make it run a bit quicker.... I don't see that helping the "Blown Gaskets" problem though. In other words, I'm going to have to find something better than the current Rubber Washer set-up to stop Blowing them out...

If you or anyone on the Forum that reads this knows of a better Rubber Washer or maybe a Plastic Washer that will fit or if you have found a better way.....Please let me know!

Avos is right about the MAF Sensor and Intake Tube....Go back to the original tube set-up and use the regular MAF Sensor. Those Mina Tubes don't help as the ECU does read the MAF Sensor correctly....You can work with the Tube and take some of the kinks out of it and seal them up, so it will breath a little more. That's the way to go with the intake. After all, you are pulling a lot more Air down that Tube.....Your double pulley set-up has to get Air somewhere....Remember?

Our S/C is good with the "Big/Little" Pulley set-up to a point but it reaches a point of Air/Volume and RPM's and at that point, it is through.....Time to shift up to another Gear....It does all I want it to do and that's to worry a Corvette or a Porsche every now and then!

Hope you find your problem soon! Look into these ideas that I have found, as I think they are your problems as they were mine....Oh! The Snow Water/Methanol injector really works well on my system. It does everything it's suppose t do and anytime you want to go Porsche hunting....You can pour a little bottle of Nitro in the Water Tank and really have a Ball. Probably good for around 50 to 75 HP......I buy it by the Six-Pack!

Have a good day!

Billy Clyde

 

Deeply appreciated all your replies! Now taking XKR back to the workshop in a few days, the only one question remains for now - from anyone's experience - is it safe to run engine with stock ECU and stock fuel pressure with both pulleys upgrade? Especially on highest rpms? Or it's necessary to increase the fuel pressure to compensate higher boost?

 

vg99999,

I'm currently doing that! As I said, my ECU, the one that was 'Tuned' by Eurotek, went haywire on me and I put a Stock One back in....Still think about sending the "Tuned" one back for repair as I'm sure it will help! Unfortunately, the 4 Liter ECU can't be Tuned....As I told you earlier...It has probably picked-up at least 40HP....Once again, try the Snow Water/Methanol injector that's the next step before you change-out the Intercooler Radiator up-front..

Billy Clyde