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96XJ performance mods advice??

If you put a straight edge through the center of the cam & crank sprockets, it should also go through both dots like in the pic below. If not, you'll need to realign them.

Timing_Gear.JPG
 
Got everything allign, used the degree wheel and a piston stop method and it worked out fine. The harmonic bal. must have split, it was almost 1/2 in off from the TDC mark.
The only concern I have now is that from idle to 2000 rpms is sluggish or it bogs. As itsoon as give it gas it nose dives or hesitates then it takes off. Feels like a lean condition. Maybe the big valve head, cam, 63mm tb and CAI have something to do with it?
 
Dont know about degrees, I used the wheel to measure TDC with the piston stop. Exact middle between the two stops. I wich I had taken some pics. I have read all over different forums and I guess the 96 to 98 xjs can be a pain set the timing just right. Im sure my timing is still little off, but that can make big difference specially with a new Cam.
It idles fine but it just has that instant hesitation as soon as I hit the throtle, specially if I punch it, just flattens out like it wants to cut off, i have to ease on the gas so it wont do that. From idle to about 2500 is flat. I have called Clifford Performance and they keep advising me that is a timing issue. Can the big valve head or the 63mm TB have anything to do with this issue?? or any of the sensors, which I replaced? They are all new other than the MAP sensor....
 
Dyno, I did just that as you can see in my third pic...This timing issue is trying my patience. But I will figure it out, no hurries here..

I appreciate all the input from everyone
 
RudiXJ said:
Dont know about degrees, I used the wheel to measure TDC with the piston stop.
Click to expand...
Ok, but what the numbers you pulled off the degree wheel for the cam? Exactly what did you do with teh degree wheel?
Im sure my timing is still little off, but that can make big difference specially with a new Cam.
Click to expand...
being a little off on cam timing won't cause your issues.
Can the big valve head or the 63mm TB have anything to do with this issue?? or any of the sensors, which I replaced? They are all new other than the MAP sensor....
Click to expand...
The big valve head and TB shouldn't give you this problem.
 
I got a wheel that's about the same size as the harmonic balancer 7.5 in. a then I marked the TDC on wheel my original TDC Mark was. Next I installed the piston stop on #1, to make spinning easier I removed the rest of the spark plugs. Turned the crank clockwise until it stopped, marked it the wheel then counter clockwise until it stopped. Marked that on the wheel. Then measured the distance between the two marks. It was about 14 degrees (before TDC) from my original TDC position... But I still think I'm off a tooth or two.
 
I have no check eng. light and my scanner doesnt detect any codes. Can any of the sensors that can cause this issue be malfunctioning??
 
I checked my fuel pressure and it was fine, 49 psi at idle, but the fuel pressure doesn't bleed down, stays after ignition off. The pressure stays at 47 psi (5mins). Is that a issue?
I also ck the timing again, repositioned the dizzy. She starts right up and idles fine but still, the instant I hit the throttle she bogs down. The rpms go down a couple hundred. then revs up strong. Dr. Dyno has a good write up on Indexing the dizzy, that I followed. He mentions that the ears come off for a aftermarket cam. Others mention it on other sites. BUT there is no write up that I cant find...Well, I grind the ears of the dizzy, paint marked everything before removal, tried to advance and retard the timing, but it did not do anything for my problem.

No codes, replaced all my sensors but the MAP.
No vacuum leaks
No leaks at all

Can the PCM or MAP be defective without throwing a code???

Can a clogged Cat cause this issue??? still has original. Tomorrow she is going to the shop to have a new front pipe and a new Cat (Thunderbolt) replaced.
 
RudiXJ said:
I checked my fuel pressure and it was fine, 49 psi at idle, but the fuel pressure doesn't bleed down, stays after ignition off. The pressure stays at 47 psi (5mins). Is that a issue?
I also ck the timing again, repositioned the dizzy. She starts right up and idles fine but still, the instant I hit the throttle she bogs down. The rpms go down a couple hundred. then revs up strong. Dr. Dyno has a good write up on Indexing the dizzy, that I followed. He mentions that the ears come off for a aftermarket cam. Others mention it on other sites. BUT there is no write up that I cant find...Well, I grind the ears of the dizzy, paint marked everything before removal, tried to advance and retard the timing, but it did not do anything for my problem.

No codes, replaced all my sensors but the MAP.
No vacuum leaks
No leaks at all

Can the PCM or MAP be defective without throwing a code???

Can a clogged Cat cause this issue??? still has original. Tomorrow she is going to the shop to have a new front pipe and a new Cat (Thunderbolt) replaced.
Click to expand...

The fuel system staying pressurized after you turn the engine off is normal. If it didn't keep pressure, then you'd have a leaky check valve. You can look for a used OEM map sensor on ebay. They get them from the junk yards, clean them, and test them to make sure that they are selling a perfectly operating sensor. Much cheaper than even getting a new ching-chang map sensor and they are oem mopar. I'm running a junkyard oem TPS and a map sensor. Truck runs perfectly!
 
if you have a multimeter you can test the MAP sensor. The TPS is best tested with an analog voltage meter.

Also, make sure your MAP sensor is actually hooked up. If you have the one on the throttle body make sure that the little 90* elbow is still connected.
 
I wasn't able to engage that guy for a TB (unanswered emails). Search on ebay, that's where I got mine with no issue. I can look up the vendor name if you want.
 
Got the 63mm TB from eBay seller (xtreme-fi). I wonder if thats where issues are coming from. I inspected the TB and found a tiny hole inside the bore lower half, under the butterfly. Can that cause any issues???. The hole is about 1/16th in.. I was going to notify the seller but something came up and I totally forgot about the hole. Installed the TB 3 weeks later. :mad:
 
Have you let it run long enough for the computer to learn and compensate for all the changes. If you have a Scan tool that reads live data you can watch the fuel trim and timing. Most these scanners have a noticeable delay from when the engine responds to when the scanner displays.
 
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