94 deville ,the valves are pinging, and after its been driven its very hard to start.Like the batt. is weak, its a new batt.can the timing be advanced?or does a mech. need to do this type of thing.

are you running premium fuel in it ?

if so id would check the EGR valve operation before checking the timing....

hard to start ? the engine turns over right ? just wont "catch" ?

Big Bear-

as far as the hard start on hot engine, it could be a weak starter. I had this happen on my 1991 Deville (may it R.I.P.), it would sould like the battery was getting really weak and turn slooooooow when I'd try to restart it after the engine was at normal operating temp. A few times I was almost afraid I'd get stranded, but she always came through. I ended up replacing the starter and never had that problem again.

Of course, you should check out your battery and alternator to make sure they are suspect, but since you said this is happening on a hot start, I would potentially suspect a starter going bad.

Kevin

'94 was a 4.9 and it does not have a knock sensor so it will not tolerate low octane fuel like a Northstar will as Stoneage suggested. Follow his advice if you are using premium.

A leaky FPR will cause hard hot starts. FPR is located on the fuel rail and has a vacuum hose off the top of it. With the engine running pull the vacuum hose and look for fuel leaking out of the nipple. There should be none. If there is, depressurize the fuel system and replace the FPR.

A leaky FPR will cause hard hot starts. FPR is located on the fuel rail and has a vacuum hose off the top of it. With the engine running pull the vacuum hose and look for fuel leaking out of the nipple. There should be none. If there is, depressurize the fuel system and replace the FPR.
i was wondering if an fpr would do that ....ive never gotten to troubleshoot a leaky one yet so i had no idea what they would do ....

you know that holds water tho ...cuz if you dont get enough fuel the cylander temps would come up causeing a ping too ....hmm , good call on that dude ..

94 deville ,the valves are pinging, and after its been driven its very hard to start.Like the batt. is weak, its a new batt.can the timing be advanced?or does a mech. need to do this type of thing.

for starting problems (more prononced after long drives) read this:
http://www.cadillacforums.com/forums/showthread.php?t=42099

Concerning pinging... if you get it undr slight acceleration (gas pedal barely pressed) when engine is 180 and up, it's most likely lack of EGR flow. The ECM advances ignition assuming where is exhaust gas flow to cool the cylinder down but you do not have that flow and as a result get spark knock.