ORIGINAL: Mallonpaulj

Good stuff from all.

I have the fuel pressure gauge installed at the schrader valve fitting near the alternator. Its a steady 30 psi till I rev the engine. It will spike to about 40-45 then while the rev's are still up, it drops back to the normal thirty. Acts like an accelerator pump, only increasing while the throttle is being depressed, then back to normal range. Drop the revs, stays at 30 psi.

I think the cats are new along with the entire exhaust within the last 20K mile. I have put about 10K on it in two years. The flowmasters look like new as do the cats. I will check them by disconnecting the exhaust from the cats and mufflers and see if the miss improves.

On the type of miss, it does not feel like the engine just shuts off (like turning off the spark); it seems to erratically stumble. If I hold it at ~ 4k you can feel some and as you go 200-300 rpm more, it gets dramtically worse. The car will not pull past 4300 (at least I won't keep pushing it when the miss starts). In first, it sometimes will get near 5k before its starts and when its cold outside, it seems to be better. That is what I found to be strange. One cold day (I normally leave it in the garage all winter), it seemed to be able to pull 5k consistently. Felt like the miss had just moved 'up' a 1000 rpm.

I am putting in a 155 lph pump in a couple weeks. Hoping that its just not able to keep up though with 19lb injectors, that should not be an issue. I have NO idea what the inside of the tank is like (rust?) or the condition of the pickup filter. Could be full of birds and bugs for all I know.