Fuel pressure

[92sseislug]

Does anyone here know what the fuel pressure should be on a 92 ssei when checked from fuel rail? I think that it may be more of the culprit in why my car runs like it does. Half throttle it runs fine, more than half and it sputters and falls on its face. I checked pressure at rail and get 35 at idle and 45 with vacuum line pulled from regulator. No smell of gas.

I took the advise and just put the original 92 parts back on for the time being.

[mhfromphila]

If you haven't changed your fuel filter, I would change that first and see how the car runs.

[92sseislug]

fuel filter was replaced right before winter. car acts as follows, light acceleration does fine, medium accel starts to shudder, hard accel and it shudders, bucks, backfires, and stalls.
i have no ses light or codes when it does this. I have three icm's, 9 coils, two fuel pumps that all have been swapped around. first two icm's gave me code 43 electronic spark control circuit, both pumps have same pressure readings. If I disconnect MAF its bucks and backfires more, no change if I disconnect BCS. I have gone through all vacuum lines and checked them. I have cleaned the grounds under the icm. I have no idea why it would run like this and set no codes or illuminate the ses. plugs(ac delco) and wires are about as old at the fuel filter.

[00Beast]

Get the fuel pressure with the engine off, key on, engine running at idle, revving the engine slightly, and then watch it after you shut it down, see how long it takes for the pressure to bleed down. Then post your findings here. Someone should be able to give you a good answer.

[J Wikoff]

Do you have the 92 fuel pressure regulator installed?

Mine had a similar problem, and it got worse the warmer the car was. The harder I pressed the gas, the worse it ran. I replaced the regulator, and it got better, but didn't go away. I replaced the pump and all is well.

35 psi at idle is low. 45 with the vacuum line pulled is a bit low.

[92sseislug]

Had tester hooked up while driving and it would jump to 55 psi. I have let it sit hooked up for an hour watching it but it went up and not down in pressure by like 4 psi. Yeah its the 92 regulator, believe its 3.0 bar. I have the 2.7 and 3.5 layin on my bench.

Last night i did most of the swapping/cleaning and got the car to want to spin tires while shifting gears with the MAF unplugged with no hesitation or anything at WOT. Then shortly after getting back home(5 min maybe), got asked to take brother in law to get more beer and it went right back to the way it was. Car was at operating temp all night.

[92sseislug]

So I did some other testing of my own. While in park reving engine it would act up, put my finger in to block BCA arm from moving down and rev up again this time no hesitation nothing. What would cause it only to hesitate only under boost? I didn't rev for too long just long enough for it to increase in rpm.

[J Wikoff]

If it seems to run ok with the MAF unplugged, imagine how much better it can be if the MAF is hooked up. I'm not sure what's going on, but my offer still stands.