1998 Chevy 350 Problem Starting (Oil Pressure Switch?)

I am having problems starting. It will crank for several tries before it starts. Each time it seems to take longer. When I restart it after running, it fires right up. I replaced the fuel pump about a year ago.
When I turn the key, the fuel pump powers up normally. I checked the fuel pressure and it is normal. I just replaced the fuel filter, no help. I tuned it up a year ago also and just checked the plugs, all fine. I replaced the distributor cap and coil but not the coil module. The wires were replaced also. I am thinking it is clogged fuel injectors or maybe the oil pressure switch. The oil pressure is reading normal while running. It runs without missing. It accelerates normally but when I floor it, it bogs badly. I am going to replace the oil pressure switch but I cannot locate it. Any help would be appreciated.
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It is not the oil pressure switch.
Have you ever replaced the ignition module in the distributor?

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I am not positive but I don't think my year has a replaceable module in the distributor. It does have a ignition coil module that connects directly to the coil. I have not replaced it but I have replaced the coil.
News Skimmer wrote:

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I'd get a pressure gage on the rail, if vortech, you need 65 psi for starting.

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snipped-for-privacy@yahoo.com wrote:

I'm having the same problem in my 1997 K1500 Z71 right now. I've just replaced the intake manifold gaskets & found out that after removing the distributor (which had its' clamp not so tight) the only way to get timing back in order is to hook up to a scan tool to have cam retard set to 0 degrees. The module in the distributor itself is no longer a pickup coil, it's a cam position sensor. It has to be synced to the crankshaft sensor to properly control ignition advance. I'm having this done tomorrow. Hopefully I'll get back to virtually instant starts again.
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Did you have the same issues before it finally wouldn't start? This seemed to happen over a month's time. I wanted to try everything else before I tore off the upper and lower intakes. Also that is the only way to get to the fuel injectors for those year 350's (no fuel rail). I thought the injectors were the problem.
syoung wrote:

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Yes, my starting issues have been coming on for several months. It hasn't got to the point of no starting - just very long cranking. I was thinking I had a weak regulator & intermittent fuel pressure drops. You don't have to take off the lower intake to get at the injectors or the regulator. With 132,000 mi. I thought it was time for gaskets anyways so I replaced them & the regulator. Then I realized the cam position issue. On the first start after the work last Monday it started great. Been getting worse again since then. I'll see what happens today after the shop does the sync job.
tonyb3147 wrote:

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Thanks for the help. I am curious to see how it runs after the sync job. Mine has 135,000 and it sounds like a typical GM problem.
syoung wrote:

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Well my truck wasn't far out of sync. Only -4 degrees off. Crap - I wanted to see more than that. It does run better though - I didn't have the stumble during acceleration that I had while driving to the shop. Starting has improved but I thought it would be even better. Possibly time will help to relearn some settings. Took 10 minutes at a local shop & I was only charged $25.00. Cheap & now I know it's set right.
tonyb3147 wrote:

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I pulled off my upper intake manifold and holy crap, there was so much gunk laying on top of the lower intake and puddles of gas. The injectors are really funky too. I plan on replacing the regulator while I have it off. I am in the middle of pulling off the lower intake and of course there is one problem bolt underneath the AC compressor bracket. Let me know if you pulled off the power steering pulley to get that bracket off. Did you say you replaced any of your injectors? Thanks.
syoung wrote:

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I didn't replace any of my injectors - just cleaned everything off down there. Messing around with that AC bracket looked like too much work to me. I used a hole saw & removed some of the casting directly over that one bolt. Problem solved forever. That bracket should have been cast that way to begin with in my view. I don't feel I've weakened it to any appreciable degree.
tonyb3147 wrote:

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Well I believe I found my problem. I have a code scanner/simulated dyno software for my Windows based laptop. I get nice live data graphs of major sensors. I felt that my throttle position sensor might be questionable so I've been monitoring it for several days. No luck - graph never gave me any glitches, spikes, etc. Voltage check through sensor was good too. Damn. So what, a new one only cost $28.00 so I bought one. Took off old unit to find that it had about .100" end play! Hmmm. Put on new unit - acceleration & quick starts came back after a day of driving back & forth to work. Yahoo!
syoung wrote:

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syoung....what hardware and software system are you using?

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I bought this - http://www.auterraweb.com/dynoscankitwindows.html - for $199.00.
News Skimmer wrote:

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I am having it put on a scan tool today at the shop to have them sync the cam position sensor. It seems to run pretty good right now after I have rebuilt the heads and replaced all of the fuel injectors and regulator. I did think about replacing the throttle sensor but never got around to it. But for $28, you might have a good point.
syoung wrote:

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