cold starting problems

[newpiper]

new to the forum. need help. 93 s-10 blazer 4.3L CPI with 267,000 miles. about a month ago the truck became hard to cold start and was running rough after warmup. it would never start on the first turn, start sometimes on the second turn but run very rough for 15 seconds or just die, and would almost always start on the third turn but run very rough for 15 seconds. i replaced cap, rotor, plugs, wires and that fixed the rough running problem after warmup but the hard cold start problem remained. (it runs fine after a short warmup and gets 19+ mpg.) truck has a LinderTech CPI/regulator/spider and new fuel nuts (lines) at about 180,000 miles and new fuel pumps at about 180,000 and 250,000 miles. i checked the fuel pressure and it holds about 50 psi at key-to-run and holds the pressure for more than 2 minutes (at which point i terminated the test.) this has been going on for 3 regmogas fill ups at the same station and now a 4th with premium. no SES either. any ideas? midwest winter is coming and this will definately cost me a starter. thanks.

[MT-2500]

Originally Posted by newpiper

new to the forum. need help. 93 s-10 blazer 4.3L CPI with 267,000 miles. about a month ago the truck became hard to cold start and was running rough after warmup. it would never start on the first turn, start sometimes on the second turn but run very rough for 15 seconds or just die, and would almost always start on the third turn but run very rough for 15 seconds. i replaced cap, rotor, plugs, wires and that fixed the rough running problem after warmup but the hard cold start problem remained. (it runs fine after a short warmup and gets 19+ mpg.) truck has a LinderTech CPI/regulator/spider and new fuel nuts (lines) at about 180,000 miles and new fuel pumps at about 180,000 and 250,000 miles. i checked the fuel pressure and it holds about 50 psi at key-to-run and holds the pressure for more than 2 minutes (at which point i terminated the test.) this has been going on for 3 regmogas fill ups at the same station and now a 4th with premium. no SES either. any ideas? midwest winter is coming and this will definately cost me a starter. thanks.

Welcome to AF on your first post.
Is it a W engine code?
If so you need to work on that fuel pressure.
Specs on the W engine is 55/61 lbs of fuel pressure.

Guide line for checking fuel pressure.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Yours is 55/61 specs
Cold start should be 55/61 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 55/61 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.

MT

[newpiper]

MT, thanks for the welcome and the advice. It's a W motor. I'll post fuel pressure from the diagnostic regimen you provided, but not today. The alternator just gave up so I'll be spending my time on that for the moment. However, I'm noticing now that the fuel pump at key-to-on (half tank of gas) is sounding a little grindy as opposed to the smooth purr I think it should have. If it turns out to be the fuel pump that will be the fourth since I bought the truck used at 30,000 miles. Original was GM, but all the rest have been Carter and a new fuel filter each time. Any pump better than any other?

[newpiper]

MT2500, thanks for the help, but no point posting diagnostic pressures. truck died on the way to work friday and no pump noise at KO. got it towed, replaced the pump saturday. backfilled the pump from the pressure line before i connected everything up. ran it to test for leaks and all is OK. now an odd situation. at KO the pump shows 60 psi but when the relay shuts off the pressure goes...immediately...to 52. idle pressure is 52 and road pressure (40 mph) is 53-ish. is this right? brand new carter pump does not meet the pressure spec?

[MT-2500]

Originally Posted by newpiper

MT2500, thanks for the help, but no point posting diagnostic pressures. truck died on the way to work friday and no pump noise at KO. got it towed, replaced the pump saturday. backfilled the pump from the pressure line before i connected everything up. ran it to test for leaks and all is OK. now an odd situation. at KO the pump shows 60 psi but when the relay shuts off the pressure goes...immediately...to 52. idle pressure is 52 and road pressure (40 mph) is 53-ish. is this right? brand new carter pump does not meet the pressure spec?

Is it running good and starting good now?
The pressure is just a little low.
But the main thing is to watch for a fast leak down.
Remember the fuel pressure regulator controls fuel pressure.
Pinch off return line or check fuel pressure direct at fuel filter to check for full fuel pump pressure.
The fuel pump check valve can give a pressure leak down to.
And make sure your fuel pressure gauge is up to par to.
MT