Whenever the outside temperate gets below ~60 degrees or less, the next morning when I try to start for the first time, its starts but then immediately dies after a few seconds.
Most of the time, if I give it about 1 minute between cranking attempts, it eventually stays running, but can take about 20-30 attempts (pause 1-min, turn-key, repeat). So very annoying (recently replaced starter) and I live in Minnesota so and have been parking over the winter each year. If I DO NOT add a 1 minute pause (or more), the engine does not want to start at all.
Once it stays running, it runs normally and can stop and restart anytime and multiple times. In the summer-time, if I leave it parked unused for say a week or more, and first time starting, it sometimes will do the same but usually only once (start, runs a few seconds immediately die, pause 1 minute, start).
1997 GMC Sierra K1500, 190K miles, 4WD, automatic, Vortec V8, 5.0L
Fault Codes: P1351-18 (IC output high/pulse detected when gnd_cyl. 1) and sometimes P0172-18 (Fuel trim system rich bank 1/2)
At first I thought it was the fuel pump so took the truck to my trusted mechanic a few years back but he does not seem to be able to nail down the issue and he said the fuel pump pressure was good. Things he tried: replaced ground wiring strap to block, Engine Coolant temperate sensor. I think it just finally starts/stays-running for the mechanic and makes him "think" he found root cause and he claims he fixed it. Sometimes I take it back to him in summer and never shows the symptoms.
I tried the parts cannon also with: Replaced throttle position sensor a few years ago and last summer I replaced the MAF and no cold start issues until fall temperature reached below ~60 degrees (good grief).
The following is a audio recording of the multiple cold start attempts. If you listen closely towards the last few attempts, the engine is dying but then almost recovers. Eventually it runs and stays running after I stopped this recording.
https://youtube.com/shorts/4OBxLldaVwk
I was leaning to an electrical issue since the truck runs fine after and stays running the rest of the day, and starts anytime afterwards while the engine is still warm. Is there any diagnostic procedure on any other sensor that may be causing the cold start issue?
However, wondering if it could be the fuel pressure regulator problem which is a real pain to replace with these Vortec fuel injector as you can see in the following video:
https://www.youtube.com/watch?v=_6Iipjvif0Y&list=LL&index=19&t=1101s
Is there a diagnosis procedure I can use to confirm if the fuel pressure regulator is the problem? Could colder temperatures cause a faulty fuel pressure regulator to operate poorly... perhaps this is why the 1-minute pause between cranking attempts it needed...
Thanks in advance for your time.
Is there a diagnosis procedure I can use to confirm if the fuel pressure regulator is the problem?
Hook up a fuel pressure gauge. Note that there should be residual pressure held in the fuel rail when the engine is off for faster starts.
You might also perform a diagnostic scan for codes and live data. Fuel mixture problems should show up in the fuel trims.
@chucktobias Did you get a chance to listen to the audio recording (please listen to the whole recording where it gets more interesting at the end)? As I mentioned my mechanic tested the fuel pump but maybe its not acting up when he was testing it so I will need to purchase one. What should the pressure be with a) key on but not trying to crank, b) cranking and c) running? Would it be possible for Scotty to listen to the audio recording also?
See the diagnostic scan codes I reported (what the anyscan A30M V2 tool reported). The problem with using/getting live data is the nature of the problem is before it stays running... so live data would not likely be able to show what the real issue was before when it kept dying when starting cold.
Is there anyway to attach a scope (which I have) or some type of test equipment that would tell me if its a problem on electrical side that would show if spark plugs are getting energized properly and not getting cut off.
Did you get a chance to listen to the audio recording (please listen to the whole recording where it gets more interesting at the end)?
I can't really tell anything from those sounds.
Would it be possible for Scotty to listen to the audio recording also?
Scotty picks a few questions to answer here each day. He can't answer them all, the rest are answered by the community. You could try contacting Scotty directly (see the FAQ.) Be aware though that he gets tons of email.
What should the pressure be
That information should be in the shop manual. You can find a free one online at the link below:
The problem with using/getting live data is the nature of the problem is before it stays running... so live data would not likely be able to show what the real issue was before when it kept dying when starting cold.
Fuel trims would show you if you're running too rich or too lean.
Is there anyway to attach a scope (which I have) or some type of test equipment that would tell me if its a problem on electrical side that would show if spark plugs are getting energized properly and not getting cut off.
Physical examination of the spark plugs should reveal abnormal combustion conditions. Since that vehicle's ignition uses a distributor the condition of cap, rotor, and ignition wires should be checked. Noid lights can tell you if the injectors are being pulsed.
For deep electronic diagnosis you would probably need a Tech2 (GM dealer scan tool when that truck was made), or the equivalent in a modern scan tool.