Please Help with starting issues.

Okay. Here goes nothing.
I drive to work at 5 in the afternoon and work 12 hours. Get in my truck at 6:30 and it will not start.
Acts as if it is getting no fuel or ignition. It will turn over and over but not start. I can turn the key on try to start then turn the key off again and after about 2-5 minutes of cranking it, It starts. Once it starts it runs great.
When I get home 20 iles later it starts as if nothing ever happened.
It does this every morning.

Can the MAF Sensor cause this?

I have no CHECK or SERVICE engine soon lights coming on.............

Thanks in Advance

[old_master]

What year, make, model, engine?
Have you checked fuel pressure and leakdown?
Have you checked for spark?

98 S-10
4.3 v-6

Have no way to know for sure about fuel. Shops prices are too high. IS there a cheap way to check for fuel or spark while doing this alone?

As for leakdown? If I wait 12-13 hours and can start it during the daytime hours without incident but it has a hard time starting early in the mornings after I get off work, would that give a clue to anything?

I'm no mechanic. A friend suggested the MAF sensor due to him having a similar issue.

[old_master]

Extremely doubtful on the MAF sensor, save your money. A quick easy way to check for loss of spark is pull the coil wire off of the distributor and rest it, (don't hold it) about one half inch away from the engine, (ground). Have someone try to start it and watch for spark at the wire jumping to ground.

Checking fuel pressure and leakdown requires a fuel pressure tester. This is a more likely cause than loss of spark, so it might be worthwhile to invest in a tester. Harbor Freight has one for under $20. It's not professional by any means, but it'll do the job. Key on, engine off and cold, fuel pump running, pressure must be 60psi to 66psi and must remain above 55psi for 3 to 5 minutes after the pump shuts off.

I am a little confused at how it only does it in the morning but starts right up in the afternoons. 12 hours between starts and it only happens in the mornings.

[MT-2500]

Cold start you need full fuel pressure to squirt injectors.
That is why you were told to run as fuel pressure test.
There is no easy button.
We can not help if you do not follow instructions and run proper testing.
Some parts places like AZ also loan rent or sell fuel pressure tester.

Post back fuel pressure for help.

MT-2500
Sorry, old_master sent me a link on how to do the test. It was not posted here. He sent it to me privately.
The test was normal and that is why I asked why it only did it in the mornings.
I let it set for 24 hours and cranked it at 4 P.M. yesterday afternoon and it started right up. I went out at 6 A.M. this morning and I had to crank it awhile before it would start.

THAT SAID.

I was looking at my vacuum lines for my a/c and when I replaced the lines there were 3. 1 was 5/32 and went into the fender well where the vacuum /box/ball whatever is located and one runs under some wires. The 7/32 hose runs from the connector you see to what I assume is the top of the FUEL PRESSURE REGULATOR.

I will try to see if the vacuum lines help the issue.

It fixed my vents that use to only blow out the front and not the defrost and floor.... woohoo
See photo:

[old_master]

The larger line on the black side of the check valve goes to manifold vacuum. It is the vacuum supply for the HVAC system and the 4WD. The fuel pressure regulator in inside the plenum and does not have a vacuum line connected to it.

Connect your fuel pressure tester, then restart to pressurize the system. Then shut the engine off for the day.... When you try to start it the next time, notice what the fuel pressure is before you turn the ignition on and while cranking.

Guess I was about to buy the wrong fuel pressure regulator. Dude at the dealership showed me one where the fuel return line and vacuum line plugged in?

Also, I removed the air plenum from the top of the motor to access the vacuum line and forgot to reattach the big tube that plugs into the back of it. My SES light came on and I scanned it. Codes P0171-P0172 came up. That covers about 5 things to check. Including fuel injectors.

OH, Do you happen to know how to get to that canister in the fender well? My hands way to big.
Thanks

Guess I am really lucky to have you guys around.
Thanks again.

[old_master]

The fuel pressure regulator attaches to the fuel injector housing. It has a nipple on the back end of it that a hose could fit onto.

It doesn't need one because the entire inside of the plenum is exposed to manifold absolute pressure, which is what operates the diaphram inside the regulator. This holds true on both the CSFI and the CMFI engines.

Okay, I see how that fits now. He did not know exactly what he was looking at apparently. He told me the vacuum line went to the fuel return nipple. I asked a mechanic and he explained it to me.

Now, any photos of how to remove and install it?

I will try to start it again in the morning. I will be working tonight.

I think that if the fuel system is the problem then I should start cheap.

However, I did install a new fuel filter about a month ago and I had problems getting it to snap in on one side. I had to wiggle it around until the one tab snapped in place.
I'm guessing that would not be an issue.

[old_master]

Pressurized fuel comes from the pump, through the filter, past the service port and directly to the injectors. The green arrow going into the regulator is downstream, (after) from the injectors. Spring pressure on the diaphram is what allows the pump to build pressure. The arrow going out of the regulator is the fuel return line back to the fuel tank. The regulator is pretty simple and rarely fails, don't start throwing parts at it before diagnosing the problem.

What steps should I take if all the fuel pressures come back normal?
So far the pressure have been around 62-64 give or take. The onlt thing I'm not comfortable doing is using the shut off valve.

Cannot see any visual fuel leaks or signs of leaked fuel like some say they are able to notice.

It has spark at start up and it does not hesitate, backfire, or miss.

[old_master]

If pressure and leakdown check out when it's acting up, the next step is to see if ignition is being lost.

No external leaks is a good thing! The problem could be an internal fuel leak in the plenum or in the tank, and that will show up as excessive leakdown. If that's the case, the ONLY way to tell if it's in the tank or in the plenum is with the shut off valve. Without the valve, you're guessing, and guessing gets expensive.

Ignition failures typically occur when the engine is hot, not cold. Fuel delivery problems typically occur when the engine is cold, not hot. Any way you look at it, it's got to fail when you have test equipment connected in order to find which system is at fault.

Well it did it again this morning. My last 4 days off it started for me but I guess it does not like where I park at work.
I just hope it continues to start until my next days off.