Starting problem

The fuel pressure should be 60-66psi when you turn the key On. Also test the CTS resistances hot and cold could be the trouble not running smooth before the 10secs.

This guide should help

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down this guide and report back.

The pressure is exactly 60 with the key on. Drops to 50-53 while running but will go back to 60 psi temporarily if you step on the gas. Is that normal?

I'm replacing the temp sensor and the fuel filter to see if there are any changes. If no change, I guess the fuel pressure regulator is next.

but will go back to 60 psi temporarily if you step on the gas. Is that normal? Yes

Is this the CPI Vortec -the regulator is under the intake manifold tuning valve-

The Spider is the little CPI injector with 6 little injector lines and poppets at the end of those lines....looks like a spider if you imagine hard enough.
There are 2 larger lines that connect to it also, they're the fuel supply and fuel return to the fuel tank lines.
If you take the top off the manifold, you'll find a puddle of gasoline. A puddle on the driver side is cracked fuel supply & return lines...the CPI is OK, buy a nut kit(which is what they call the fuel lines???)!
A puddle on the passenger side means the CPI regulator is bad but another regulator is available.

Turns out the fuel system was fine. After understanding how to do that part I decided to replace the ECT sensor first since it was so much easier. When I dug it out, I found the plastic connector base broken off and no electrical connection at all. The ECM didn't know the engine temp. Replaced that, and so far so good - perfect starting and no codes. Got lucky on this one maybe. Thanks for all the help.

Replace ignition coil and or modual with AC Delco parts. Problem solved

my GMC 1999 safari service van (work gave it to me, to get rid of it) will not start when it rains, i have replaced plug wires, distributor cap, ignition modual, and plugs, it turns over real easy and tries to start but it's like there is no spark to light the gas or something, i did have to have the steering column replaced, but that was all taken care of last year. any ideas to try next, i really need to get this van going it is my primary transpertation. and it has always been a real good starter no matter the weather,
and the engine is getting gas fuel is reaching the engine.

Did you visually check for spark at the plugs? You can pull a spark plug wire loose, use known good plug or spark tester in the boot. Ground metal part of plug/ tester to metal part of engine, watch for spark, engine cranking. Use a fuel pressure gage to check fuel pressure. Some of the national brand autostores used to loan out a fuel pressure gage.

Replace ignition coil and or modual with AC Delco parts. Problem solved.

Thanks for the input. That info will help others that find this post. Thanks for visiting 2CarPros.

I have starting problems under high humid and windy/misty rain conditions which usually is in the Spring and Summer.

try spraying ALL ignition parts with 'wire dry' or some silicone spray even wd40 stuff can work. this stops moisture from diverting spark to ground before it reaches plugs.

I had this issue of starting I'm damp conditions and found a cure online. Replace coil and or modual with AC Delco parts. Problem solved. I replaced both so I don't know which was faulty but I never had the problem again.

1999 GMC Safari All Wheel Drive Automatic 120 miles

Have there been problems with 1999 Safari not starting because of security system problems related to the remote??? I have had this happen and had it towed in only to have it start for the mechanics. But now it has happened again and i have been told it is related to the security and remote. Anything I can do on my own to solve the problem>?

When it doesn't start does the remote work like the unlocking of it?You said possible it was a remote problem so i was thinking maybe it wasn't unlocking with remote to disable the security?When it doesn't start does it crank no start or no crank no start?Also when it doesn't start is the security light flashing or on.Let me know.

I have a 99 as well had same prb, it was the battery cables i spent so much $ at mechanics they couldn't find the prb. it was like taking a sick child to the dr's they make a liar out of you!!! Hope you car figure out issues.

99 gmc safari was running great, now wont start. it will turn over but acts like there is no fuel. further, cant hear the fuel pump. is this a common problem.
is this a definite indication of a fuel pump problem or is there a module that could have gone bad?

A common problem, it sounds like your fuel pump has failed and needs to be replaced to be repaired. You can find a low cost OEM pump from amazon.com

depending on where you live and if you keep less than 1/2 tank of gas or lower you will get moisture buildup inside the tank. The metal parts get rusty and stick and then your pump will not work at all. I find this to be a common problem in my astro van. I have replaced it twice in 4 years. The first instance was caused in part however by the brand of gasoline I was using. Shell had put an additive into the blend of regular fuel that caused premature failure of fuel pumps. Only in Canada you say!!!
I highly reccomend you have a repair shop do this task.

1999 GMC Safari mileage: 98,000. The van’s alternator was diagnosed with a bad bearing. The battery has been replaced recently. The service engine light has come on occasionally and the van has hesitated. This morning the truck started and ran for five minutes. The engine was turned off and would not start again. There is now no interior lights or headlights or radio. Fuses are good. The engine will turn over, any reason why the truck will not start?

Your car is equipped with a computer controlled engine management system. An independent auto service center can scan your computer for fault or error codes. The information should pinpoint the malfunctioning components

my 99 safari will start w/ starter fluid, then idle no problem. When given any gas dies. Before doing this it ran great the one day backfired and died due to cap going bad ( has been replaced ). After that day will not start except with the starter fluid.

Thanks for any help

Do you hear the fuel pump come on when you turn key to run?-if so check the fuel pressure if its within specs if okay test the coolant temperature sensor and fuel pump and oil pressure sending unit-

engine turns but will not start

Cranks but no start condition:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem,Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

i have a 1999gmc sarfari 4.3 that will not start if it is raining starts fine runs good when it is not raining . will crank but will not fire . have replaced dist cap,rotor,ign module,spark plugs. by the time i get parts put it starts getting fire to plugs and starts.dont know where to go from here.

by the time i get parts put it starts getting fire to plugs

If you're getting spark-check if its getting the correct fuel pressure and injectors are pulsing-