I have a 2000 chevy trailblazer package With the 4.3 liter v 6... I have owned this little truck now for 5 years and I love it..... I am a commercial fisherman so of the 160,000 miles that it has on it 125 of them have been with a 21 foot carolina skiff strap to the back of it but now I'm having a problem that is frustrating...... it simply will not start in the morning.... the only thing that will get it running in the morning is a shot of starting fluid, we have checked the camshaft sensor, the crankshaft sensor, the spider module, and the power control module... the fuel pressure at the intake hold steady at 44 psi when the fuel pump primes..... a friend of mine told me that the injectors will not fire unless it has at least 50 psi at startup........ but I don't really know what to think because I have a hard time believing that the truck will run fine once it has started but not start without a higher pressure....... any help with this would be greatly appreciated.... it's becoming very tiresome to have to pop the hood every time I wanna start the truck!!!!!!!!

 

i got a 95 blazer 4x4 and i got the same problem, i cant figure it out either. .. mine will start but it takes like 5 times to get her going. only when cold.

i changed coolant temp sen. all new ingintion (coil, ing mod, wires, dist, cam sen, cap and rotor,).

this started just after i fixed my fuel line leaks in the intake.

after its warm it starts right up.. i don't get it either. it runs great no a missfire or anything. purrs like a kitten and it will start every time when its warm.

i was getting a heater o2 malfunction so i changed them.. it did nothing. just a waist of money..

i have no check engine lights all new sensors, all new ingintion.

to me it seams that a sensor it not letting it get fuel when its cold. i just dont know witch one controls that. i thought it would be the o2 cutting fuel cause of heater issue.

if i find out what it is i deffently spread my wisdom. or if anyone else can help us on this problem would be sweet...

update:

i have 62psi on first prime. and it holds it. but still no start. i know u said that it was 44psi. that's kinda low.

have u changed your fuel filter lately... i changed mine and got 5psi more. but it didn't help with my cold staring thou .

 

Yes I changed my fuel filter And that did make a difference on the power and responsiveness when the engine is running But it did not help with the cold start problem!!!!!

 

i dont know if this will help but i had the same problem with a vehicle of mine it is not a blazer but it was a 1989 toyota 4runner what i had to do to get mine to start in the cold was get a hair dryer and heat up the cold start plug once it was warm it started great the rest of the time now iv been to part stores and have been sold bad sensors so if your sensor is still under warrenty id get another just to see if that does anything well maybe that will work hope you get it running.

 

thanks dillon but we dont have those on these, but its a similar in what a coolant sensor does..

its a trick i might try. the hair drier. have tried everything else except change the fuel pump or the spider assembly... i don't want to waist anymore money or time on this truck. i just want this damn thing to start. it getting colder out.

the coolant sen is new but what the hay ill try another.

and yeah i'm getting tired of popping the hood as well. my cable has about had it

 

well your fuel pressure is a few psi short thats for sure, But all the times i have seen this happen on vortec motors it has been the injector setup. The same thing happened to my blazer,bravada my buddies blazer, jimmy-envoy& a few customers s-series it always seems to be the injector setup really only takes maybe 2hrs tops to pull the upper intake off swap the injectors throw new gaskets on the plenum, and put it back together. Here is a link to the fuel issue https://blazerforum.com/forum/tech-articles-diy-29/96-fuel-system-diagnosis-23038/ you should be able to fix your problem from that link, because your fuel pressure is only 44psi i wonder if your pressure gauge you are using is right, because usually when its that low a shot of ether does not do the trick to get it runnin fine.

 

Fuel pump should be putting out appx. 60 psi at the intake when primed. Its most likely either the pump or the spider or both.

 

Hey Netslinger,

I just resolved what sounds like a very similar problem. It was the fuel pressure regulator on my 98 S-10 with a 4.3 Vortec. It was not starting. I'd jump it (basically just run it for a while with the starter) for the first start of the morning and it would be good (or what I thought was good) for the rest of the day, providing it didn't sit for more than 4 hours and become cold again on a 20-40 degree F day.

I measured the fuel pressure and was getting around 45 psi at cold start.. (this is indeed low) as it should be 55-61 psi. I'd eventually get it started and it would run at around 54 psi and higher under load, this is according to spec... Strange, so my fuel pump appeared to be okay (replaced it about 4 years back). The symptoms pointed to the Fuel Pressure Regulator... The most stupid little part about these motor's fuel injection system. It's on the back of the spider under the upper intake manifold, has no tubes as it just uses the vacuum inside the plenum.

Its about $50 at Autozone and took me about 3 hours (first time working on anything but spark plugs on the engine for me) you'll probably be able to get at it quicker. Got everything hooked back up and the s10 starts like a champ. Probably could have gotten by with cleaning the old one as it was covered in carbon deposits. But I put the new one in and emptied a can of carb cleaner in the intake to clear out some of the gunk.

this thread has some pics in it that are pretty decent



I hope this helps someone.