I recently had my radiator fixed, and after I re-installed it, it ran a bit hot. Well I fixed the running hot issue (apparently I had not "bleed" the radiator right), and now it has a hard time starting in the morning. Once it gets started and going, it will crank right up all day. I have tried pumping gas into the motor when starting, and it does work sometimes, but it is backfiring and "dieseling" after I let off the key when it doesn't want to start. I have been told fuel filter, this, that and I have even though it was the coolant temp sensor, (I had a gf with a Saturn that did the same thing, and the sensor was sending -30 degree readings to the ECM). I am at a loss for this problem, as a ODB scan tool is telling me nothing but a O2 sensor (which has been bad forever and I am just too lazy to fix it, and too cheap to have it replaced), but it has had that problem and never had a problem starting. Does anyone know for sure what it is??? I do have a problem with rough idle when it first starts, but it goes away with some road mileage. The only thing I am behind in (as far as Preventive Maintenance) is my tire rotation. Please someone help, mine has 286k miles, and I want to drive it beyond 400k.........

 

Still on the original fuel pump? Might wanna check fuel pressure.

 

Fuel pump???? not to second guess you, but would it not happen at other times???? I thought when a fuel pump goes, it goes out no matter what time of day it is- I.E.- Would not start any time of day, or shut the truck off going down the road...... I will get a shop to check the pressure level of it. Can I buy a gauge kit to put on there so I can see it myself?

 

Yeah you can buy a fuel pressure gauge pretty cheap. When the pump was going out on my Blazer it didn't want to start sometimes when the engine was cold- up until it just completely went. I would definately at least check it. How are the plugs? Cap/rotor/wires? From what I've read the fuel filters are not serviceable on these trucks. Basically replace it when you replace the pump.

 

There are any manner of gauge you want to stick on there. Keep in mind though, that it is illegal to plumb fuel into the passenger compartment, even for just a gauge. (really not a good plan in any event.)

There ARE electric fuel pressure gauges though.

The pump also has a drainback valve in it. If the valve has failed, when you shut the truck off, it allows pressure to bleed off. Yours hasn't gone completely it would seem, but, is prolly on it's way out.

Low fuel pressure will make the truck hard to start, and it WILL run rough in open loop, once it starts paying attention to the O2 sensor though, the computer can compensate, to an extent.... for low fuel pressure. There comes a point though, that the computer will no longer be able to do so..... and the truck will just run bad all the time, if it will run at all.

There are many different failure modes for fuel pumps. Ranging from all at once. (truck just quits, and that's it, yer done.) to slowly 'getting tired' over time. (parts wear, and it just can't create the pressure that it once did.) and anything in between.

Check fuel pressure, also check how fast it bleeds off once the engine is shut off.

 

lol, yeh i know fuel vapor in the cab of a truck is bad (i was hoping you might know of a small gauge i could mount under the hood, and check it when i have this problem.)

can i use some spray starting fluid for a week or so??? with this economy, and it being first of the month, i am poor as a church mouse.

 

Try this just for an experiment.

First thing in the morning, when you go out to your truck, turn the key On, but DON'T try and start it, listen for the fuel pump to run. When it stops, turn the key off for a couple seconds, then cycle back to on. WHen the pump quits, turn the key off for a couple seconds, and THEN try and start the truck. It should fire right up.

 

As it is Sunday morning, and I have not yet fired up my truck yet........ This is a great time to try this. What should I listen for??? Is the fuel pump easy to hear??? Do I need to crawl under the truck at the tank to hear it???? Just asking so I know for sure how to do this.

Also, thanks to you for your help, along with anyone else that has commented.

 

@SilverSS..... the plugs and wires have a bit of mileage on them, but they were changed out earlier this year (around march-april). The wires show no signs of cuts, burns, breaks, etc..... I have not yet pulled the plugs, as it does not seem to have a miss or a problem relating from bad plugs.

 

@heyyou............ your trick did not work, but i do have other important symptoms that might help you to help me.

after i tried to start it for the first time, i let off the key and it seemed to "diesel" a few puffs and stopped. i also noticed a bluish cloud, and it smelt very much like gasoline. after finally putting the accelator pedal down while starting it, it finally caught. i went to my local gas station for a pack of smokes, and when i started the truck for the return trip home, it fired right up. the store is only 2-3 miles, at the most, one way.

my idle seemed a bit higher than normal (bout 700 rpm in drive), but it was fairly smooth.

does that help you out any???? I am still leaning towards a choke problem (Idk if it has a electric choke or is it some sensor), but it just does not seem to get any air into the cylinders first time it starts up.