02 S10 starting problem

[DAVEQ]

I have had this problem twice in the last week . It cranks and will not start , when i release the key from the crank position to the run position it fires a few cylinders and dies . Fuel pump was replaced less than a year ago with a good quality pump and it is running . It eventually starts after lots of cranking and patience and runs fine , it has never died on me while driving it also . Any ideas would be appreciated , thanks .

[MT-2500]

Originally Posted by DAVEQ

I have had this problem twice in the last week . It cranks and will not start , when i release the key from the crank position to the run position it fires a few cylinders and dies . Fuel pump was replaced less than a year ago with a good quality pump and it is running . It eventually starts after lots of cranking and patience and runs fine , it has never died on me while driving it also . Any ideas would be appreciated , thanks .

First idea=.
Fuel pressure low?

What engine?
What brand was that good quality pump?

You need to check and confirm good fuel pressure up to specs and good spark when cranking.

[NHRA]

also might look at the control module

[DAVEQ]

Ok finally getting back to respond . I replaced the fuel filter and it ran fine until last week , it died and has not run since . The fuel pump replacement was an Airtex which I have not heard anything good about . The pump runs when I turn the key on for 2 seconds , tomorrow I will check the fuel pressure when I pick up a gauge kit to test it . It has plenty of spark when cranking but will not start when I trickle gas into the butterfy or give it a shot of ether which I don't understand . How much pressure should I have whith the key on and while cranking ? . Also it pulls no codes on my scanner .

[MT-2500]

Originally Posted by DAVEQ

Ok finally getting back to respond . I replaced the fuel filter and it ran fine until last week , it died and has not run since . The fuel pump replacement was an Airtex which I have not heard anything good about . The pump runs when I turn the key on for 2 seconds , tomorrow I will check the fuel pressure when I pick up a gauge kit to test it . It has plenty of spark when cranking but will not start when I trickle gas into the butterfy or give it a shot of ether which I don't understand . How much pressure should I have whith the key on and while cranking ? . Also it pulls no codes on my scanner .

What engine?
The below checks and test are for 4.3 V6.
If 4.3 you need 63-65 lbs of fuel pressure to squirt injectors on a cold start.
If pump and regulator and fuel line good you should see 65-66 cold cranking.
And 100 lbs with return blocked off.
And always check for fast leak down pump off.

Pitch that starting fluid or you may blow the dip stick threw the hood.
Only use carb spray as a starting aid.

If good spark to all plugs and timed right it should fire on carb cleaner.

Where are you checking for good spark?
If not at plugs check there at all plugs.
Is the dist rotor turning when cranking engine?

Post back your fuel pressure readings.
Key on prime up and cold cranking.
And with return line plugged.
Or ditrect fuel pressure at fuel filter in line.

[DAVEQ]

Engine is a 4.3 . Fuel psi with key on is 62-63 lbs and 65 psi when cranking . Not sure how or where to block off return line to check that way , fuel psi. does not bleed down after 5 mins. or so . I also replaced the ignition control module today and another dist. cap , still won't fire . I am checking the spark at the plug wire with a plug in it and it sparks fine so rotor must be spinning . Also tried carb cleaner down the butterfly today and nothing . It has plenty of power when it was running so the engine is not low on compression from to many miles on it . What about a stuck open EGR valve ? , running out of ideas here and going crazy . Dave

[MT-2500]

Originally Posted by DAVEQ

Engine is a 4.3 . Fuel psi with key on is 62-63 lbs and 65 psi when cranking . Not sure how or where to block off return line to check that way , fuel psi. does not bleed down after 5 mins. or so . I also replaced the ignition control module today and another dist. cap , still won't fire . I am checking the spark at the plug wire with a plug in it and it sparks fine so rotor must be spinning . Also tried carb cleaner down the butterfly today and nothing . It has plenty of power when it was running so the engine is not low on compression from to many miles on it . What about a stuck open EGR valve ? , running out of ideas here and going crazy . Dave

Check more than on plug for spark.
You can have spark at/from coil and spark not going to or threw dist cap or dist rotor may not be turning.
Even coil wire can be bad.
Check all is better.
Make sure dist has not jumped time.
Does no one plug spark ao TDC compression.
And do not rule out copression.
Does engine have vacuumn cranking?
To check EGR valve remove it and check it.

[DAVEQ]

I checked #1 and #2 for spark at the plug ( front cyl. on each bank ) and both are fine . Rotor is spinning for sure , new plugs and wires also . I really don't think the distributor has jumped time , it ran fine when I drove it home and shut it off but I will verify that .