97 blazer

[zanerat]

My 97 cranks but wont start. It will not start with carb cleaner. This started as a intermitting problem some times it would fire and run great sometimes it would be hard to start and engine would surge a little going down the road.

[MT-2500]

Originally Posted by zanerat

My 97 cranks but wont start. It will not start with carb cleaner. This started as a intermitting problem some times it would fire and run great sometimes it would be hard to start and engine would surge a little going down the road.

Does it have good spark to all plugs when no start?

What is the fuel pressure when no start?

Any check engine lights or security code or engine running codes?

How many miles on tune up?
Good Ac delco plugs?

Remember 97 is a bad year on ign switches.
May need proper testing on that.

Tape a fuel pressure gauge to outside mirror or outside windshield.
The only true test on a fuel pump is to check the starting and engine running and check fuel pressure after 30 minutes drive and also direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold or hot and fuel pressure testing guide lines.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.

[zanerat]

I have checked all the fuel stuff all seems to be in check. I kind of feel that it has a week spark the engine seems to be flooding strong smell of gas at the tail pipe. I am just uncertain how to check the ignition components

[MT-2500]

First check for good hot blue spark at plugs and out of coil.
Spark should jump over 1\4 in and have a good loud blue snap to it.
Get a spark gap jump tester or grouud it out with a screw drive.

Post back your fuel pressure readings.
Did you check fuel pressure when no start?

[Darren509]

I have a 97 jimmy that wouldnt start either, prior to that it was getting hard to start when cold. Ended up being the cheap cap and rotor I put in less than a year ago. Bought AC Delco cap and rotor and fires up instantly now.....

[zanerat]

Ok I have checked fuel pressures everything good wont even hit on carb cleaner. I have checked the big pink wire in the steering colomn it has 12 volts. My spark to the plugs seems to be very weak dont know what to do next

[zanerat]

I would like to properly diagnose the ignition switch can anybody help

[MT-2500]

Originally Posted by zanerat

I would like to properly diagnose the ignition switch can anybody help

What was the fuel pressure reading you got?
To check switch.
Get a good wiring diagram and check for power into switch and for power out on all power feeds.

[mike2004tct]

Originally Posted by zanerat

I would like to properly diagnose the ignition switch can anybody help

Read thru this thread from a few weeks ago. The importarnt stuff is at the end of the thread (page 2 & 3)

12V on the wire doesn't mean much. It brings power to the switch. It's what's inside the ignition switch box that matters. 12V in, but no 12V out.
Does you dash light up?


http://www.automotiveforums.com/vbul...d.php?t=974363

[zanerat]

Thank You all very much I found the culprit cap and rotor

[Darren509]