99 Burb intermittent start

I have a problem that has been with us ever since the extended warranty expired (go figure). The problem is intermittent and the vehicle is close to the 100K mark. Sometimes it will start and other times it will just crank but sounds as though it is not getting spark or fuel.

I have changed the spark plugs, fuel pump, and the positive battery cable and have swapped the fuel pump relay. The fuel pump occasionally does not whine when shutting off and then trying to restart within a few seconds.

Is there a way to check the fuel injectors without expensive equipment? I am an aircraft electrician so I am pretty good at electrical troubleshooting. I just don't know what to look at since I only have a Chiltons.

How can I check to see if I am getting good spark?

Any other ideas?

Thanks

Intermittent problems are the worst...

I think you can check the injectors with a 'NOID' light. Not expensive. Just about every shop/mechanic has a set.

Checking spark can be done the old fashion way with a screwdriver. A trained eye can 'see' when you have a good spark. A regular spark tester can also be used.

Check all connections and grounds.

If The Engine Cranks And Will Not Start, It Will Not Be The Fuel Injectors. The Only Problem With That Style Of Injector Is Getting Clogged. This Condition Causes Running Rough Upon Cold Start, But Not A No Start Condition. As Far Is The Fuel Pump Not Winning After Ignition Is Turned Off And Then Back On, This Is Normal Due To The Fuel System Already Has Its Prim. The Most Likley Causes For This Year Modle Would Be The Ignition Switch Or Loose Contact At The Fuel Pump. Did The Condition Start After The Fuel Pump Was Replaced? Also When This Occurs Look And See If The Prnd321 Pintle Light Is Illuminated. If The Prnd321 Is Not On This Is A Comon Ignition Switch Issue. Also Double Check The Positive Battery Spacer And Bolt For Corrosion Or Being Loose. Excuse My Spelling

Thank you VERY much for the responses.

The truck has always had a light stumble at idle. The dealership could never find anything wrong, but recomended a top clean.

The problem just appeared all of a sudden.

I will double check the battery terminal, but I am positive (pun intended) that this will check good. I had just replaced the entire cable and the engine cranks fine. Just doesnt start.

i will also check the Gear shift light.

thanks again. I will keep you posted.

i had the same problem on my 99 gmc suburban..
took me losts of time and money... It started when ever it felt like and didnt when ever.. the dealer couldnt figure it out cause it wasnt doing it as it was there... however the prob was the harness that connects the the fuel pump. i replace my fuel pump and thought that was going bad. twice i did that cause when i check the harness it always had power.. the probe that stick out of your ac delco mu152 pump does not make a soild contact with the harness.. so i got a lil presision screw driver and bent the contact pionts back enough so i makes a solid contact at all times..



try this!!!

lol on a empty tank :=)

An empty tank is a good idea, but I changed my pump VERY carefully filled with 40 gallons :screwy:. A tranny jack worked flawlessly :icon16: . I will also give the contacts a try.

If The Engine Cranks And Will Not Start, It Will Not Be The Fuel Injectors. The Only Problem With That Style Of Injector Is Getting Clogged. This Condition Causes Running Rough Upon Cold Start, But Not A No Start Condition. As Far Is The Fuel Pump Not Winning After Ignition Is Turned Off And Then Back On, This Is Normal Due To The Fuel System Already Has Its Prim. The Most Likley Causes For This Year Modle Would Be The Ignition Switch Or Loose Contact At The Fuel Pump. Did The Condition Start After The Fuel Pump Was Replaced? Also When This Occurs Look And See If The Prnd321 Pintle Light Is Illuminated. If The Prnd321 Is Not On This Is A Comon Ignition Switch Issue. Also Double Check The Positive Battery Spacer And Bolt For Corrosion Or Being Loose. Excuse My Spelling

This sounds like my current problem. When you say ignition switch are you refering to the actual part that the key goes into? And my Prnd321 Pintle Light is permanently on and I can't get it off. Please help.