Cranks but won't start.

[xpeachx]

Hello... I am new to the forum. I have had my 98 Bonneville SE for about 10 years now and for the most part it's been trouble free. About a year ago it over-heated and I've been having problems ever since. The problem right now is it cranks but won't start. I have recently replaced the battery, the starter, coil packs, plugs and wires, water pump, fuel filter and a few other parts.
It cranks good and sounds like it wants to start. I hear the fuel pump kick in when the key is turned on but it just won't start. With all the new parts it's been running good but one morning it just wouldn't start and I'm not sure what else to look for. Any insight would be greatly appreciated as I need my Bonne back. Thanks in advance.

[harofreak00]

Step 1 is determining if this is a fuel or spark issue.

Fuel:
Do you have fuel pressure at the fuel rail? Remove the black plastic cap from the Schrader valve and depress the valve with something small and be the judge of how much pressure is there. Does it spray out or just trickle? Watch your eyes when you do this.

Spark:
Remove the spark plug wires from the coils and have someone crank the engine while you watch the coils. Do they all have nice blue arcing?

Report back and we can go from there.

[xpeachx]

Thank you so much for the quick response and a place to start troubleshooting. I'll report back later today.

[xpeachx]

Ok... here are the results
Fuel:
After cranking the the engine, the fuel sprayed out of the Schrader valve a good 18 to 20 inches. Seemed like significant pressure.

Spark:
Each coil arced with the engine cranking but the arcing was not blue. it was more of a yellowish color.

[harofreak00]

Fuel at the rail is good, but injectors might not be firing.

Pull the plugs and see if they are wet with fuel. Maybe do a compression test while you have them out.

[xpeachx]

I'm guessing you have to remove the entire fuel rail to get to the injectors... right?

[95naSTA]

You don't need to in order to see if they're firing. Pull spark plugs to see if they're wet with fuel. Or pull an injector electrical plug off and fit a small bulb in the connector to see if it flashes when you crank it over.

[xpeachx]

Sorry for the delay in posting... I can't work on the car in bad weather (no garage)

Knowing that the injectors are at least 15 yrs old (if not more) I changed them out with new ones. No change... still cranks won't start. I don't have a compression tester so I couldn't test that. What's next? Junk yard?

[harofreak00]

No sense in asking for more help when you haven't done what we've already suggested.

Compression tester is $20 on Amazon or free at your local parts store rental program.

194 bulb to test injector pulse is less than $1.

[xpeachx]

Wow... I certainly didn't mean to offend anyone by changing out the old injectors. I bought them a year ago but never installed them. You mentioned they might not be firing so I installed them just to eliminate that possibility. I don't have another car so I have to get a ride to get parts. I'll get a compression tester... and do as you suggested but... "No sense in asking for more help when you haven't done what we've already suggested?" I don't think I deserved that...but I will apologize if I offended you. I'm just trying to get my car running... If you don't think I deserve your help I'll move on.

[harofreak00]

I'm not sure how to respond to that. We gave you several suggestions on what to do, you tried your own thing and it didn't work and then you asked "What's next?"

Just because the injectors are new, that doesn't mean they are firing. You need to check the injector pulse.

A compression test is just to make sure the engine is even worth saving. If you have no compression on any cylinder its scrap metal.