99 Tahoe no start, got fuel and spark

[chevy in my blood]

Trying to get my new Tahoe started. It's getting fuel pressure and excellent spark. I've tried a little start fluid in the TB but it still doesn't try to bust off, just spins. I swapped the ignition module and coil off a running truck and still getting good spark, but still no pop. The tech moves while it's turning, so I'm assuming the crank and cam sensors are fine. Also checked aux b fuse, its fine. Showing no codes when I hook the scanner up. Lastly the engine sounds like it's not turning over quite as fast as it should, and I'm hearing a low end clank with each revolution. That brings timing to mind. I'm gonna check that the rotor button is on it (I was told it was pulled but should have been put back on) anything else I should check?

 

[skylark]

Do you have spark at the plugs?

 

[chevy in my blood]

Do you have spark at the plugs?

I haven't pulled any plugs yet, got caught by the rain, but I pulled plug wires and they got excellent spark on the plug side.

I saw a thread earlier where someone had such bad plugs they wouldn't fire at all, it's on the list of things to check. Any other ideas?

 

[skylark]

Check spark on multiple plug wires.

 

[chevy in my blood]

Check spark on multiple plug wires.

I checked on 3 plugs, 2 on passenger side and #1. I'm going to try unplugging the coolant sensor as well, I've read here that it can cause a no start situation, worth a shot.

 

[chevy in my blood]

I should add that my scanner shows that it hasn't run the coolant sensor test yet, so idk. In fact it shows 48 codes not ran since codes cleared, and no codes current.

 

[SAATR]

What is your fuel pressure? These engines don't like to fire on less than 50psi or so. Pull your plugs and check to see if they are wet with fuel. If they are, you have enough fuel pressure to fire the injectors, so that shouldn't be an issue. You'll need to clean them with some solvent and compressed air if they are fouled, or at least leave them to air dry for a bit. Good spark in the open air doesn't necessarily mean good spark under compression in the combustion chamber. I've seen more than a few of these engines with what appeared to be good spark that wouldn't start due to poor contacts and fouling on the cap and rotor. They are a known issue on these engines and should be changed if there is any doubt whatsoever. You wouldn't have spark at all if there was no rotor present in the distributor. Ignition timing could be way out if the distributor was pulled and put back in. You may need to roll the engine to TDC on cylinder 1 compression stroke and verify that the rotor is pointing toward cylinder 1 on the cap. That will put you in the ballpark, at least close enough to make an attempt to start. Lastly, if all else fails, check compression. It's possible that your engine's cam timing is off due to a slipped timing chain. It's not common, but possible.

I'm betting on low fuel pressure or an ignition issue, myself.

Sent from my XT1585 using Tapatalk

 

[chevy in my blood]

If fuel pressure was my problem it would at least pop or try to start when i use start fluid. Don't have a fuel pressure gauge til later this week but It doesn't do anything, it acts just like s no spark issue, and believe it or not, I have seen an engine run without a rotor. It was a Ford v6 in an 88 ranger. It ran absolutely horribly but it ran. Thought you might enjoy hearing about that lol. I'm going to pull the plugs today and do a compression test, as well as checking the timing. Though the distributor has never been out of it, so unless it has jumped time it should be perfect. Let's hope that's not the problem lol.

 

[chevy in my blood]

I'm about to go work on the Tahoe. Will also be checking for a passlock problem. I delt with it once in my cousins 02 Chevy pickup. His would attempt to start though or start and then immediately die.

 

[chevy in my blood]

Verified that the coolant sensor is not the issue, and the security light is not flashing so it's not passlock. I'm gonna pull the plugs shortly and the dizzy cap. I've already checked the the cap is tight and not moving. It still sounds like it's not turning over fast enough. I put a magnetic reduction starter on it, where it had a direct drive starter before. Could this be the reason it's not turning over as quickly as it should?