Help! 1999 Chevy Tahoe no start issue!

[Sammie859]

This is what Goodyear gave me! They said it past a spark test But no tach signal? What’s that even mean?!

 

[YukonGTmaster]

I would hope that Goodyear would have verified that your Top Dead Center Mark, and your Rotor in your distributor were properly aligned, and that your plug wires were all correct before doing the “Spark Test”. I am baffled why they would not replace the Cam Position Sensor to clear your P0340 code. I feel that a no Tach Signal (RPM needle not moving on the dash) could be from one of these sensors not sending its signal. Going to a GM dealer may give you piece of mind that their Techs have the experience on these vehicles at this point.

 

[iamdub]

This is what Goodyear gave me! They said it past a spark test But no tach signal? What’s that even mean?!View attachment 348429

Check the connector on the ignition control module. It's mounted next to the coil. It's been YEARS, but I believe the tach wire is white. Although, I'm wondering how it would pass a "spark test" if the CMP sensor or ICM were faulty.

Do you have it back in your possession? Have you checked the points mentioned so far?

 

[OR VietVet]

The ignition coil has wires from it that go inside that distributor. I would check the wires from coil to the distributor and make sure there is no damage. I would also check the coil and coil wire to see if anything is amiss. I am still convinced that the cam sensor is the problem but is really best to have a qualified tech look at it.

What Is The Cause Of P0340?​

• A defective camshaft position sensor
• Damaged or dirty reluctor ring on the camshaft
• Defective, corroded, shorted camshaft position sensor circuit wiring
• Defective, corroded, shorted camshaft position sensor circuit connector
• A faulty crankshaft position sensor
• Stretched or misaligned timing components
• ECM software update needed
• Faulty ECM

 

[TollKeeper]

This one baffles me.. How can it have spark, but no tach. You cant have one without the other as far as I know. This has a very straight forward DIS system.

So the easiest route at this point is to replace the ICM. I believe for your truck, its part #19352931 ACDelco. This will take a average mechanic about 30 minutes to change.

While the cap is off, have someone turn the key on, and turn over the truck. This is just to verify that the cogs on the crank and distributor are still working, and spinning the distributor.

But this is not guaranteed to fix the problem. Your problems started after you replaced the Crankshaft Position Sensor. So this is still highly suspect.

What brand and part # was used for the Crankshaft Position Sensor? This has been asked a few times, and still not answered.

What @PNW VietVet said also hold a LOT of water. The wires going into/to the distributor are a KNOWN failure point for the 4.3, 5.0, and 5.7.

 

[exp500]

Is there an independant repair shop near you? Some areas have mobile mechanics that are reasonably priced. Did goodyear change injectors?
The Diagnostic I provided will lead to a fix in 30 minutes.

 

[Sammie859]

Check the connector on the ignition control module. It's mounted next to the coil. It's been YEARS, but I believe the tach wire is white. Although, I'm wondering how it would pass a "spark test" if the CMP sensor or ICM were faulty.

Do you have it back in your possession? Have you checked the points mentioned so far?

I just got it back late yesterday. So today I’m going to check the wires from the distributor. Check the ECM plug. I’m just confused! ‍

 

[Sammie859]

This one baffles me.. How can it have spark, but no tach. You cant have one without the other as far as I know. This has a very straight forward DIS system.

So the easiest route at this point is to replace the ICM. I believe for your truck, its part #19352931 ACDelco. This will take a average mechanic about 30 minutes to change.

While the cap is off, have someone turn the key on, and turn over the truck. This is just to verify that the cogs on the crank and distributor are still working, and spinning the distributor.

But this is not guaranteed to fix the problem. Your problems started after you replaced the Crankshaft Position Sensor. So this is still highly suspect.

What brand and part # was used for the Crankshaft Position Sensor? This has been asked a few times, and still not answered.

What @PNW VietVet said also hold a LOT of water. The wires going into/to the distributor are a KNOWN failure point for the 4.3, 5.0, and 5.7.

Idk what brand was used. My husband bought it a couple of months ago and doesn’t remember where! ‍ (I hold receipts forever, he therefore doesn’t!) also, he’s never dealt with a vehicle that has a distributor and isn’t mechanically inclined before that gets brought up. He can do the basics (oil, brakes but that’s it)

 

[Sammie859]

I would hope that Goodyear would have verified that your Top Dead Center Mark, and your Rotor in your distributor were properly aligned, and that your plug wires were all correct before doing the “Spark Test”. I am baffled why they would not replace the Cam Position Sensor to clear your P0340 code. I feel that a no Tach Signal (RPM needle not moving on the dash) could be from one of these sensors not sending its signal. Going to a GM dealer may give you piece of mind that their Techs have the experience on these vehicles at this point.

Im Not completely sure what they did, according to the report, not much. They said they tried to swap the relay (nothing changed) and they tested for spark and it passed. But they didn’t say where they tested for spark or would that matter?

 

[Sammie859]

I just went out to roll my driver window up. Apparently tow truck left it down. When I turn the key over to acc these lights are on (battery and check gauges) those weren’t there before.