Cranks but won't start
- Thread starter Dave347
- Start date
Uhgg. Why doesn't my stock gas cap fit onto the new
Everything is completed. This was much more challenging then expected.
It fired right up.
Here's the tank reinstalled. (Next, I want to rebuild that driveshaft.)
It fired right up.
Here's the tank reinstalled. (Next, I want to rebuild that driveshaft.)
I put $20 worth of gas in the tank and went to the store. It was a short trip. When I got home, the needle was on empty. I don't see or smell gas anywhere.
This morning I started the TB and the needle went right to half full. It stayed there for a minute then went right back down to E.
Fuel Gauge & Sending Unit Troubleshooting
This video will help you troubleshoot your fuel gauge and sending unit, to verify if it is good or needs to be replaced.
www.americanautowire.com
There is a PID for fuel level. Got an OBD dongle? Could quickly tell if it's a stepper motor or the sensor signal.
I am running into this same issue with a 2002 Envoy.
I have replace the ignition switch, fuel filter, fuel pump, vapor canister vent valve, vapor canister purge valve, and spark plugs.
The spark plugs had a gap issue due to the tip being gone. I have 55PSI near the filter at least, and it stays at that all the time. It even started for about a minute or two after changing the pump, but since that it would not start. It even starts with starting fluid.
What else could it be?
Edit: I forgot to say this. I have gone thru all the fuses and relays in the one fuse panel.
I have replace the ignition switch, fuel filter, fuel pump, vapor canister vent valve, vapor canister purge valve, and spark plugs.
The spark plugs had a gap issue due to the tip being gone. I have 55PSI near the filter at least, and it stays at that all the time. It even started for about a minute or two after changing the pump, but since that it would not start. It even starts with starting fluid.
What else could it be?
Edit: I forgot to say this. I have gone thru all the fuses and relays in the one fuse panel.
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My immediate guess is that your new pump failed after only 2 minutes. Some pumps are very inexpensive, and some are about $250. What pump did you install?
I watch a guy on youtube and he installs nothing but the cheapest parts on his Trailblazer. It's hard to understand why he'd go that route, but I think he's a car "flipper" at heart.
I watch a guy on youtube and he installs nothing but the cheapest parts on his Trailblazer. It's hard to understand why he'd go that route, but I think he's a car "flipper" at heart.
I know it was not the cheapest pump and not the most expensive pump, but this could be the last winter for it due to rust, AC, and ABS issues. It was hard to know after this winter tho.
I know this is off topic, but they could be help with this issue too. I am not sure tho. If you want to know, we are running around in circles for those AC and ABS issues too. Last year, both of these issue started really bad.
We can not find any issues in AC system, but the AC just blows hot air on the hottest days. At the start, it works in temperature in the 80's or less. It was very random anything above the 90's. We have even took it to two different shops, and they can not find an issue too. One shop thought it was low pressure sensor issue that these SUV's has, but it was not that tho. If you want to know what I am talking about, look up TSB #03-01-39-007. Since that shop, the randomness disappeared, and the AC only works at 70's and lower, and nothing but hot air above 80's. So we are mainly using this Envoy on days that we do not need the AC any more unless we have to use it.
As for the ABS issue, it has been mainly left front wheel right now. We fix the rear ABS issue that we was running into which was rear upper control arms was rusted thru and was broken. We finally tracked it down to the front ABS issue to rust too which we was going to fix this year till this no start issue popped up. We even have all the parts for the front too.
You're right, it is. Please start another thread for each issue.
Yea, I thought so.
Back on topic, my friend and I did something very random even tho it was about half a tank. We drained the whole tank and even purged the fuel rail by the return line. While doing this, we smelled gas at times, smelled bad gas, and even smelled nothing. So we are thinking that water or bad gas. Then filled it back up to a quarter tank by gas can, and guess what.
It started right up and runs great.
Just need to weld the small whole in exhaust since it sounded like it could have been a plug up cat at times too.
So the TB ran perfectly for 2 weeks and then it happened again. More "crank but no start."
At least it broke down in my driveway and for that I'm grateful.
I tried all the old tricks and nothing worked. I disconnected the battery for awhile and also pulled the relay over night. These tricks worked before but not this time.
Then I let it sit for a week, and still it wouldn't start. Then it started for about 1 second. I switched a couple relays around and it fired right up. I switched the relays back to the original order and again it fired up.
At least I was able to pull it into my garage.
How do I track down this electrical gremlin? Because the fuel gauge was acting erratic after the pump install, I'm thinking that I might need a new pump harness.
At least it broke down in my driveway and for that I'm grateful.
I tried all the old tricks and nothing worked. I disconnected the battery for awhile and also pulled the relay over night. These tricks worked before but not this time.
Then I let it sit for a week, and still it wouldn't start. Then it started for about 1 second. I switched a couple relays around and it fired right up. I switched the relays back to the original order and again it fired up.
At least I was able to pull it into my garage.
How do I track down this electrical gremlin? Because the fuel gauge was acting erratic after the pump install, I'm thinking that I might need a new pump harness.
Perhaps you have an issue under the fusebox where the FP relay connects?
If that was the case, it would crank but not start unless it's shorting and blowing the fuse, which doesn't seem to be the case.
Edit: The pump had its own fuse so even if it did blow would not stop it from cranking.
No, there is no fuel pressure. I don't hear the pump running so that means no pressure.
Yes, it starts with a puff of the starting fluid.
Yes, it starts with a puff of the starting fluid.
Is jumping power to the fuel pump by bypassing the relay (confirm power then jumper #87 to #30) among the old tricks?
No, when this "crank no start" first started happening, I would disconnect the battery for 15 minutes or pull the relay overnight, and then the pump would work again. I tried those tricks, this time, and nothing seemed to work. Who really knows what was going on.
I haven't tried jumping or testing the voltage at the relay contacts. That's what I like to get into now. (Inspecting and trouble shooting the electrical system.)
It's been sitting right here for 5 weeks. I don't know where to start on this project. I feel like I need a trouble shooting guide. Starting with the fuse box back to the fuel pump.
Small Suggestion...
Having seen the amount of Rust Scale underneath your SUV... Trace the Ground Wiring from the Fuel Pump back to where it either attaches somewhere on a "B" Post or somewhere on the Engine Block and perform a De-Scaling R&R down to "Bright Steel" and apply some Dielectric Grease to those places prior to re-attaching the Bonding Wire(s).
Then Try and Start it up... and if She Does..."Giver the Beenz..." But Please... Open the Garage Door FIRST... We like you and want you to STAY ALIVE, Brother! :>)
If you have the Fuel Pump Wiring Diagram fro the 2006 4WD 4.2L Trailblazer-Envoy... and can figure out what G-XXX Numbers are for the Grounds... These Ground Location images from @Realism will show you where to put in the labor for their R&R and Clean Up:
gmtnation.com
Having seen the amount of Rust Scale underneath your SUV... Trace the Ground Wiring from the Fuel Pump back to where it either attaches somewhere on a "B" Post or somewhere on the Engine Block and perform a De-Scaling R&R down to "Bright Steel" and apply some Dielectric Grease to those places prior to re-attaching the Bonding Wire(s).
Then Try and Start it up... and if She Does..."Giver the Beenz..." But Please... Open the Garage Door FIRST... We like you and want you to STAY ALIVE, Brother! :>)
If you have the Fuel Pump Wiring Diagram fro the 2006 4WD 4.2L Trailblazer-Envoy... and can figure out what G-XXX Numbers are for the Grounds... These Ground Location images from @Realism will show you where to put in the labor for their R&R and Clean Up:
Electrical Ground locations
While troubleshooting a bad ground I came across some scans of the service manual regarding electrical ground locations for our platform posted on another site. This includes both short and long wheel base, as well as both 4.2L and 5.3L. Credit goes to Wex...
gmtnation.com
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I don't understand why, the pump never quits when your driving around. But it only fails when the engine is off, and your cranking it, trying to start the engine.
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that's likely because when it is being driven / running, the voltage is higher (because of the alternator) which "breaks thru" any poor contacts and / or weaken pump. You can do a simple test to check the pump circuit... pull the fuel pump relay and do a resistance measurement from outgoing pin / connection (towards the pump) at the relay socket to a KNOWN ground (ie. battery negative). Make note of the resistance. IF and when you ever get it running... do the same test again as soon as you stop the vehicle. Compare the results and go from there.
It's run the last 2 times I got behind the wheel. Right before it started giving me trouble again, I filled the gas tank. I don't want to drain all that gas, and I don't want to try lowering a full tank either. So I've been starting it, taking it for a ride, and then bringing back home. Trying to empty the tank.
That looks like the ground for the EBCM. Known to cause trouble. TSB for some years directs the repair to remove and discard the terminal and install a new terminal and hardware presumably more corrosion resistant.
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Aft of that bracket, there's an identical type ground attached to a body mount bracket (about right between the two doors.) It's close to the gas tank; what circuit is that ground used for?
Wait a second,,,AND the fuel pump relay????
Wait a second,,,AND the fuel pump relay????
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Yup... It goes something like this:
(1) "It's Bizarre... The Engine shuts off whenever I use my Left Turn Signal."
(2) "Whenever I turn on my Headlights, they flutter for a moment ...and then the Motor Dies."
The Stalling happens because these two Different Circuits try drawing so much power and amperage to overcome the electrical resistance from the poor grounding at the G-107 position on the Engine Block that the Fuel Pump Relay is also sharing at the very same time, causing it to drop out. Thus, the Fuel Pump shuts off.
If the location you asked about is on the "B" Pillar... it could be for THIS one... the Body Control Module Grounding Circuit as shown in THIS BCM Diagram as G-302:
To make certain, just take a second glance back at Post #143 for the Link to @Realism 's Brilliant Pictorial Collection of where ALL the Ground Locations are situated... ;>)
(1) "It's Bizarre... The Engine shuts off whenever I use my Left Turn Signal."
(2) "Whenever I turn on my Headlights, they flutter for a moment ...and then the Motor Dies."
The Stalling happens because these two Different Circuits try drawing so much power and amperage to overcome the electrical resistance from the poor grounding at the G-107 position on the Engine Block that the Fuel Pump Relay is also sharing at the very same time, causing it to drop out. Thus, the Fuel Pump shuts off.
If the location you asked about is on the "B" Pillar... it could be for THIS one... the Body Control Module Grounding Circuit as shown in THIS BCM Diagram as G-302:
To make certain, just take a second glance back at Post #143 for the Link to @Realism 's Brilliant Pictorial Collection of where ALL the Ground Locations are situated... ;>)
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Thank for these diagrams. I'm working like a maniac the next two days, but on Friday I'll try to have a look at G107 and the rest.
I hit around this area with a slag hammer (will use an air chisel next) to deal with the rust. The bolt for the ground wire spun right out. With the ground disconnected, I tried to start the engine, and it fired right up. So this isn't the ground for the pump or the relay (almost sure now.)
That's the ground for the EBCM. If you get a Service ABS System warning and a code for loss of communication with the brake module, this is usually the cause of it. Clean up the area with a whiz wheel, install a new bolt and nut and coat the shiny areas with rubber undercoating.
Had a coupon for this cart, so picked it up yesterday. Some assembly required.
Here's the frame after some air chisel work and some light sanding.
Here's the frame after some air chisel work and some light sanding.
Staying busy during project "find the bad ground." Lots of sanding and a light coat of primer.
My Trailblazer has been taking the winter off. It's been sitting in my garage since last fall. I finally got the tank dropped (again) and I'll recheck the pump installation.
Is the Bosch pump supposed to have a filter or is it internal?
Is the Bosch pump supposed to have a filter or is it internal?