Another "wont start" thread (sorry)
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Another "wont start" thread (sorry) OK guys, Ive tried searching, and done lots of reading on this site for a year or so now, so please try to give me a hand.
Im having trouble getting my project to start.
Its a 2001 4.8L 4L60E into a 87 Olds 442. Factory truck harness was mod'd by Speartech. Im using the Olds starter wiring to the starter. When I hook up HP Tuners to it and open the gauges screen I can see all the inputs are coming in fine...throttle moves, MAF, MAP, ECT all show 'correct' values. When I roll the engine the tach shows around 140 RPM or so. I dont have the drivers side o2 sensor screwed in yet (exhaust isnt done yet), but I hooked it up.
Im pretty sure that Ive disabled VATS properly (I think it should start then die anyways if I didnt), and when I check the DTCs there isnt anything there about antitheft. I have checked my connections and grounds, Im sure that my harness has 3 grounds, 2 at the back of engine by the oil pressure sender, and one up by the alternator. Now that I think of it, I sorta wonder if that one by the alternator is NOT a ground and actually connects to the alternator. Is that true??
If anyone has any knowledge or tips they could throw my way, I greatly appreciate it. Thanks guys.
Im having trouble getting my project to start.
Its a 2001 4.8L 4L60E into a 87 Olds 442. Factory truck harness was mod'd by Speartech. Im using the Olds starter wiring to the starter. When I hook up HP Tuners to it and open the gauges screen I can see all the inputs are coming in fine...throttle moves, MAF, MAP, ECT all show 'correct' values. When I roll the engine the tach shows around 140 RPM or so. I dont have the drivers side o2 sensor screwed in yet (exhaust isnt done yet), but I hooked it up.
Im pretty sure that Ive disabled VATS properly (I think it should start then die anyways if I didnt), and when I check the DTCs there isnt anything there about antitheft. I have checked my connections and grounds, Im sure that my harness has 3 grounds, 2 at the back of engine by the oil pressure sender, and one up by the alternator. Now that I think of it, I sorta wonder if that one by the alternator is NOT a ground and actually connects to the alternator. Is that true??
If anyone has any knowledge or tips they could throw my way, I greatly appreciate it. Thanks guys.
What color is this wire? The only wire that could be hooked up like a ground is the red power wire to the alternator. If you did that, it would arc like hell when you hooked up the battery. Not sure if that would stop it from starting or not, unless you blew a fuse or something. Are you getting power to the coils and injectors? Do you have fuel pressure?
Unless the 4.8 harness is different from an LS1, there should be three grounds at the back of the head. Since it's a newer harness, there may be only two, but all the LS1's had three.
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Thanks for the help guys.
That wire is black, thats why I grounded it initially. And Im pretty sure there was only the 2 wires at the back, Ill look at the GM sketches and see.
My Speartech harness came with a new fuse block in it, its 4 fuses, none of which have blown.
When I turn the key to RUN, the fuel pump comes on and primes fine, I hooked up HP Tuners to it, and forced the pump on for a couple minutes too, it works fine, its a Walbro 255. I dont have a fuel pressure gauge, but when I popped the test port schrader, fuel spurted out of there.
Also, I forgot to mention that while in VCM Scanner, I can see that the PCM is throwing 12* of timing and the injectors are cycling, I think it was like 12 to 8 depending how long I cranked I think. And when I go under the car, I can smell fuel, so I think its acutally getting fuel.
And also, it 'sounds' like it wants to fire, like it rolls and then the RPM picks up a bit then rolls then the RPM picks up again, you guys know that sound.
Part of me thinks its flooded, I dont know at this point.
That wire is black, thats why I grounded it initially. And Im pretty sure there was only the 2 wires at the back, Ill look at the GM sketches and see.
My Speartech harness came with a new fuse block in it, its 4 fuses, none of which have blown.
When I turn the key to RUN, the fuel pump comes on and primes fine, I hooked up HP Tuners to it, and forced the pump on for a couple minutes too, it works fine, its a Walbro 255. I dont have a fuel pressure gauge, but when I popped the test port schrader, fuel spurted out of there.
Also, I forgot to mention that while in VCM Scanner, I can see that the PCM is throwing 12* of timing and the injectors are cycling, I think it was like 12 to 8 depending how long I cranked I think. And when I go under the car, I can smell fuel, so I think its acutally getting fuel.
And also, it 'sounds' like it wants to fire, like it rolls and then the RPM picks up a bit then rolls then the RPM picks up again, you guys know that sound.
Part of me thinks its flooded, I dont know at this point.
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Would an old school timing light clamped around one of the plug wires still light up and show the voltage?? I think it would, unless there is something that prevents that from working. Do the coil packs themselves have to be grounded, or does the wiring take care of that?? Are the coil pack assemblies side specific??
My battery is kinda low, but I had the charger on it, and set it to ENGINE CRANK while I was trying to start it.
Gonna have to get the comb out I guess.
My battery is kinda low, but I had the charger on it, and set it to ENGINE CRANK while I was trying to start it.
Gonna have to get the comb out I guess.
starting Shoot a little gas in the tb and crank it over, does it start? has it ever started since the harness swap? should be able to measure voltage at the inj with a dvm? Is it a DBW or cable throttle?
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Im at work right now, so I cant play with it right now. Ill try a squirt of fuel in the TB. Its a cable TB. This thing has not ran since the harness swap and hasnt ran in probly a year and half total time. Its the factory harness, just mod'd by Speartech.
I have a ground strap from the spot by the oil pressure sender going to the firewall, the battery is grounded to the cylinder head and also to the body, and there is also a ground strap I added from the A/C compresser mounting bolt to the frame. The engine is also solid mounted with Moroso mounts and Transdapt adapter plates. Lots of metal to metal contact.
I have a ground strap from the spot by the oil pressure sender going to the firewall, the battery is grounded to the cylinder head and also to the body, and there is also a ground strap I added from the A/C compresser mounting bolt to the frame. The engine is also solid mounted with Moroso mounts and Transdapt adapter plates. Lots of metal to metal contact.
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Thanks for the help guys.
I looked at some stuff last night when I got home from work. Im very sure there are only 2 grounds that attach at the oil sender spot and 1 thats gets bolted up front, I put it to the head, but the GM drawings show it going to the block and touching the negative connection from the battery. Ive got it touching the negative too, just on the head.
Would the O2 sensors not being bolted in cause any of this?? My exhaust isnt done and I dont have anywhere for the drivers side to screw into.
Ill try a squirt of fuel in the intake, Id also like to hook up a fuel pressure guage to make sure Ive got the pressure.
I looked at some stuff last night when I got home from work. Im very sure there are only 2 grounds that attach at the oil sender spot and 1 thats gets bolted up front, I put it to the head, but the GM drawings show it going to the block and touching the negative connection from the battery. Ive got it touching the negative too, just on the head.
Would the O2 sensors not being bolted in cause any of this?? My exhaust isnt done and I dont have anywhere for the drivers side to screw into.
Ill try a squirt of fuel in the intake, Id also like to hook up a fuel pressure guage to make sure Ive got the pressure.
You should also have a ground strap from the block to the frame. If the block isn't properly grounded this could give you the no start condition.
If vats isn't turned off it will not start either. You said you think you had it turned off, you may want to check again.
Do you atleast have headers or manifolds on the motor?
If vats isn't turned off it will not start either. You said you think you had it turned off, you may want to check again.
Do you atleast have headers or manifolds on the motor?
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You should also have a ground strap from the block to the frame. If the block isn't properly grounded this could give you the no start condition.
If vats isn't turned off it will not start either. You said you think you had it turned off, you may want to check again.
Do you atleast have headers or manifolds on the motor?
If vats isn't turned off it will not start either. You said you think you had it turned off, you may want to check again.
Do you atleast have headers or manifolds on the motor?
And the motor is solid mounted as well.
I have LS1 Camaro manifolds on it, the truck ones dont clear.
In HP Tuners I set the VATS to 'none' in one tune and to 'pwm' in another, neither of them made a difference. Right now I have the 'pwm' tune in it, with code 1626 turned off. Also, as Ive said before, I havent gotten a DTC talking about antitheft at all.
Tonite Im gonna clean and scrape where all the grounds go and the battery connectors too, squirt some fuel in it, and see what happens.
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Dont forget to make sure your PCM is properly grounded as well, even though you can communicate with it give it a check anyways. Ive heard about battery voltage being an issue too. when you have your charger on it, check if its up there. Also, if you are not using the starter circuit through the pcm, but the chassis, check to make sure its not something simple like a clutch switch input.
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Dont forget to make sure your PCM is properly grounded as well, even though you can communicate with it give it a check anyways. Ive heard about battery voltage being an issue too. when you have your charger on it, check if its up there. Also, if you are not using the starter circuit through the pcm, but the chassis, check to make sure its not something simple like a clutch switch input.
Dont ground the ECM itself, Im sure he meant the ECM grounds that come via the wiring harness, which should be heading to one of those ring terminals on the head anyhow. You need the VATS set to none just to clear that up. PWM won't work. Obviously that isnt your problem since you said you tried anyway, but make sure you use the tune with it set to none. Have you tried spraying any starting fluid yet to see if it coughs to life at all? Both temp sensors hooked up and reading right in the scanner? If both IAT and the engine temp sensor are unhooked or nonfunctional it wont start...kinda a long shot Im just trying to cover the bases.
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I think I got the grounds you are talking about grounded properly. 2 at the back, one at the front.
Thanks for clearing up the VATS thing for me, Ill set it up as it should be.
Its a truck harness, so the IAT is integrated with the MAF, and its hooked up and reading good. The ECT is hooked up and reading good too. The IAT and ECT were reading like 2 degrees from each other.
Ill clean up the grounds, throw the charger on it, change the VATS stuff, and hit it with some starter fluid and see what happens.
Thanks for clearing up the VATS thing for me, Ill set it up as it should be.
Its a truck harness, so the IAT is integrated with the MAF, and its hooked up and reading good. The ECT is hooked up and reading good too. The IAT and ECT were reading like 2 degrees from each other.
Ill clean up the grounds, throw the charger on it, change the VATS stuff, and hit it with some starter fluid and see what happens.
I think I got the grounds you are talking about grounded properly. 2 at the back, one at the front.
Thanks for clearing up the VATS thing for me, Ill set it up as it should be.
Its a truck harness, so the IAT is integrated with the MAF, and its hooked up and reading good. The ECT is hooked up and reading good too. The IAT and ECT were reading like 2 degrees from each other.
Ill clean up the grounds, throw the charger on it, change the VATS stuff, and hit it with some starter fluid and see what happens.
Thanks for clearing up the VATS thing for me, Ill set it up as it should be.
Its a truck harness, so the IAT is integrated with the MAF, and its hooked up and reading good. The ECT is hooked up and reading good too. The IAT and ECT were reading like 2 degrees from each other.
Ill clean up the grounds, throw the charger on it, change the VATS stuff, and hit it with some starter fluid and see what happens.
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Got it runnin, sorta K, so I looked for more PCM grounds, couldnt find any.
Removed all my ground straps, battery connection and wire brushed them and reinstalled.
Hooked up batter charger.
Updated my tune to correct the VATS.
Turn the key.....just rolls and doesnt fire....just like it was doing before.
Go get the can of starter fluid, spray some in the TB.
Turn the....rolls and SPITS AND FIRES AND DIES. Woohoo, Im thinkin.
More starter fluid this time.
More rumbling to life and dying.
Repeated a few times, and eventually got around 800 RPM out of it and a register on the MAP and MAF sensors.
Needless to say, Im pretty happy about this.
So this obviously solves a few issues, and pretty much just leaves FUEL as my problem. Could be low pressure somehow, plugged injectors, or both.
My fuel system goes like this:
Stock 87 Olds 442 fuel tank.
Stock sender with the VAPOUR line being used as the return line, it had a sort of deflector in the way, I removed it and found an oriface in the stub of the tube, so I drilled it out.
Walbro GSL 392 pump.
Fuel filter for a 98 Chev 1/2 ton truck.
All piping from tank to rail is 3/8".
Rail is stock 2001 4.8 with a return line.
Russell brand adapters on rail to adapt AN to the GM push on fittings.
Return line immediately after adapter fitting is 3/8" for about 12" then a reducing coupling to 5/16".
5/16" return to tank.
I do NOT have a fuel pressure gauge. Is it true that the test port fitting is just a 1/4" NPT with a schrader valve in it?? Does the schrader unscrew just like a tire valve??
Does anyone have any ideas or advice they can throw my way??
Ive attached my tune and log for those with HPT if the wanna have a look.
Removed all my ground straps, battery connection and wire brushed them and reinstalled.
Hooked up batter charger.
Updated my tune to correct the VATS.
Turn the key.....just rolls and doesnt fire....just like it was doing before.
Go get the can of starter fluid, spray some in the TB.
Turn the....rolls and SPITS AND FIRES AND DIES. Woohoo, Im thinkin.
More starter fluid this time.
More rumbling to life and dying.
Repeated a few times, and eventually got around 800 RPM out of it and a register on the MAP and MAF sensors.
Needless to say, Im pretty happy about this.
So this obviously solves a few issues, and pretty much just leaves FUEL as my problem. Could be low pressure somehow, plugged injectors, or both.
My fuel system goes like this:
Stock 87 Olds 442 fuel tank.
Stock sender with the VAPOUR line being used as the return line, it had a sort of deflector in the way, I removed it and found an oriface in the stub of the tube, so I drilled it out.
Walbro GSL 392 pump.
Fuel filter for a 98 Chev 1/2 ton truck.
All piping from tank to rail is 3/8".
Rail is stock 2001 4.8 with a return line.
Russell brand adapters on rail to adapt AN to the GM push on fittings.
Return line immediately after adapter fitting is 3/8" for about 12" then a reducing coupling to 5/16".
5/16" return to tank.
I do NOT have a fuel pressure gauge. Is it true that the test port fitting is just a 1/4" NPT with a schrader valve in it?? Does the schrader unscrew just like a tire valve??
Does anyone have any ideas or advice they can throw my way??
Ive attached my tune and log for those with HPT if the wanna have a look.