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Old 12-16-2011, 10:48 PM   #1
BarryB
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Help before I go crazy. 99 suburban 5.7 vortec wont start.

Alright here my story. Bought this 99 suburban with bad motor. The PO said he was driving it when it quit. He had it checked out his mechanic said it had jumped time. I buy it, because I had a 98 5.7 setting in the garage, that had a bent valve. Fixed the valve put it into the burb. get everything back in hooked up. it won't start. I hit the schrader valve on the fuel line. fuel squirts out, so pump is working plus you can hear hit run. It's getting spark pull coil wire spark, pulled a plug and it's firing also. turns over but won't start. Since I had the battery out this whole time and the motor hasn't ran , there aren't any codes. I double checked the distrub. its appears to be right on. I set it with TDC marks on the balancer and timing tab.
So looking for some advice on what to check for. And since I never heard the old motor run, it's making me think it might be something else wrong. I'm using all the stuff from the 98 motor, which I did hear run before pulled. its only problem was the bent valve which I fixed.
Let me know if you need me to explain some more.
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Old 12-17-2011, 12:16 AM   #2
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Check ALL fuses, ecm 1 and ecm first, after that if you have fuel and spark I would pull the upper intake to check the cpsi fuel system and go from there
By the way, we have killed several vortec 5.7 engines here but have never ever bent a valve unless the cam timing was way way off----
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Old 12-17-2011, 12:57 AM   #3
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Quote:
Originally Posted by rickpilgrim View Post
Check ALL fuses, ecm 1 and ecm first, after that if you have fuel and spark I would pull the upper intake to check the cpsi fuel system and go from there
By the way, we have killed several vortec 5.7 engines here but have never ever bent a valve unless the cam timing was way way off----
I"ll double check all the fuses again tomorrow, might have over looked one. The motor that is in the burb now. Was a running motor ran great actually besides the miss from #6. But I fixed all that, even put in a new timing set in. gears and chain. If I'm getting fire, and fuel (at least to the injector). to me my next step would be to see if the injectors are getting the signal from the wiring harness to see if their firing. BUt I am not sure exactly how to check that. can you check with a test light? Lets say, all fuses are good, but no fire from the plug. What would cause that? Bad ECM?
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Old 12-17-2011, 09:23 AM   #4
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Start simple..

check engine compression...

check to make sure your distributor is in time correctly (stabbed correctly)

check for spark

check fuel pressure with a gauge

you need compression, fuel and spark for the engine to run.... one of them is missing....
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Old 12-17-2011, 11:18 AM   #5
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

I back up what tommie said about cking fuel pressure with a gauge.I had one that was only a couple pounds off, and it would not start. Seemed to have plenty at schrader valve without gauge, but after hooking up gauge was low just a bit and would not start!
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Old 12-17-2011, 11:46 AM   #6
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Ok, I need to go buy myself a guage then. has spark, has compression. I put the dis. in correctly.
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Old 12-17-2011, 04:47 PM   #7
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

do you have a check engine lite on ,with key on engine off?

also check both ground wires from back of motor to firewall..for good clean contact...It may be something simple...

try turning the dist...a little and see if it will hit..They have to be set right on (0) or will not run...I had the same problem not to long ago...
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Old 12-17-2011, 06:25 PM   #8
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Well after, alot more tinkering. Still wont start. Moved the dis around. nothing, has 60psi fuel pressure. checked all the fuses there good.
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Old 12-17-2011, 08:15 PM   #9
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

do you have the air cleaner and air flow meter hooked up on it?

just thinking of what it could be..
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Old 12-17-2011, 10:07 PM   #10
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

I would double check the distributor again, you probably already know that it can be installed 180 degrees out as the timing marks on the balancer will line up on the compression and exhaust stroke, you should be on the compression. Also, when the balancer marks are lined up on the compression stroke, you stab the dist and line up the rotor with the small triangle (should have a 8 stamped in it) in the base of the dist. Here is a post with picks: http://www.67-72chevytrucks.com/vboa...ighlight=P1345 Also note that your timing is not adjustable on these engines. Moving the distributor around changes the cam timing. Even with the cam timing off a tooth or so the engine will still start, it just may run poorly and set the engine light with a P1345.

If the dist is good, you can check the plugs to see if they have fuel on them to see if you are getting the injectors to fire. You could also use a small spray of starting fluid to see if it starts. If so, your issue would be more than likely fuel related.
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Old 12-17-2011, 11:39 PM   #11
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

You swapped engines before troubleshooting? Wow.
You might want to see if you have spark at the plug.
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Old 12-18-2011, 09:52 AM   #12
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

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Originally Posted by 70BLAZERX2 View Post
do you have the air cleaner and air flow meter hooked up on it?

just thinking of what it could be..
Yes I have it hooked up somewhat, Its plugged in, and such but not buttoned down completely, it still should at least tried to hit.

Quote:
Originally Posted by bwood View Post
I would double check the distributor again, you probably already know that it can be installed 180 degrees out as the timing marks on the balancer will line up on the compression and exhaust stroke, you should be on the compression. Also, when the balancer marks are lined up on the compression stroke, you stab the dist and line up the rotor with the small triangle (should have a 8 stamped in it) in the base of the dist. Here is a post with picks: http://www.67-72chevytrucks.com/vboa...ighlight=P1345 Also note that your timing is not adjustable on these engines. Moving the distributor around changes the cam timing. Even with the cam timing off a tooth or so the engine will still start, it just may run poorly and set the engine light with a P1345.

If the dist is good, you can check the plugs to see if they have fuel on them to see if you are getting the injectors to fire. You could also use a small spray of starting fluid to see if it starts. If so, your issue would be more than likely fuel related.
I've had the dist. out numerous times resetting it all with the tiiming tab. I'll double check it again. The dist. was recently installed. It doesn't have a 1000 miles on it. I'm getting spark to the plugs. I had #1 out and grounded it was sparking. I pulled out #2 there was some fuel on the plug. Didn't look like enough to foul it out though. I haven't squirted any ether down it yet.

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You swapped engines before troubleshooting? Wow.
You might want to see if you have spark at the plug.
Yeah Hind sight, I know. It wouldn't start before I did try a couple of things, but didn't do to much since the PO told me his mecahnic said it had jumped time. the motor had 250k on it so I didn't give it much thought. I decided to pull the timing cover last night on the old motor, It lined right up dot to dot. So his mechanic was wrong.
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Old 12-18-2011, 11:19 AM   #13
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

If and it's a big if. You have fuel, spark and compression. Than the spark is happening at the wrong time. Simple as that.

So the question is how do you know you have compression? Cause you heard it run when you yanked out the donor vehicle?

Incidentally a SBC will not run if it looses spark to 3 or more plugs. Did you check all 8?
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Old 12-18-2011, 09:53 PM   #14
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

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If and it's a big if. You have fuel, spark and compression. Than the spark is happening at the wrong time. Simple as that.

So the question is how do you know you have compression? Cause you heard it run when you yanked out the donor vehicle?

Incidentally a SBC will not run if it looses spark to 3 or more plugs. Did you check all 8?
This motor did run when I pulled it out. No, I did not check all 8.
The former owner of this Burb, had the dist. replaced,because the mechanic said it was bad. So new dis. and etc. Burb was running again. He was driving down the road, when it died. He had another "ASE CERTIFIED GM " mechanic look at it. He said the original motor had jumped time. Well last night just cuz. I pulled the old motor apart to see. The dots lined up perfectly. Chain had a lil slop, but nothing unexpected. SO this leads me to believe that what ever caused the original motor to quit is still the problem.
NOW, I did pull the injector plug, all I had was a circuit tester, I put it to the hot side of the injector leads. had someone crank it over. It would light up and stay lit. It didn't pulsate. It did this on all the ones I tried. soon as you started cranking it would light up and stay lit. Is that right????
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Old 12-18-2011, 11:23 PM   #15
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Once you know you have compression, you have verified spark at #1 tdc, everything is hooked up correctly and all fuses and relays are good try pouring some fuel in the throttle body, putting the hat back on and try it. A guy brought us a 97 S10 w/4.3 vortec, 82K miles, left in the shed for 4 yrs while in the army, came home put in new battery and no start. Came to us, scanner(We have a Snap On Modus bi directional w/lab scope, very expensive) said everything ok so a cup of fuel and it started right up and is running great again. Boneyard guys swear that all these FI motors sit a few yrs maybe 2 in 20 start, the rest need a bit of fuel to go. It should at least pop or fire with this if the problem is fuel related. If it starts and quits----
I don't know if the posative side or the negative side pulses. What I would do next is pull the upper intake off, plug all fuel lines and wiring back into the spider, pull the nozzles out of the lower intake and let them lay on the lower, unhook the coil wire, put on the eye protection and observe the system as someone cranks it over. You should have a nice cone shaped spray out of each nozzle. If none work it's either all the nozzles are plugged(not likely) the spider assembly needs replacement due to a dead electrical side(possible, our S10 did this) or there is a problem in the PCM system.
If it does have a nice spray on all 8 the problem is not there. I wish I could plug the scanner in and watch the data while cranking. Then I would know.
By the way, we have 2 1998 5.7 Vortecs, a 1996 4.3 Vortec and a 1997 7.4 Vortec and ALL will start/run without the MAF/Air cleaner hooked to the throttle body.

Last edited by rickpilgrim; 12-18-2011 at 11:42 PM.
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Old 12-19-2011, 07:53 AM   #16
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Quote:
Originally Posted by rickpilgrim View Post
Once you know you have compression, you have verified spark at #1 tdc, everything is hooked up correctly and all fuses and relays are good try pouring some fuel in the throttle body, putting the hat back on and try it. A guy brought us a 97 S10 w/4.3 vortec, 82K miles, left in the shed for 4 yrs while in the army, came home put in new battery and no start. Came to us, scanner(We have a Snap On Modus bi directional w/lab scope, very expensive) said everything ok so a cup of fuel and it started right up and is running great again. Boneyard guys swear that all these FI motors sit a few yrs maybe 2 in 20 start, the rest need a bit of fuel to go. It should at least pop or fire with this if the problem is fuel related. If it starts and quits----
I don't know if the posative side or the negative side pulses. What I would do next is pull the upper intake off, plug all fuel lines and wiring back into the spider, pull the nozzles out of the lower intake and let them lay on the lower, unhook the coil wire, put on the eye protection and observe the system as someone cranks it over. You should have a nice cone shaped spray out of each nozzle. If none work it's either all the nozzles are plugged(not likely) the spider assembly needs replacement due to a dead electrical side(possible, our S10 did this) or there is a problem in the PCM system.
If it does have a nice spray on all 8 the problem is not there. I wish I could plug the scanner in and watch the data while cranking. Then I would know.
By the way, we have 2 1998 5.7 Vortecs, a 1996 4.3 Vortec and a 1997 7.4 Vortec and ALL will start/run without the MAF/Air cleaner hooked to the throttle body.
This motor didn't sit for too awful long. Are you wanting me to pull the injector to see if it's getting signal to the injectors? or to see it the injector has gone bad?

I have a friend that has a scanner, just the problem is getting up with him. I'll try to see about getting it to him.
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Old 12-19-2011, 09:02 AM   #17
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

I would first dump a cup of fuel down the throttle body and try to fire it up. That will either make it start and quit, make it start and run, or do absolutely nothing. Doing that will tell you if your problem is or isn't fuel related, nothiing more or less. Please keep in mind here I'm talking about a shot glass sized cup here, nothing more that would flood the motor.
Now if it starts and quits then you have to look futher. That cspi system is a sealed assembly, meaning you can unplug the fuel lines, unhook the main wiring harness, replace the fuel pressure regulator and that's it. There are no individual injectors per say, it is a spider assembly that has fuel lines that plug into the intake and the main wiring hookup and fuel line hookups and beyond the regulator is non serviceable.
So if you dont have the GM service plug to hook up a diagnostic meter to that main plug the next best way I know to test it is to pull off the upper (plastic) intake, pull the little hoses out of the lower(aluminum) intake and leave them out where you can see them. Hook the main fuel lines up, the wiring back up,unplug the coil wire from the distributor so it doesn't start and crank it over to see if it is spraying fuel out of the 8 little lines. If nothing then you have to replace that cspi spider assembly with a known good unit and repeat the test to see if it sprays fuel.
If you still have no fuel spray the problem is in the wiring or pcm and the way we find that is to hook up our Modus and test the system from the diagnostic port first and if thats good it's a wire by wire test from the PCM to the system and very time consuming, not to mention very unlikely unless the wiring got damaged in the engine swap. Do keep in mind here this is a 5 volt system on the computer system, DO NOT apply 12 volts to any part of the PCM system as that ruins parts fast.

Last edited by rickpilgrim; 12-19-2011 at 09:10 AM.
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Old 12-19-2011, 06:37 PM   #18
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Quote:
Originally Posted by rickpilgrim View Post
That cspi system is a sealed assembly, meaning you can unplug the fuel lines, unhook the main wiring harness, replace the fuel pressure regulator and that's it. There are no individual injectors per say, it is a spider assembly that has fuel lines that plug into the intake and the main wiring hookup and fuel line hookups and beyond the regulator is non serviceable.
So if you dont have the GM service plug to hook up a diagnostic meter to that main plug the next best way I know to test it is to pull off the upper (plastic) intake, pull the little hoses out of the lower(aluminum) intake and leave them out where you can see them. Hook the main fuel lines up, the wiring back up,unplug the coil wire from the distributor so it doesn't start and crank it over to see if it is spraying fuel out of the 8 little lines. If nothing then you have to replace that cspi spider assembly with a known good unit and repeat the test to see if it sprays fuel.
If you still have no fuel spray the problem is in the wiring or pcm and the way we find that is to hook up our Modus and test the system from the diagnostic port first and if thats good it's a wire by wire test from the PCM to the system and very time consuming, not to mention very unlikely unless the wiring got damaged in the engine swap. Do keep in mind here this is a 5 volt system on the computer system, DO NOT apply 12 volts to any part of the PCM system as that ruins parts fast.
Whoa wait a minute here. I'm not trying to pick on you directly, but alot of what I want to address is in your post thats why I pulled it. Theres alot of things that have been mention in above posts, and in this one that are things to check, but you are getting way more difficult than needs be.

First of the injectors. I have seen this style of injector, actually end up with all 8 stuck after sitting just 7 months. And it used to be that you could get individual injectors thru gm and only replace the ones that are stuck, however you are much better off upgrading to the multec style kit that is available to eliminate these issues all together. Now as far as checking for stuck injectors, pulling the plenum and injectors all out to find out if they are working is very much time consuming and not necessary. Now rickpilgrim, if you have a Modis or to any of you if you have a bidirectional scan tool available to you. hook it up with the fuel pressure gauge hooked up to the test port. Go into the injector drop test. (for modis or snap-on users this is in the functional test menu.) Watch the fuel pressure for a drop when each injector is fired. If it drops it's good if it doesn't it's stuck. this is a quick maybe 5 min test that will tell you not only if any are stuck but which ones. This can also be used as a preliminary test as to if the wiring is good. Even if the injectors are stuck they will still make a faint ticking noise. If they either work or don't it will indicate if the wiring is ok. Now obviously if there is no noise whatsoever then you need to be looking elsewhwere for ther problem as has also been stated. I guess my point is you can check a bunch of things in just a few minutes, without taking anything apart. Don't make things harder than they need to be or possibly create more issues that might arise by taking stuff apart that doesn't need to.

However I haven't seen one shut off while running because of injectors just all of a sudden plugging up, so you still may have issues elsewhere.
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Old 12-19-2011, 10:05 PM   #19
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

bighaas79- I also don't have a problem with you, here's why I said what I did.
I realize you can use the Modus to do the pressure drop test, and you can set it lab scope mode and check the signal going to the assembly. That being said, our 98 K2500 was running extreemly rough when we got it, we did exactly what you said and it checked out perfect, just running a bit rich. Ended up pulling up the upper intake and found a few leaking lines and a little puddle of fuel in the intake, yet the data in the Modus said all ok and we followed the test instuctions that are in the modus.
Now I was thinking not everyone has this $6259.43 piece of equipment laying around, most have only a code reader with maybe a data display at best, like our ez5000 or ez6000. Thats why I posted that, as I don't know any other "low tech" way to do it.
Also, disconnect the battery for a week or two and the trouble codes go away and I have never seen the pcm set any trouble codes beyond the CPS if the engine won't run. Code reader no help here either
Like I said, try a cup of fuel down the intake first, that will at least point you in the right direction of where to look.
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Old 12-19-2011, 10:05 PM   #20
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

I've had to walk away from this project. I have other projects needing done paying jobs that is. so I'll get back to it again here soon. I plan on double checking all eight cylinders for compression and spark when I get back to it. Like I mentioned I probably have my friend take a look at it. he has a scanner.
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Old 12-20-2011, 05:43 AM   #21
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Ground is pulsed, not +12

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I put it to the hot side of the injector leads. had someone crank it over. It would light up and stay lit. It didn't pulsate. It did this on all the ones I tried. soon as you started cranking it would light up and stay lit. Is that right????
Injectors always have +12 volts when the key is on. The PCM pulses the ground to fire them. Incidentally, it happens so fast you need a noid light to see it.
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Old 12-20-2011, 08:22 PM   #22
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

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bighaas79- I also don't have a problem with you, here's why I said what I did.
I realize you can use the Modus to do the pressure drop test, and you can set it lab scope mode and check the signal going to the assembly. That being said, our 98 K2500 was running extreemly rough when we got it, we did exactly what you said and it checked out perfect, just running a bit rich. Ended up pulling up the upper intake and found a few leaking lines and a little puddle of fuel in the intake, yet the data in the Modus said all ok and we followed the test instuctions that are in the modus.
Now I was thinking not everyone has this $6259.43 piece of equipment laying around, most have only a code reader with maybe a data display at best, like our ez5000 or ez6000. Thats why I posted that, as I don't know any other "low tech" way to do it.
Also, disconnect the battery for a week or two and the trouble codes go away and I have never seen the pcm set any trouble codes beyond the CPS if the engine won't run. Code reader no help here either
Like I said, try a cup of fuel down the intake first, that will at least point you in the right direction of where to look.
Ya I realize that not everyone does have access to scanners, but after him saying his friend had one I just figured the scanner route would be a much faster method. As far as low tech way to do it, you bet, pullin the upper plenum is probably the only way to go. It's just a little more time consuming.
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Old 12-21-2011, 05:46 AM   #23
speedygonzales
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

The only "low cost" way to detect where the fuel system is loosing pressure is to put a shut off valve in the fuel supply line to the engine. After shutting the engine down, immediately close the valve to eliminate the fuel pump check valve as the culprit.

If the pressure goes down even after closing the valve, you only have 2 choices. Both of which are under the upper plenum on a L31.
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Old 01-05-2012, 11:13 AM   #24
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

Well I gave the PO a call, left him a message for him to call me. I'm hoping he might be able to explain to me again what this Burb was doing when it quit. I haven't gotten it put on a scanner as of yet. Been busy doing other projects. But my newborn twins are 6 weeks old today. So my wife is going to be getting anxious to get out of the house with them. taking them and my 3 year old out in our Honda accord is a little cramped to say the least. hence the need of the burb with the third row seat.
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Old 01-05-2012, 08:03 PM   #25
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Re: Help before I go crazy. 99 suburban 5.7 vortec wont start.

He called me back, He told me he was driving down the interstate. Realized he didn't have any power looked down all the guages were zeroed. That was it, it was dead. Sp according to him it just shut off, and hadn't started since. Apparently it had to have been acting up some because he had just had the the dist, replaced, with a full tune-up.

On another note, I have been looking into gettting myself a scanner, but wouldn't know how to use it. I'm thinking my friend that has the scanner might have an older one. I'm pretty sure it's a snap on, but don't know the model number. If it is already sold, do you guys any suggestions for one. I won't have a need for a top of the line one seeing I'd only use it on occasion.
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*We could learn a lot from crayons... Some are sharp; some are pretty;and some are dull. Some have weird names; and all are different colours;but they all have to live in the same box.

* You may be only one person in the world, But you may also be the world to one person.

* Some mistakes are too much fun to only make once.

Two rules in life.
1. Never sweat the small stuff!
2. Everything is small stuff!

Last edited by BarryB; 01-05-2012 at 08:09 PM.
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