1998 5.7 timing question

backyardbum · #1 01-21-2009, 01:19 PM

I am new to this site but I spent all morning reading posts and it looks like a great site.
My problem is on a friend from works truck. It is a 98 1500 with a 5.7 in it. About a month ago I put in a fuel pump. (it wasn't oem but that isn't the problem yet, I read quite a few posts about that) After I finished the fuel pump when I tried to start it it sounded like the timing was off. The truck would turn over a bit and bind like the timing was way off. I check cap and rotor and all the usual things and found nothing wrong. There was a code for cam sensor though which I cleared but the truck still wouldn't start. The owner and his dad had tried to get the truck running and I had no idea what they had done so I checked the distributer and the timing looked right. I could find nothing else wrong and thought maybe they moved the distributer( I couldn't get ahold of the owner) so I started moving the distributer one tooth at a time until the truck started and I ended up right where I started. I played with the timing until the distributer cmp orientation code(I dont remember the name) was cleared and the truck ran great. He drove the truck for a month with no trouble. The truck sat for 3 nights without running and now it sounds like the timing is off again. I havent ever seen a cam sensor intermittently act up, and was hoping someone else had seen this problem and had some ideas for me. I did inspect all the wiring the last time and found no loose connections or bad grounds. Thanks for any help

2000CAYukon · #2 01-21-2009, 02:18 PM

Did you read this thread? http://www.automotiveforums.com/vbul...gnition+timing

It really should be sticky thread.

//2000CAYukon

backyardbum · #3 01-21-2009, 05:09 PM

I read that. I said on my original post the timing sounds like its off, but I didn't say the truck wont even start. every procedure on there says start and run at 1000 rpm.
I stopped and looked at his truck on my way home today but I didn't have my scanner with me to check codes. He bought a new battery today because that was bad, not sure if its related. When you first turn key it turns over pretty fast then stops dead when it tries to fire. Sounds the the timing is advanced about 3 teeth or something. It sounds the exact same as after I changed the fuel pump. I never really figured out why it wouldn't start then. Like I said I kept moving the distributer until it ran then fine tuned it until the correlation code went away, but the distributer ended up right where I started. Today I checked to make sure the distributer was tight and didn't move and it was. The only common thing to both instances is the truck sat for a few days, and after that it wouldn't run. I will check codes tomorrow, I just hoped someone experienced something similar.

Jeremy-WI · #4 01-21-2009, 05:49 PM

It might need a new distributor cap. My 96 has been setting for quite a bit this year because of gas prices. There were times I got lucky and it started and then there were times it would crank and crank and stop cranking and crank again. I put a timing light on, just to check the spark, and noticed the spark wasn't steady, it would seem to fire at random at times. A new distributor cap ad rotor fixed it.

If you put that engine at tdc on cyl #1 and the rotor points at the V shaped pointer with the 8 on it, it should be good enough to start

wafrederick · #5 01-21-2009, 09:51 PM

Vortec 350s and 4.3s are known for eating up distribitor caps,rotors and coils.Seen an Astro van do this,replaced the distribitor cap and rotor which it ran.It quit again days later,bad coil and has not been back after replacing the coil.

2000CAYukon · #6 01-22-2009, 02:22 AM

Also check the dist drive gear for wear.

//2000CAYukon

backyardbum · #7 01-22-2009, 03:55 AM

Thanks, I will try that today after work. The distibuter gear didn't seem to be worn. I'll try the cap and rotor though.

MT-2500 · #8 01-22-2009, 09:48 AM

Timing is not adjustable.
What was the code no.
Set the dist as shown in link.
http://files.automotiveforums.com/ga...hp?photo=51302
http://www.automotiveforums.com/vbul...d.php?t=881442

After truck is started and running get a engine capable scanner and set the camshaft retart as close to -0 or +0 as you can get it.
This is done by turning dist.
And it has to be over a 1K rpm for the new adjustment to readjust on scanner reading.

Also make sure fuel pressure is up to par.

backyardbum · #9 01-22-2009, 04:12 PM

I took my scanner over today after work and there were no codes. The cap and rotor didn't look bad but a few of you said that was probably the problem and I couldn't find anything else wrong so I put in a new one and it started right up. My scanner doesn't show camshaft retard so I wasn't able to check that but there is no correlation code and it is running good so that is best I can do. Thanks for all your help. I will let you all know if it dies again.

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