cschreyer

Hey guys new here, just picked up a 97 2500 with the 5.7 vortec motor. It was misfiring pretty bad when i bought it and throwin a few codes, so I did some research and figured out it was a worn distributor gear. so i pulled the distributor and sure enough it was worn down pretty bad, got a new distributor but it took a week for it to ship in and by the time the new one came in I forgot where the old one was lined up for timing.

I've read a lot of different posts telling how to place the distributor but im still having some problems so maybe someone can help clear things up for me a little bit. heres what i did

set the number one cylinder to top dead center on the compression stroke.
placed the distributor with the rotor facing the number one cylinder.
started the truck but its still misfiring and its throwing the p1345 code which apparently has to do with timing.
i have an elmscan5 compact scan tool running obdwiz and it shows what timing is currently set at and its telling me that im at 29 degrees. if i understand right it should be reading 0 so i figured my distributor was off by a gear, so i rotated one tooth clockwise and it started up but it ran like crap and the timing now read 33ish degrees. so i went back 2 teeth the opposite way and it wouldn't start up at all...

anyway i put it right back where it was before and its still reading 29 degrees and misfiring (although not nearly as bad as it did before i changed the distributor) so im not sure what to do from here.

sorry for such a long post and for having to ask questions on my first post haha its probably just something stupid. Im used to old cars, before this i had an old 63 corvair and you could just turn the dist to adjust timing (way easier haha)
thanks
caleb

cschreyer

Just found out that the timing advance my program shows may not be the cam timing but ignition timing. Got another program ill try out in the morning and see if that works...

shamrock246

Your looking for a scanner that reads Cam Retard should be set to 0 +/-2 a tech 2,snap-on,Auto xray 6000 will read it.A dealer ship might not charge you much to set it just make sure you rev the engine past a 1000 rpm to reset the value on the scanner

Autoxray EX Scan 6000 | eBay

cschreyer

have a friend with the scan xl pro software and the gm dealer addon pack. It shows cam to crank correlation and it looks like im actually within the 2 degrees. Problem is im still showing the p1345 code, since i got a new distributor with the new cam sensor on it im thinking it may be the Crank position sensor. Ill probably go pick one up and try it out but before i waste $60 anyone have any other thoughts or ideas?

edit* stupid me, setup the program wrong. got the program to scan and i was way out. adjusted the distributor and now im at 3* problem is it only ran like that for about a minute and then it started backfiring and died... hmmm

cschreyer

Got the timing finally set, had to wobble out the hold down plate hole and adjust the distributor by hand but I'm now at exactly -1*. New problem though its misfiring pretty bad. Have new distributor, cap, rotor, plugs, and wires. Compression is good on all cylinders and its no longer throwing a 1345 code anyone have any ideas?

shamrock246

Whats the fuel pressure?it could be a dieing spyder injector assy amazon,parts geek and rock auto have good prices on the upgraded unit,if you do get one get a DELPHI or AC/DELCO unit

cschreyer

Thanks for the response! I thought for sure it was the intake manifold gasket today (was slowly losing a bit of water) so I went ahead and replaced it, the old one was really nasty and there was practically nothing left next to the water ports towards the front of the motor. Got it all back together and it is defiantly running a lot better but it's still misfiring. I didn't even think to check fuel pressure I figured if it ran as well as it did its probably alright but ill give it a shot tomorrow morning. I'm still not convinced my cap and rotor are good, the new distributor came with a new set but they seem kinda cheep, ill pick up a new one tomorrow. Sure hoping its not a head gasket, but I have over 140 compression on every cylinder so I don't think it is.

cschreyer

Well fuel,preassure on the rail is sitting at 60lbs, could it still,be the spider assembly? I'm kinda thinking that's all that's left that it can be. Amazon has a delphi scpi to mfi on version kit for 263, don't think that's a bad price, might give it a shot

shamrock246

Thats the one but before you jump on that how old is the cap,rotor,wires and plugs?if you have no history on it i would try that first there sensitive to poor ignition parts if your going to replace them get the AC/DELCO stuff

Are there any codes?

Did any coolant get in your oil?

cschreyer

Sorry I didn't get back to you earlier I replaced the cap rotor and wires at the start thinking that's all it was. No coolant in the oil I went ahead and did the spider assembly today and thats exactly what was wrong. Running great now! I really appreciate the input, and I'm glad it worked now I need to start on some rust repair for those toolboxes. Thanks again oh and no more codes yet, but ill get a few miles on it and see what happens