[jimmyjimny]

Hey guys, I just put my sierra back together after doing the head only to find the thing barely blood starts now. It just wouldn't kick over until I gave the pedal some stab and that got it going, but it died seconds later. So I crank it again and it fired up everytime but still died out,after a few more tries with it still dying I decided to keep the revs up for a while and this smoothed it out a bit so after 30 or so seconds I took my foot off and it held idle. Happy it was running by itself I let it idle for a few min and a lot of the missing disappeared and it was running almost normal but still rough, and a bit chuggy.

Well that was yesterday and I've gone to start it today and have had the exact same issue.. wouldn't even kick over and had to do the same crap as yesterday to get it to hold idle again. Being an exact repeat of yesterday. I just tried starting it again before (after a few hours of sitting) and it struggled to start up, but it did hold idle. I'm betting if I leave it overnight and try tomorrow it's going to be a lot harder to start and won't hold idle. The longer it sits the harder it starts is what I think is happening here. It was running fine before I took the head off it so I wouldn't think it's carb related. Would anyone know what could be making it do this? Sorry it's probably something simple, I've never owned a car with a carby before but this is what seems to be happening

-Cold motor won't start up unless I give it some throttle (still takes minutes of cranking to even get a kick).
-Once it's going it's going but dies out after a few seconds of idling unless I hold the revs up
-after the revs it runs and doesn't stall and smooths out after a few mins idling
-come back the next day expecting a nice smooth idle and cleared out carb only to repeat the process!

I've been on this for almost 3 days haha it's so bad and there's an oil leak coming from near the dipstick somewhere too and anytime I try to get anywhere near it the fanbelt catapults oil into my face! Now the heads on I really cbf with all these little things I think i'd rather pull the head again

[Rhinoman]

Have you done a compression test? you may have the valve timing wrong.

[303zuke]

Is the Auto Choke re-connected and working?

[JrZook]

303zuke wrote:

Is the Auto Choke re-connected and working?

+ all vacuum hoses

[Dec]

I'm currently having the same issue with her starting and not holding revs and stalling. I called my mechanic and he's told me to check all vac lines and check the pcv valve as it may be blocked.

[jimmyjimny]

hmm thanks guys the auto chokes working and the vacuum lines are all good! (well I broke the EGR sensor up the front so I just bypassed it) It's strange. I still need to do a compression test but checked the timing mark on the cam/all sprockets and it's in line so the valve timing would be fine unless the valves have bent?? I was in the process of doing the compression test and got distracted by all these metal shavings that seem to be coming off some washer ring behind the crank sprocket haha so that's another thing i need to look at although I doubt it's related to the stalling.

I've got all tomorrow to go over it if I find the culprit I'll report back!

[Rhinoman]

Thats not a good sign you may have trashed the crank keyway.

[Marko_SJ]

To suggest a dumb one but you didn't take the carb off and forget to re-connect the fuel cutoff solendoid did ya?

I did that and then a potential buyer came and looked at it

[jimmyjimny]

lol nah I left the carb on the manifold haha cbf taking it off, with the metal shavings the keyway looks fine I think it's leaking oil from the crank seal and maybe those shavings have come out from the block if that's possible, The bottom end did seize or get stopped by a valve when I was doing the head and I remember some not too nice noises when it unseized
s possible the metal shavings could be from that... I just did a compression test and it read

1. 162psi
2. 157psi
3.155psi
4.143psi

I think number 4 is a bit on the low side but not sure if this means stuffed valves or not. I'm worried where these shavings have come from I'm just trying to crack the crank bolt atm and check the seal but even with a chain wrench I can't get it to budge (using a shiteload of force) so I think I need to get a rattle gun or something... **** this car lol