View Full Version : 1986 350 no start :( pls help

07-26-2012, 04:22 PM
Ok timing chain went I was told. Then they put new sprockets and new chain on. After 350 would not start and even with rebuilt dist and worked by mechanic for 3 hours still no start. So buddy pd mechanic for rebuilt dist. So today I took timing chain off and it appears dots on gears line up. My next thing to do is comp test since was told valves may gotten bent. Previous mechanic found 3 cyl to be about 100 psi yet would not check other 5 until he got paid for rebuilding dist and timing it and everything. So engine pops and farts and even with dist in right spot and not 180 out is just pops and farts. Any ideas other than doing comp test? I expect camshaft sprocket can only go on in one place since it has a dowel to line it up or are there other holes for dowel? I was thinking of taking camshaft sprocket off to see...

07-26-2012, 04:44 PM
sounds like the chain is out 1 tooth. The dots may line up but make sure there is only slack on the tensioner side, not on the other side, otherwise the cam and crank will be out 1 tooth

07-26-2012, 04:52 PM
Pull the valve covers and crank the motor and see if all the lifters are moveing

07-26-2012, 09:29 PM
Crank the engine over with a bar till you see Cylinder 6 exhaust valve close and intake is about to open that is exactly when #1 should fire. Both 1 and 6 should be at TDC but only number 1 is firing.

07-27-2012, 09:36 AM
Thanks for pointers. Ill take pic of sprockets and chain today.

07-27-2012, 07:01 PM
Looks like marks line up perfectly yet how do you know which valves are exhaust or intake? I took valve covers off and guessed exhaust valves would line up with exhaust manifolds. Could a vacuum leak such as under carb cause it not to start and only pop or fart?

07-27-2012, 07:12 PM
From the front It goes Exhaust, Intake, Intake, Exhaust, Exhaust, Intake, Intake, Exhaust

07-27-2012, 07:16 PM
Thanks! Just loaded a pic of timing gears...

07-27-2012, 07:20 PM
U actually got firing order right on the cap and starting in the right spot?

07-28-2012, 01:11 PM
If the truck was running and then started doing this if you have the valve covers off check your lifters mine did a similiar thing last year and it had a lifter come apart don't like telling you the next part but it did a lot of internal damage hope you have better luck than i did just a quick check Good luck

07-28-2012, 11:24 PM
Umm got gas? :D But seriously, popping/backfiring can be caused by too lean (no fuel) or retarded timing. Look down the carb while pumping the throttle (while NOT cranking the engine). Should see good shots of gas shoot from the accelerator pump ports.

07-28-2012, 11:48 PM
just a stupid question is distrubutor out 180 deg ?

07-29-2012, 08:49 PM
Already checked dist and the 180 thing weeks ago. Normally an engine will run a bit when you put gas down carb and we did this a while back but starting tommorow I'll recheck everything... Compression test (dry) averaged 100 psi per cylinder however some as low as 80 and one at 75.

07-29-2012, 08:55 PM
side of chain that should be under tension is right side (drivers side)? crank turns clockwise...

07-29-2012, 09:12 PM
Was it running before and you did some work to it and now it won't start?

07-29-2012, 09:33 PM
Do another compression test this time put a couple squirts of motor oil into the piston if it goes up then ur rings are the problem if it stays the same u have problems with the heads

07-29-2012, 10:06 PM
flat camshaft?

07-30-2012, 09:15 AM
I was thinking camshaft. The story behind it was it was running fine in Spring 2011 and then one day the engine just locked up. I'm just going by what I was told my buddy Gary told me. So engine locked up so the previous owner to my buddy Gary took timing cover off and replaced timing gears and chain. After replacing gears and chain it would not run... just pop and fart. Gary then bought it off the guy really cheap for his kid to fix up. They then had another mechanic rebuild dist who also tried to time it. Still it would not run so I traded a 2wd pick-up to Gary for this non running 4x4. I figured the guy that replaced gears\chain made a assembly mistake. At the very least I could put another engine in it.

So today I'll check movement of lifters in relation to timing gears and see if I can see anything else wrong. If cylinder psi is all over 80+ I would expect it to still run?? Could pistons possibly have bent valves or maybe bent pushrods? What commonly occurs to a 350 when timing chain skips or breaks? Can the chain break? I'll do another comp test too.

07-30-2012, 09:25 AM
Just to add myself and mechanic who rebuilt dist checked firing order and timing multiple times. I'm thinking internal engine damage like bent valves yet if valves bent wouldnt there be no compression in cylinder? Or bent push rods cause valves not to open fully?

07-30-2012, 01:40 PM
Well compression goes up with oil added to cylinder so rings worn. I'll post #'s later. Turned engine over till intake on #6 was about to open and O stamped on cam gear at 12 o'clock.. #1 about to fire. Appears dist needs to go back a notch. It wont drop completely so figure oil pump needs to be turned slightly with big flat screwdriver. I'll try that after lunch. I think plug wires were all moved ahead a post on cap but I'll know for sure once I put everything back together. I'll check plug wires for resistance too (8 ohms/foot).

07-30-2012, 02:24 PM
fak it.. its a small block.. buy a runner for 400$

07-30-2012, 03:05 PM
Looks like marks line up perfectly yet how do you know which valves are exhaust or intake? I took valve covers off and guessed exhaust valves would line up with exhaust manifolds. Could a vacuum leak such as under carb cause it not to start and only pop or fart?

And that's where you lost me. [1b]maybe you shouldn't be doing this.

07-30-2012, 04:25 PM
small valves intake larger exhaust normally and if a valve is bent and not seating properly yes u can lose compression but it sounds to me u should start basic u got fuel yes you got comp yes spark yes but do u have spark at right cyclinder and do u got exhaust im gunna say yes your timing has an issue put it to tdc with a rod in #1 cyclinder piston should rise all the way to top then pull out rod and see if you are timed correctly if u line up at the same time look at cap and rotor should also be #1 make sure plug wires are correct and if u got air fuel comp exhuast it should run!!! if not then u got lose of compression somewhere or ur valves arent opening (camshaft). it takes a major air leak to make a motor not run so i doubt its a intake issue and for fuel make sure u got fuel through carb not just at line! try that let me now if it helps!

07-30-2012, 04:38 PM
Ok all finished it runs! Now just to buy gas for fuel tank. After I turned oil pump with screw driver dist popped right in. Had to turn dist CW to have it run for a few seconds. Dumped gas in carb since tanks empty so hope to have it running good by wed. Thnks for all the help.

Now as for the mess of vacuum lines. Looks like thing screwed into thermostat housing has a 2 of 4 plastic lines busted off it. Cant i just disconnect some of this stuff especially since no air care up here? Just run dist vacuum line to metal line on front of bottom or top of carb? EGR valve just disconnect it? On another v8 I had we just made a plate to go over spot where egr was.

I'll look into thing on top of thermostat housing....$ wise.

07-30-2012, 06:38 PM
Tell ur buddy to find a good runner for when it does pack it in he will have something to replace it with. Glad yea figured it out

08-02-2012, 10:07 PM
Just unplug the vac line from the EGR, as long as it's not stuck open it'll run fine. Run the vac advance to a manifold vacuum port on the carb for best fuel economy.

08-03-2012, 09:31 AM
Thanks Kootenaycat!

08-03-2012, 05:28 PM
Darn thing wont run!! After wet compression test a few nights ago it ran for a few seconds. Compression test was

cyl dry wet
1 100 125
2 70 105
3 100 150
4 70 100
5 75 85
6 90 150
7 120 145
8 105 did not do

I figure it only ran for a few seconds cause oil was helping with compression. Yah accelerator pump is not working either and no filter in carb so figure carb is full of sh*t.

I know dist is pointing in right direction. rotor points at cyl 1 on #1 tdc comp stroke and ROTOR POINTS TO PLUG 1 ON CAP. This was done with timing chain cover off and mark on cam gear at 12:00. Timing of gears was good see previous pic. I've done enough successful timings of 350's to know it should run.

I figure next week compare it to another 350 I got that runs good. A friend on the phone told me today that it sounds like engine is just plain worn out. I never seen it run before and only info I got to go on engine locked up and timing gears\chain were re&re`d.

As for today if you dump some gas in carb the engine fires every couple seconds as you crank it over. I figure try the dist\plug wires\and plugs and carb I got in another 350 yet maybe I'm just wasting my time. Not sure what else I can do.

I also have a 305 I can put in it that runs to at least get truck mobile to sell. OR drop 700R4\t-case out of it to put in my 81 Jimmy Mud Truck.

08-03-2012, 10:24 PM
is the hei grounding out?

08-03-2012, 10:29 PM
is the hei grounding out?
It grounds through the motor.............
Only needs a 12v ignition source to run
Rebuild or swap it out rings are gone or there is more damage then u can see.

08-03-2012, 10:43 PM
I agree with 85chevy, pull it and find what's worn/broken inside or put a known good engine in. Those compressions numbers are too low!

08-03-2012, 10:46 PM
I agree with 85chevy, pull it and find what's worn/broken inside or put a known good engine in. Those compressions numbers are too low!
I can't remember the number off hand but I think they should all be within 15 PSI and even that is a lot but u should be at like 150 PSI on a rebuild

08-03-2012, 10:50 PM
inconsistant connection from motor vibration

08-03-2012, 10:58 PM
They usually work or they don't all it really does is turn on and off

08-09-2012, 10:00 PM
thanks guys. Ill keep you posted...

02-20-2013, 09:12 PM
350 looks like it is a 305.... T9K code on block under alternator, and 305 heads, maybe cam worn out too. Hope to have it out next week and pull heads etc... I was thinking Rays comment
inconsistant connection from motor vibration
maybe 4 pin connector from dist. to firewall, that goes to an ecu or something. But with compression low and so uneven which skyrockets on wet test I still think rings siezed or shot....

Either way V8 is coming out and then taking out 700R4/NP208 TO PUT IN MY 81 Jimmy since need tranny for it.... I'm wondering who in BC can rebuild a 700R4 with one of those monster mudder kits advertised (or similar) on "TruckTV". I even wonder if I could install on of those kits?? Looked like on Truck TV you need a few special auto tranny rebuild tools...

02-21-2013, 12:23 AM
Umm if you have problems figuring out a carbed small block
Don't even think of trying to build a auto trans
It will be a waste of a bunch of exspensive parts
Not trying to insult you but I won't try a 700r
And I'm fairly proficient at a powerglyde
And if that motor locked up it wasn't valve timing causing it
Most if not all American v8 are non interference motors
The valves will not hit pistons
Severe overheating
lack of oil
Or hydraulic caused by excessive fuel or water down carb
Could seize it all these can cause severe damage
Pinched or scored rings and cylinder walls
bent rods cracked pistons
I have seen a cylinder pushed out of round by water getting compressed
Have seen cylinder walls cracked from it to

02-21-2013, 06:22 PM
Yup an automatic transmissions needs to be rebuilt in a very clean enviroment

02-28-2013, 05:13 PM
Thanks for all the ideas. 305 still in but hope to get it out tomorrow or next week....

02-28-2013, 07:40 PM
get a new motor ,dont wast your time rebuilding a 305 they have a very weak bottom end and are garbage [cheers]

02-28-2013, 07:43 PM
get a new motor ,dont wast your time rebuilding a 305 they have a very weak bottom end and are garbage [cheers]
Its the same bottum end as a Chevy 350:dontknow: just a smaller bore

03-06-2013, 09:47 AM
Well 305 is going to be set aside. I pulled out 700R4\NP208 to put in my 81 Jimmy for now. Its got a good 305 in it yet I have a sb 400 I may put in later in the summer...