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Chevy 350 Will Not Start


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Posted

Hello All,<P>I know this might not be the correct area, but I need to get this thing running ASAP so please help me....<P>Thanks<BR>David<P>Sorry to bother you with this question, I was hoping you might have an answer. I have a 1986 Chevy suburban with a 350 4 BBL carb, automatic Trans, with air. It has (had) that electric Rochester quadrajunk carb, read below to see why the carb is replaced. <P>I need to get it going ASAP, as this is my transportation to Ohio. I am in the Air Force and am getting stationed there and need to be there by 15 Jan 00.<P>My sister let me have this thing to drive from Oregon to Ohio. My Father has been trying to get it road ready for me for a few weeks now while I have been stationed in Japan and he has sunk almost $500.00 into a supposedly running truck.<P>First it would run like crap and then it would not run at all. When it ran it would not rev past 2000 RPM's, even floored. Then it would not start at all. My Dad changed the spark plug wires, no start, he then changed the spark plugs, and it started right up but missed and popped and backfired all the time. Basically ran like crap, but would rev up as needed past 2000 RPM?s.<P>I e-mailed him to check the timing chain as it might have slipped. He did and the thing was pretty bad, so he replaced it, it started right up but still ran like crap.<P>He checked the carb (the 1986 has the electric controlled quadrajunk) looked inside, kind of dirty, cleaned it out, put it back together and reinstalled it. Would start, but still ran crappy.<P>The past few days it won't start, leaks fuel right into the intake, floods it out bad, fuel pours out of the number 7 and 8 cylinders if you remove the spark plugs.<P>Bought a brand new Holly 600 with elec. choke for $239.00. (Rebuilt quadrajunk is from over $420.00 to $500.00 + depending where you go). Put it on, got the basic vacuum lines hooked up, the rest on the carb is capped off, but the some of engines vacuum lines are not. <P>Try to start, the engine back fired through the Holly carb real bad. Check the timing, when #1 is at TDC (at compression) rotor points to #6, so I figure 180 degrees out. My Father has not touched the Distributor at all; he changed timing gear with pistons at TDC. Matches dots on gears as well, when lower up and upper down, #6 at TDC. When lower gear dot up and upper gear dot up, #1 TDC.<P>I turn distributor 180 and now turns over, but no start no backfire as well. <P>Don't know if timing gear installed correctly now or not since distributor <P>I have pulled all the plugs, dried them off, and checked the gap, ok. Turned the engine over a few times to blow the excess fuel out of the cylinders. Let them dry over night.<P>Performed compression check of all the cylinders, running at about average of 135 to 150 psi per hole, (it is the hold on tester so not to accurate).<P>Double / triple check all the wires to make sure they are routed correctly. <P>When try to start seems to be firing, but won't take off. <P>I am not a Chevy expert (Into Pontiacs). Would you have any suggestions?<P>Thanks<P>David<BR>

Posted

I think part of your problem is the way the timing chain is installed. On the no. 1 TDC position (compression stroke), the crank and cam gear marks should match on the inside (cam gear mark should be on bottom and crank gear mark should be on top). Distributor/rotor should be pointing to no. 1. If the distributor was not removed, it should still be in alignment with the cam.<P>According to your description, your timing chain may be installed 180 degrees off.<P>Also check your plug wires to be sure the routing is correct and matches firing order (I believe 1-8-4-3-6-5-7-2 is still correct for this model year).<P>Worst case sceneraio is that the timing chain slipped and a valve (or valves) contacted pistons. This could have resulted in bent valves or pushrods. Compression check would indicate bent valve. Bent pushrod would have to be found by removing valve covers and checking one by one.<P>Also, proper way to check compression is to remove all sparks plugs and check cylinders one at a time.<P>If you don't have one already, get a service manual for your vehicle (I suggest Haynes). Any local auto parts store should have one of these. All such items mentioned here will be found there (good troubleshooting charts, etc.).

Posted

David;<BR>The symptoms you describe indicate a sheared roll pin in the distributor gear. The pin usually shears with a jagged edge which allows it to catch occasionally and run ok after you've set the timing, but it will shortly slip again. Believe me on this I speak from experience.<BR>On the matter of the timing chain GM's are pretty much a no brainer. You can either align the dots both on top dead center of the gears or the crank gear on top and the cam gear on the bottom (since the crank rotates twice and the cam only once).<BR>After you've fixed the dist. put #1 cyl. on TDC(both valves closed)and drop the dist. in so that the rotor is pointing to the #1 plug wire.This should get you close enough for the engine to start.<BR>Good luck

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