Guest DatsuNoob Posted June 24, 2007 Report Share Posted June 24, 2007 SO today I was out driving the 620 breaking in the new exhaust, when my truck started driving very sluggish. It's extremely slow in acceleration, gas mileage is terrible, acts like it doesn't wanna start unless I gas the shit out of it and idles poorly. I put a new weber on a while ago and thought I had the mix good yesterday, but today it's running like shit. Any ideas :confused: Quote Link to comment
ggzilla Posted June 24, 2007 Report Share Posted June 24, 2007 Always start with the basics: Fuel and Spark. Spark: Is the spark strong? If you have points, are they over a year old? Is one of the spark plug wires burnt or cracked? Fuel: Is the fuel filter clogged? At idle does the fuel level come up to the dot on the glass? Engine Troubleshooting Overview -- feel free to add/modify it. Quote Link to comment
datzenmike Posted June 25, 2007 Report Share Posted June 25, 2007 It's a Weber and sensitive to excessive fuel pressure I believe. Quote Link to comment
Icehouse Posted June 25, 2007 Report Share Posted June 25, 2007 Is the carb still tight? when the base plate bolts loosen it will run like shit. Grab on to the carb and make sure it is tightly bolted to the intake manifold. Quote Link to comment
521Lvr Posted June 25, 2007 Report Share Posted June 25, 2007 if you have a choke butterfly it might be closing on you. make sure it is fully open after warm up. Quote Link to comment
Guest DatsuNoob Posted June 25, 2007 Report Share Posted June 25, 2007 It has brand new wires, fuel filter, cap, rotor, carb base plate is tight. It sounds like it has a dead cylinder. What would cause this? Is there a way to "wake it up" HAHA? Quote Link to comment
Duke Posted June 25, 2007 Report Share Posted June 25, 2007 It has brand new wires, fuel filter, cap, rotor, carb base plate is tight. It sounds like it has a dead cylinder. What would cause this? Is there a way to "wake it up" HAHA? Pull the plugs and see what they look like. If you really think a cylinder isn't firing it would be really rough at idle and just generally sound like shit. Checking the plugs will tell you if something is leaking into a cylinder and causing it not to fire. Quote Link to comment
Guest DatsuNoob Posted June 25, 2007 Report Share Posted June 25, 2007 Ever hear of a bad distributor causing one cylinder not to fire? Everything else is okay I believe. Timing was set at 10 degrees. But stock setting is 10 deg. B.T.D.C., how do I get that instead of just 10 deg? About to go mess with it before tring to drive to work. I'll get back to you guys tonight, thanks. Quote Link to comment
Bleach Posted June 25, 2007 Report Share Posted June 25, 2007 10 deg is 10 BTDC. You probably do have a leak at the base. Even if the carb is tight to the adaptor, the adaptor might be coming loose. Quote Link to comment
sjeff64 Posted June 25, 2007 Report Share Posted June 25, 2007 if you just put on new exhaust are you sure you didnt mess up one of the holes on the intake/exhaust gasket?that is the one bad ting about mated gaskets Quote Link to comment
banzai510(hainz) Posted June 25, 2007 Report Share Posted June 25, 2007 How about changing the spark plug again???????????? Pull th plug wires till you know which one is not firing. Do as the others said Ck the choke also, Ck mixture. I thought ids wasnt all that good when I left the last time shold have reved up faster. I think something was still wrong Quote Link to comment
DISLEXICDIME Posted June 25, 2007 Report Share Posted June 25, 2007 one time my number one spark plug come loose in the head and did this same thing. I thought it was a bad plug wire. So i grab the # 1 wire while the car was running and wigeld it to see if it was on all the way and air shot out from around the plug so just to be safe i changed the plugs and it has not happend since Quote Link to comment
datsun dreamer Posted October 20, 2007 Report Share Posted October 20, 2007 bringing out a old post!! this morning i'm driving my '74 to work and it starts to sputter and hesitate, i get the truck to my work and i try to start it and it turns but does not start...so i pull the distributor off and crank the engine and my rotor is turning so i know my timing chain is o.k! I put the distributor back on and it fires right up but it still is sputtering now my tach is now going crazy:eek: Any suggestions???? Maybe bad points,plugs or fuel pump? Quote Link to comment
]2eDeYe Posted October 20, 2007 Report Share Posted October 20, 2007 Sounds like points...maybe they got pitted. Quote Link to comment
datsun dreamer Posted October 20, 2007 Report Share Posted October 20, 2007 I'm thinking the same thing! My cap and rotor are a little pitted as well.....I'll change everything and hopefully problem solved:D the carb was "popping" when i gave it gas....Could this be faulty points as well????? Quote Link to comment
jesusno2 Posted October 20, 2007 Report Share Posted October 20, 2007 I had a 620 with simular problems once it did exactly as stated, like a cylinder would go dead. eventually I started testing my ignition with a meter and eventually found that my coil would just decide to lose voltage every now and then like it had a short. so i replaced the coil and it fixed the problem. Quote Link to comment
datzenmike Posted October 20, 2007 Report Share Posted October 20, 2007 bringing out a old post!! this morning i'm driving my '74 to work and it starts to sputter and hesitate, i get the truck to my work and i try to start it and it turns but does not start...so i pull the distributor off and crank the engine and my rotor is turning so i know my timing chain is o.k! I put the distributor back on and it fires right up but it still is sputtering now my tach is now going crazy:eek: Any suggestions???? Maybe bad points,plugs or fuel pump? Actually the distributor/oil pump spindle is driven off a gear on the crankshaft, independent of the timing chain. Shows your thinking at least, not like many car owners to-day that are at the mercy of technology. If you pull the cap off the valve cover and look inside while cranking you'll see directly if the cam in turning. The erratic tach is a classic symptom of a miss firing system. A fouled plug or a loose high tension wire won't cause this, as it's in the secondary voltage system. The tach gets it's signal from the points or the EI primary system. If, however there is a loose wire to, or in, the distributor, or to the coil, or the points are intermittently making bad contact, or even a coil that has is going bad, (usually an open condition where no current flows) is this will directly affect the tach reading. If you have points, it's probably that. It is a high wear area. Check that the distributor is properly grounded. The power from the coil must pass through the points to ground on the distributor body, and it has to be grounded to the block to complete the circuit back to the battery. Quote Link to comment
datsun dreamer Posted October 21, 2007 Report Share Posted October 21, 2007 :rolleyes: Thanks for the info. everybody:D, I replaced the points, plugs,cap/rotor and adjusted the carb! seems to be running smoother with no hesitation now! Still a issue with idle speed on the carb......I'm guessing this is a choke problem and autozone does not carry weber parts so i will have to search for a high performance parts dealer or the net. Quote Link to comment
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