yamayuki98

i recently purchase a 86 toyota pickup 2wd with original aisin db carb. truck had a blown head gasket at time of purchase but still fired up. towed truck home, took engine out, replaced gasket and head because old head was bad. head resurface, new head gasket and head bolts. set timing following this site: http://www.4crawler.com/4x4/CheapTri...ingChain.shtml
truck would crank but wont start. checked for spark, both igniter and spark plug sparks. checked for gas from gas line checked out fine. check carb for gas, carb checked out. the our glass shows gas half full.

here is my problem: i get gas into the carb i just cant get gas into the manifold/engine. i started fooling around with the distributor timing and somehow got the carb to back fire (gas would purge back out of carb). im stump at this point. anyone have any suggestion what it might be. i haven't checked the compression yet but could there be a possibility that i have bent valves. could this cause the engine to loose compression through the intake side causing the backfire through the carb. i need to get this truck running this week if anyone can help i would greatly appreciate this.

ps: spark plug is dry when i try cranking it. no smell or residue of gasoline visible on sparkplug.

fdp101452

Im not familiar with the Toyota carb, but have worked on carbs in years past, thats all we had then. My guess is your accelarator pump in the carb is not working. Without trying to start it, work the throtle and look down inside the throat of the carb. Does the butterfly open? You should see gas squirt into the throat of the carb at the same time. If you dont see gas, your accelarator pump in the carb is either not working or the orface it squirts through is clogged up. If the truck set for awhile before you got it, chances are the gas dried up in the carb and clogged the orfice. Repair involves getting a carb kit and soaking the dissassembled carb in carb cleaner. Carb cleaner is fairly expensive and so if you can find a mechanic {probably and old one} maybe he could clean and rebuild your carb for you. Its not hard, but some knowledge of how a carb works would help a lot Just work the throttle while looking down the throat of the carb and that will tell you what you need to know.....regards.....Rick

Rippinthewaves

Check that the float in the carburetor is not stuck. Rap it with a mallet or wood to free it up. I'd rebuild the carb.

yamayuki98

i actually had the carb off. i believe the accelerator works becausethe butterfly does open. i actually attempted pouring gas down the carb and then cranking it but chambers dont show any signs of gasoline going inside. it just seems to dried up. i mean if i had spark pouring the gas down the carb should get gas into the combustion chamber giving me at least a start or choke but nothing happens. and like i said the gas purges back out. what would cause that? thanks for the suggestion keep them coming.

yoterr

dist being 180* out, you might have had it on TDC on the exhaust stroke when you set the initial timing, you shouldent be able to get it to backfire with just the timing limits of the dist, also did you set your valve clearances? you should do it hot, but if there is no clearance it would be holding a valve or 2 open thus making it backfire, pull the valve cover and check the clearances per FSM set it cold, then if you get it to run re-set them hot

yamayuki98

okay, im going to try and set the valve clearance cold as fsm states because since i cant warm it up im out of luck. but as for the initial dist. timing setup im pretty sure i set it up correctly. but as you stated i do realize that looking at the cam it seems as though at tdc the exhaust cam lobe is going to open first as the piston draws in vac. exhaust cam lobe seems to be at 8'oclock and intake at 4'oclock. is it wrong. should the intake be at 10'oclock and the exhaust be at 2'oclock at zero degree timing with piston 1 being tdc. this is getting exciting for me but at the same time a pain. also i dont see carb squirting any type of gas at all. it purge or prime with the accelerated press but no gas whats so ever. i will try not tomorrow but on thursday to check compression, set valve clearance and re-time the cam and piston. any other suggestions welcome. thanks in advance

yamayuki98

got it running. thanks everyone and especially (yoterr) you were right on. i was losing compression because the intake vlave were stuck open due to valve clearance. after i adjusted those and manually prime the carb truck fired right up. thanks for all the suggestions.