1976 maverick won't start

Did you check the chain? The easiest way is to take the distributor cap off and see how many degrees you can turn the crank by hand before the rotor moves. I forget what is considered bad, but the bigger this value (measure with the timing marks on the crank and block) the greater the slack.

Is this a known working carb? If not you've just increased the variability of what you are dealing with.

The ignition timing would be off, about 6 degrees retard, though it should still start.

Does it start up without you dumping fuel directly into the carb?

Check that the carb float and the valve it actuates are moving. If it's stuck closed it won't get any fuel to the engine. Also check the carb settings. They could be way off since you swapped it in. If you still have the one that was removed and it seems ok and hasn't been changed setting wise, putting it back on may get it going.

Check the chain and the carb.

The carb is not set up properly. R&R and check out the instructions in a rebuild kit.

First check that the carb is getting gas. When you push the throttle does the accelerator pump work and squirt gas down the barrels? If not check that the accelerator pump linkage is working properly. If it is, remove the top of the carb and ensure that the fuel bowl is filled with fuel. If not you probably have a float/needle problem... Fix it, fill the bowl with gas and put the top back on.

Only after the carb appears to be working correctly should you move on.

The backfiring should not happen... Move #1 cyl to TDC, and ensure rotor is pointed at the correct pole and wires go to correct cylinders. Then twist the distributor base until the rotor is slightly after the #1 pole, not dead on. This is because it should fire a few degrees before TDC. It should still run with retarded timing, but will be rough and may backfire through the carb if too far advanced or retarded.

Also, put new points and condenser in if you haven't already, as this could result in backfiring and hard starting (no good if it's barely running as it is).

Also, adjust your valves. If your rocker arms are too tight an intake valve could be slightly open when the cylinder fires, resulting in backfiring through the carb (I had this problem recently, despite setting them as the manual describes). If you have standard hydraulic lifters and non-positive stop (i.e. adjustable) rockers you should adjust each rocker when it is flat on the cam, not on a lobe. Tighten the nut until you just can't twist the pushrod with your fingers, then 1/4 - 1/2 turn more. I would not do the last

1/4 to 1/2 turn until after you get the engine running to ensure that you are not going too tight.

If that doesn't do it then perhaps the timing chain or gears are bad or jumped a tooth. A jumped tooth could result in backfiring and rough running, especially if there are other problems with the engine. Do like Brent suggested to check how much slack is in the chain.

Cory

Pat Wright wrote:

Run a compression check. If the chain has slipped, all cylinders will show little or no pressure. It sounds like the chain has slipped, very common on pre

Ok I'll try and post answers to most of the questions at once. I have run compression and got more than nothing. Not promisingly high but more than nothing.

Remember to set to zero by turning it backwards a bit, that allows the slack to be measured accurately when turning forward.

"not promisingly high but more than nothing" means? What is the pressure reading? How did you do the test? Hopefully battery charger installed to battery, all plugs removed and throttle held wide open, five strokes per cylinder. Low pressure on all cylinders means you have mechanical problems. Your next thing to do is find out why you have low pressure readings. The most common and most likely is the timing chain. Trying to mess with the fuel delivery system is not where you should be at this point.

I've gotten many good suggestions and unfortunately working on the car for me is not an easy task so Here's the only new thing i have tried. I went to the original carb basically in original setup(i didn't mess with any screws or anything on it) I took the top off and filled the float with gas and it did squirt gas out of the nozzles both on and off the car when i tested it. I put back on the car. the fuel filter on the carb is wide open(has a hole poked in it) so i put it back on gave it a few cranks and it tried to start just like before and again even with gas getting in it from my pumping i got the backfire flame and a lovely little fire in the carb. :) Quickly extinquished of course. So at this point i'm going to start back down the list probably with seeing how far the distributor is off. Although part of me just says to pull the chain everything points to it so far. Comments? Sorry i haven't tried more i'm just getting over being sick and i didn't get much done over the holiday weekend. Thanks for the help.

Pat oh ya the compression was done witha compression tester in the cylinders. they got to between 60-90 on all cylinders i believe. Thanks

Two carbs, same results, good odds its not the carb. Most likely the chain has skipped a tooth, you can pull the cover and check the marks.

That if memory serves me is rather low. Sounds like it needs a rebuild.

The compression is low, but not surprising considering the age of the vehicle. Is the motor original? and how many miles? Set the timing to TDC by popping #1 spark plug and slipping in a screwdriver. Gently turn it over by hand until the TDC mark is coming up, then watch the screwdriver to get to exactly TDC. Pop the valve cover and be sure both valves are fully closed. (You can be out by 1 crank revolution otherwise.) Set the distributor so that the rotor is pointing at #1 plug wire, or a hair before it. If it still backfires through the carb, check the timing chain.

Low compression all across, backfires....

Classic timing chain tooth jump.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Pat Wright wrote: