I have a 1976 ford Maverick 4dr with a 302 2v. It sat for about 2
years in a junk yard and the guy i bought it from said the only major
problem was the timing chain was not good anymore. Basically i've
done all the standard things you would do to a car that has been
sitting. I couldn't get it to start at all first so i replaced the
solenoid and the starter. Then replaced the fuel pump and now have a
different carb on it another motorcraft 2100 2v. Basically my problem
is this I've Checked that when the #1 piston is at TDC then the cap is
pointing to 1 on the distributor. What happens is that i dump either
gas or starter fluid directly into the carberurator<sp?> and it starts
basically on the first turn but then within a second or two
immediately shoots flame through the carb and dies.
This pretty much happens everytime. We can't keep it running to save
our life. We originally thought it wasn't getting enough gas but we
pulled the hose going into the carb and it shoots out gas when you
turn the engine over. We also poked a hole through the fuel filter to
make sure that it was going through there and it still does this. I
still have not replaced the timing chain because i want to make sure
it's nothing else before i do that.
My friend said possibly a bad intake valve? Could this stop it from
running entirely? I have had the valve covers off and turned the
engine manually and watched the rods and valves go up and down. I
don't remember checking every single one but i know they were moving.
I have replaced all the plugs also and the wires were new before it
was parked there is spark for sure i've verified that. So should i go
for the timing chain and replace it or is it something else that could
be much worse? This engine is original to the car. Thanks for any
help anyone can give.
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
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.
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
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.
Pat Wright wrote:
"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
oh ya the compression was done witha compression tester in the
cylinders. they got to between 60-90 on all cylinders i believe.
On 8-Jul-2003, firstname.lastname@example.org (Pat Wright) wrote:
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.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.