bronco

[bruce billings]

i have an 89 full size bronco that has an engine miss that seem to be worse in the summer months .it acts like the motor is shutting down but the rpm speed do not change .i have tried plugs ,wires ,rotor, cap ,distributer,fuel pumps , fuel filters .i even had it on a dignostic machine and it showed nothing , do you have any ideas that could help me. the bronco has 118,500 miles , the has been there since i have owned it.i have owned it since august of 98. thanks bruce billings

[vetteonr]

You mentioned you replaced the distributor, did you replace the ignition module as well? Those darn things have been known to act up when the temperature changes. I've had it happen to me twice. A diagnostic check won't find it if it's not acting up at the time. Just a thought.

[bruce billings]

yes it was replaced when the diognastic was done still doing it

[towtrucks]

How about the timing chain. That is alot of miles on a chain.
Remove the spark plugs. Turning the engine clockwise with a pull handle on the harmonic balancer, stop at TDC. (top dead center) Then remove the distributor cap. Then turn the engine COUNTER clockwise until the rotor button begins to move. Then see where the timing mark is. That will tell you the amount of degrees of slack is in the chain. DON'T be surprised if the timing mark goes beyond the degree mark.

[bruce billings]

if i was to replace the timing chain and it didnt help then what .it is becoming a pain ,it was worse when i lived out west . i have had a very good mechanic work on it and no luck

[Trader Ray]

A point when you evaluate what you have and what it is worth to you. The timing chain suggestion was right on the mark ( no pun intended, yea right) There should be a direct responce between the balancer and the rotor when using the tip that towtrucks mentioned. I was in the used auto parts buisness for awhile and it was unreal how many Ford timing chain covers were needed because of the slop in the chain, it would wear throught the covers and cause a oil leak that could not be found. This was a real common problem on the 460 engine especially.

[bruce billings]

i will have to keep that in mind ,for the spring jobs on the bronco . to cold to work on it now .thanks

[Trader Ray]

Living in Maine, I would have to agree with you. burrrr

[Daniel Wood]

You said you replaced the module, did you replace the pickup coal inside the distributor?

[bruce billings]

it was replaced when i had the bronco put on a diog machine, by the tech

[danny]

has a compression test been performed?

[bruce billings]

that i cant tell you

[Daniel Wood]

[QUOTE]Originally posted by bruce billings
[B]i have an 89 full size bronco that has an engine miss that seem to be worse in the summer months .it acts like the motor is shutting down but the rpm speed do not change .the bronco has 118,500 miles , the has been there since i have owned it.


just out of curiosity try this, see if you can disconnect the exhaust pipe in front of the catalytic converter that is if it doesn't have a sensor. And drive it, you may have a sort of stopped up exhaust system making it sound like the engine shutting down. However this doesn't explain the engine miss. I worked on a trunk one time that ran perfect idling and while driving as long as you didn't accelerate fast you were okay until you reach the speed around 60. It was just a freak accident that I found it. I'll admit it this is just a while guess. But it fixed my problem

[danny]

i asked a local muffler shop about changing the cat on my '91 chev p/u. the mech asked me if the truck would do over 60 mph, i replied yes and he told me to not worry about it that at even at 20% clogged the truck wouldn't see anything over 60-just some info

[bruce billings]

it did not have a cat on it when i bought it .then i put a 3 inch exhaust on it ,no diff execpt in power