Bronco Forum - Full Size Ford Bronco Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
1,240 Posts
Discussion Starter #1
Hi-
With the warmer weather my Bronco hasn't been acting right lately. I have done the six litre tune-up and all ignition parts are new including a new motorcraft coil. I used Motorcraft Platinum plugs though. I originally had the timing set to 12.5 with .042 spark plug gap during the winter and the power increases were pretty enormous. As the weather has been warming up, it has been really been affecting the Bronco. When I pulled the plugs and gapped them out, it was hard to tell if I gained power or not. I might have lost power from gapping the plugs to .055, as well as the engine didn't sound as healthy as before. I for sure lost torque. I tried advancing the timing to 13.5 and I think its even worse now. It almost sounds as if the engine is running under water. Okay, a couple concerns I have. One is the spark plug boots didn't seem to go on right, I think I got them all back on okay. Two, the distributor cap dosen't fit on tightly, with the hold down clips in place, I can move the distributor cap up and down when I pull on one of the wires. Then, of course im concerned about the plugs and wires not being up to par. As well as the timing being too advanced. Im not getting any pinging, maybe a minimal amount, but im suspecting that I might be losing power as a result of advanced timing. The other thing is the has burned oil from day 1. The plugs were perfect and not fouled at all when I pulled them, but I may have compression issues, since the valve seals were replaced, so I suspect the piston rings. But, I only burn a quart every 1,000 miles. If I burn oil, what gap and timing should I use? Im hoping not to have to pull my plugs again.
Thanks-
 

·
Registered
Joined
·
1,383 Posts
Put ur plugs back like they were and set timing back to 11.5
 

·
Registered
Joined
·
1,240 Posts
Discussion Starter #5
What about the distributor cap being loose or the plug wires not being on fully? I want to make sure of these simpler things before pulling my plugs out again. Im still wondering if this could be a timing issue. Because in neutral if I rev, it sounds like a very healthy engine. But, when it gets a load (in gear), it lacks power until the vehicle is up to speed. Once the truck is above say 35-45 mph, the engine has plenty of power. But, from a stand-still up to that speed, its lacking a good bit of power. And its really bad today because its 90 degrees outside. Another thing I should mention, when the truck had the plugs gapped at the stock .042 and was at 12.5 degrees timing. To pull the truck itself, it had plenty of power, but once I hooked up a trailer and was towing a load, the engine started doing the same sort of things. And towing something was causing it to ping and it took a quarter of a tank to go 10 miles. Should I try dropping the timing first? I really don't want to have to pull the plugs again. Also, what about wire routing and the wires touching anything metal? Can they ground out through the insulation?
Thanks-
 

·
Registered
Joined
·
1,383 Posts
Take a picture of your dizzy. I don't understand how with cap on and clamped it could still move. Could be poor contact in dizzy. Plug wires should "click" onto the plugs.
 

·
Registered
Joined
·
1,240 Posts
Discussion Starter #7
Theres also the possibility of a plugged cat also, which ive been suspecting. But, this is definitely something in the ignition system. Don't think its the dizzy cap because it was doing this before the new cap and rotor and the old one was loose too. What about the wire routing, does that matter? some of the wires cross each other. My stock wire looms broke. If I have bad piston rings and lacking compression in a few cylinders, would it better to return the gaps and timing to stock?
 

·
Registered
Joined
·
1,240 Posts
Discussion Starter #8
Okay, it was a cooler last night like in the 60's and guess what? The Bronco had a good amount a power. There are no codes whatsoever. What would cause the engine to run so bad on a hot day? Its almost like a 30% reduction in power.
Thanks-
 

·
Registered
Joined
·
710 Posts
Maybe the fella above is thinking what I'm thinking... It could be your fan clutch is locking up. That fan will rob quite a bit of power from you when it completely locks down. Run it for a bit, make sure it's performing weakly like you say, then immediately get out (turn off bronco first) and spin your fan by hand. It should turn freely, if it's hot it should be stiff, but if it is very very stiff and the truck isn't very hot then sounds like a fan clutch.

That's the only thing I can think of that would do that, aside from possibly a bad gasket somewhere and when it gets warmer the gap opens up more...
 

·
Premium Member
Joined
·
10,000 Posts
Definately "pull codes" FIRST and see what's indicated making your diagnosis much easier...instead of guessing....

Usually distributor caps have a molded slot or grove for the distributor so it only goes on one way, my MSD is designed like that, what Mfg are you using?

You can bend the "cap clamps" so they snap tighter, bend the "curve' a bit more.

Make sure the plug wires are adequately "spaced" apart so they don't "cross over arc....robbing you of power....

I would FREE TEST the ignition module which ever type you have ie: TFI = thick film integrated located directly on the side of the distributor or remote located igniton module....loss of power there could mean it's either failing or on it's way out..

Insuring the plug wires "click" or "snap" onto the plug is important otherwise you get a miss fire, robbing power...use a little dielectric tune up grease in there so they will slide on and off better...you'd be surprised at what extreme heat does to rubber boot ends...

I'd start back at orignal plug gap and timing and see how that works, pulling codes and once you feel you have all these issues in hand then go back to the plug/timing upgrade and see how it runs again with the change ....


Good Luck ~ :thumbup
 

·
Registered
Joined
·
1,240 Posts
Discussion Starter #13
There are no codes. It seems like its only hot days the engine looses power, which leads me back to the timing being too far advanced. I think the crossed plug wires could be causing it. I think the cat might be getting more and more plugged also. The cap is a motorcraft cap, its only loose up and down not side to side. It seems like there should be 4 clamps to hold it down, but there are only two. How do you test the ignition module? Mine is on the distributor.
Thanks again-
 

·
Premium Member
Joined
·
10,000 Posts
It's hard to think that there were no codes for both KOEO and KOER.......and you got a PASS, #11 on both.....?


Pull the ignition module and ignition coil off the vehicle and take it to an Autozone type store and they'll test it for FREE, R & R if necessary....AND figure out why that distributor doesn't fit correctly......?

Crossed plug wires would create poor performance like a miss unless all the wires are really out of sequence which I doubt......if the timing is eithe retarded or advanced too much it might make the vehicle run hot......so set it back to the stock OEM designation....and go from there......make sure the Thermostat is function as well as a matter of routine maintenance.....hot engine for any reason don't run well and can add to component failure........

I'd still be inclined to think it's the igntion module or possibily the coil...., cold start fine but when things warm up it fails, stalls and cranks over but won't fire up.......very common....

Good Luck ~ :thumbup
 

·
Registered
Joined
·
1,240 Posts
Discussion Starter #18
I think its either crossed plug wires or the spark plug gap combined with the timing and probably dealing with a cat on its way to getting plugged. As well as maybe some spark plugs boots didn't get fully on. Truck ran pretty well today in the hot weather, got fair gas mileage, but still not as much power as a cool day. I lost power after I gapped out the spark plugs. So, its either how I put back the wires or it can't handle the gap. The coil is brand new. So, is the cap, felt a slight power increase after adding those two. Before I did the gaps, I did the timing. Gained pretty good gains in mileage and power in the cold weather. But, towed a heavy load in some hot weather and it didn't do so well. Lost power and started pinging pretty bad. But, when I got rid of the load, it was fine. The engine cools normally, just replaced the thermostat with a 195 degree. The temperature needle stays right in the middle of the normal, if not more on the cool side.
Thanks-
 

·
Premium Member
Joined
·
10,000 Posts
Get some "dielectric tune up grease for those spark plug boot ends to get them on easier, my #2 is difficult to get at due to the smog tube running along side the engine from the pump along to the back air bypass valve making it hard to "snap" on, can't get proper leverage in that spot if you now what I mean.....lol lol

Make sure the "temp guage sending unit" is functioning correctly, located up front threaded into the lower intake manifold....they can give off flase readings, the Brass style is the best and only costs around $10.00 out the door.....

Maybe it's also time to service the tranny with a filter/gasket kit and fluid......

Good Luck ~ :thumbup
 

·
Registered
Joined
·
1,240 Posts
Discussion Starter #20
The Transmission was acting fine when towing. It just got new filter and fluid anyhow. It was the engine bogging down under the extra load and it was pinging pretty bad and got 5 mpg or lower towing. This was with the .042 spark gap and 12.5 degree timing. When not towing something, it doesn't usually ping even at 13.5 degrees, although it does a little more on a hot day. Does anybody that has done the six litre tuneup and timing bump have any experience with towing with it?
 
1 - 20 of 20 Posts
Top