95 bronco confused

[mawhitmore]

ok so the bronco came in missing dist cap and all plug wires. the engine is 5.0 and the mfg date 04/95. as far as i can tell it doesnt look like any major engine work has been done. so i went and purchased a set of plug wires and figured might as well do spark plugs too. now it was my understanding that the 1995 5.0 engine's firing order is 1-3-7-2-6-5-4-8. the problem is it wont run with this firing order. but if i switch the order to 1-5-4-2-6-3-7-8 it will start right up and run but with a rough idle. any thoughts?

 

[Rons beast]

I have encountered this twice. Once the timing was so far off the engine was running backwards. If I hadn't seen it myself I would not believe it.

The other time I found a V6 distributer in a V8 engine, with a V8 cap installed.

The second timing order you quoted is similar to a V6 order, and the pulses would cause random misses.

Another possibility is a timing chain that jumped?

anyone else? I'm intrigued?

 

[Rons beast]

Update.... 1-5-4-2-6-3-7-8 is the firing order for 255,302, and 460 V8s from 1993 and earlier. Maybe someone tried to "Frankenstein" your engine? With an older cam and such.

I don't know if that is even possible, but hey someone is always gonna try something, that's how I found the crazy thingd I had before.

Good Luck.

 

[mawhitmore]

Update.... 1-5-4-2-6-3-7-8 is the firing order for 255,302, and 460 V8s from 1993 and earlier. Maybe someone tried to "Frankenstein" your engine? With an older cam and such.

I don't know if that is even possible, but hey someone is always gonna try something, that's how I found the crazy thingd I had before.

Good Luck.

thanks for thoughts. man ive been pulling my hair out over this. so from here i guess i will round up a dist. from a 95 5.0 engine and that might do the trick? any suggestions on the route to solving this?

 

[Rons beast]

Hook up a timing light to no.1 and watch the marks. If it looks like they jump around the balancer then the distributer is probably the culprit.

If the marks stay constant and normal, take off the valve covers, and disconnect the coil wire. turn the engine over by hand till both valves on #1 are closed, and the rotor is at #1 wire position. then turn the engine to the next firing position, (rotor moving counter clockwise) and find what cylinder has both valves closed. should be #3 or #5, that will tell you what firing order the engine is cammed for.

If it is the old firing order, some more research is needed to determine if it is viable for your engine. It probably is not with EFI, unless the fuel timing is changed too.

 

[mawhitmore]

Hook up a timing light to no.1 and watch the marks. If it looks like they jump around the balancer then the distributer is probably the culprit.

If the marks stay constant and normal, take off the valve covers, and disconnect the coil wire. turn the engine over by hand till both valves on #1 are closed, and the rotor is at #1 wire position. then turn the engine to the next firing position, (rotor moving counter clockwise) and find what cylinder has both valves closed. should be #3 or #5, that will tell you what firing order the engine is cammed for.

If it is the old firing order, some more research is needed to determine if it is viable for your engine. It probably is not with EFI, unless the fuel timing is changed too.

hey thanks for your help. i will try that today and see what i find out. thanks again

 

[BroncoJoe19]

This firing order 1-5-4-2-6-3-7-8 can cause an induction missfire. Make sure that your cyl 7 and 8 wires are separated.

miesk5 has more information on his broncolinks.com site on this topic.

 

[Rons beast]

So what was the result of all this speculation?