Backfiring help

[ducttape]

Can anyone offer some advice:

Series III ex-MOD with 2.25 engine. I don't know the year because I am sure the vin is incorrect. VIN points to a '67 Series II but there is nothing Series II about this.

During warm up I get rather strong exhaust smells all around. When the choke is pushed in the smells dissipate, but the truck tends to back fire. I know it happens when I ease off the gas. It has happened at 'full throttle' on the hiway. Not sure of other times.

All I can say is it scares the hell out of me because I don't expect it and it's loud as a canon.

Can anyone venture a guess as to the cause and remedy?

TIA
David

[east high]

Is your timing properly set?

[ducttape]

I dunno, but I would assume so. I spent a fortune at Vinnies at Rover Specialist in Dumont after I got it, getting a 'tune up' etc.

This all developed several weeks after that, so I am assuming it is relatively new and unrelated to anything maintenance related. I could be wrong of course.

[greenmeanie]

Check you exhaust joints are tight and the manifold mounting. An air leak will have this effect.

I once had to drive a couple of hundred miles home with an exhaust that had come apart at the center joint on an 88. It was suprisingly effective at getting people out the way as she sounded like a Sherman tank when I was on the throttle and let rip like a machine gun when I let off.

Great fun but I was deaf for about a week afterwards

Cheers
Gregor

[ducttape]

Speak up please, I am having problems hearing lately...

Just get in there with a wrentch and tighten, or am I looking for broken gaskets, etc etc?

Thx

[jp-]

You are looking for loose bolts/nuts and possibly leaking/broken gaskets. First, check the timing as mentioned. Then take out the plugs and put about a capful of ATF in each cylinder. Put the plugs back in and have someone else start the truck, while you watch around the manifold. If you see smoke, you have a leak. If the timing is ok and the manifolds are tight, suspect carb problems.

[Bostonian1976]

when my distributor's bolt came loose and the distributor spun itself freely, the drive home yielded tons of backfires and a few fireballs from the exhaust pipe (this was at night so imagine the effect). def. check your timing

[I Leak Oil]

Could be the timing, points gap,vacuum leak, carb problem or poorly adjusted carb, valves out of adjustment.....I'm sure I missed something but just start checking things off and you'll get it resolved.
Jason T.

[jp-]

Could be the timing, points gap,vacuum leak, carb problem or poorly adjusted carb, valves out of adjustment.....I'm sure I missed something but just start checking things off and you'll get it resolved.
Jason T.

Points gap, often overlooked, good point.

[Jeff Aronson]

The exhaust is the most likely culprit; unburned fuel makes the racket. Look for loose bolts along the length of the exhaust.

Backfires usually start somewhere else, though. If you're running rich [carb adjustment, vacuum leak, timing retarded, bad points, poor valve adjustment], the gas mixture will explode in the exhaust and cause quite a backfire.

I also had one doozer happen when my rubber fuel line into the carb collapsed and caused a clogged line on the interstate. The resulting backfire as the car had nothing to burn was quite exciting!!! So make certain you don't have black goo in your carb float chamber.

Best wishes,

Jeff

[Les Parker]

David,

Does this have a Ducellier distributor fitted?
If so, try disconnecting the vacuum advance line from the carb.
This style of dist. is reknowned for the vac. advance unit failing, causing the symptoms you describe.
Solution ??
Fit a new distributor PLE143 for $129.00

[ducttape]

Hmm, in other words, one of my coming weekends is going to be spent under a hood, cold, and guessing

Thank you all. Probably next week. And of course, I will try to keep everyone posted on the problem!

[Bostonian1976]

Hmm, in other words, one of my coming weekends is going to be spent under a hood, cold, and guessing

I believe you just described life in general with a Series Rover

the great part of these trucks is that you learn a lot about how an engine works and what to look for next time..