Thread: Backfire and Insulating Tape

My 3.5 V8 backfired today and would not run afterwards.

After a quick check I found a joint downstream of the MAF and before the Inlet Plenum that had been sealed with Electrical Insulating tape.

I'm guessing that the join had started to leak air, hence the backfire. The Electrical tape was further damaged by the backfire and it was clearly allowing a lot of air to leak in after the MAF.

So I have temporarily fixed the problem by using, you guessed it, electrical insulating tape. The motor now starts and runs fine.

But, what should the connection between the MAF and the Inlet Plenum look like?

Here are a couple of pictures of mine. You can see the green tape I put on today.

Paul

What you have wrapped the tape around is a device for protecting the flapper from the effects of a backfire. There should be a swinging trapdoor up against the flapper end of the device. Where your tape is there should be a simple rubber ring covering the holes, that ring expands and lets a backfire escape without destroying the flapper. I suppose it perished and split sometime before you purchased the vehicle. The rubber may be available as a spare from a LPG wholesaler or you could try to make a new ring out of something like wheelbarrow inner tube. The tape will not stay air tight if it gets hot and the glue softens and the tape starts to unravel. Don't be tempted to make the area too strong, eg by using a wide hose clamp instead. You'll just transfer the damage elsewhere.