460 backfire

[jimmyz]

I have a 1998 HR Endevour with a 460 ford EFI engine. I have put 30000 miles on engine with out a bit of a problem. It uses no oil between oil changes and uses gas at about the normal rate for a 460. I don't think it has any bearing on my problem but I installed a complete Banks system on the engine about a year ago. About six or seven months ago the engine started to backfire now and then. It always happens within ten to fifteen miles after I set out and it does it ones and that is it for the rest of the trip. I can drive all day for as many miles as possible that day and it will not do it again. The nexy day it may or may not do it but if it does it will be in the first twenty miles and if it does not do it in the first twenty miles then it is not going to do it. I have had times where it will go for two or three weeks with no backfire and then do it three days in a row. When it does backfire it is one hell of a bang and it sure gets people to look my way. So far the exhaust system has been able to take the blast but I don't know how much it can take. I know it is hard to trouble shoot a problem like this but maybe someone has had the same thing happen to there 460. Thanks in advance for any help.

[mpaton]

Sounds like extra air is getting into the exhaust system. This could be from the air injection system, or a leak in the Banks system which closes up as it heats up. Does Banks call for a retighten of all fasteners after some time in service? Probably worth doing that.

Also if you investigate if you have any codes stored in the ECU. Remember that you have an OBD1 system, so you may have codes stored without getting a Check Engine light. The ECU is capable of checking the air injection (Thermactor) system.

[subford]

A lot of posters have reported this after installing the Banks system.
It is a known common problem but I do not remember what they said that Banks told the to do to fix it.

[Topflite51]

Glad to see that I am not the only one suffering from CRS syndrome. I too recall reading several different posts along these lines all having something to do with Banks. I suggest a call to Banks and see if there isn't an easy fix. Just can't remember what it was about.

[justimagination]

Quote:

Originally Posted by mpaton Sounds like extra air is getting into the exhaust system. This could be from the air injection system, or a leak in the Banks system which closes up as it heats up. Does Banks call for a retighten of all fasteners after some time in service? Probably worth doing that. Also if you investigate if you have any codes stored in the ECU. Remember that you have an OBD1 system, so you may have codes stored without getting a Check Engine light. The ECU is capable of checking the air injection (Thermactor) system.

........Times 2, I would check the header flange where it mounts to cylinder heads and make sure the gasket is not blown out or leaking. Good luck, let us know your fix.
David G.

[JohnRR]

Results from a quick search here for banks backfiring maybe it'll give you some interesting reading on the subject.

[jimmyz]

Well thanks for the heads up on the banks system. I kind of thought it could be that the banks system was part of the problem but I had never heard any other complaints the same as mine. Tomorrow I will put my scan tool on and check for codes as well as try checking all the bolts on the manifolds. As for gaskets Banks does not use manifold gaskets on the exhaust because they say there manifolds are machined so well that they do not need them. I must say that when I first installed them they where very well sealed and showed no signs of leaking. Of course that was 7000 miles ago so I will check again to make sure there is no signs of leaks now.
I have a smoke syatem for checking evap systems so tomorrow I will put it in the exhust pipe and see if I can see any smoke comming out of the pipe anywhere. Thanks again for the info and I will post what I find out

[JohnRR]

Ryder truck rental for the years the 460 were in the fleet had a policy when repairs were done no manifold gaskets were re install at time of repair and they worked perfectly fine without them.