2.9 Backfiring

[myprobe1991]

I am having an issue with my truck. It runs but it seems to have a miss. I R&R and the plugs and wires and tried it out. Well the engine don't run any smoother but I figured it needed it anyways. When I pulled the plugs, I found the #1 plug was fouled real good while all the others looked clean. Pulled codes and it showed 14, when I looked it up it told me the ICM was getting intermittent readings. R&R the ICM and it seemed to work really well for oh about 2 days, now when I drive it not only does it lose power but I can hear it popping through the exhaust. I assumed its the timing simply because that is what I have always been lead to when a vehicle backfires. The smell of fuel gets real bad and then all of a sudden, it runs good again. I have gotten so frustrated up to this point, I am looking at just doing a complete engine swap and being done with it. I REALLY LOVE MY TRUCK! PLease help if you can. Oh a mechanic friend of mine said it could be the distributor

 

[WNYBroncoBill]

If it were mine, I would look further before I did an engine swap. Usually these problems are a simple "fix". Find someone who knows the 2.9 before anything drastic.

I was ready to give up on my 88 XL, but I installed Alabama Cylinder Heads[/last week and it runs great! These are upgraded heads with large rocker '"bosses".

These are German Ford engines, designed to last a long time. Problems are after Ford North America modified them (their heads, etc.)

Good luck,

Bill

 

[FutureX]

did u check/replace the 02 sensor

 

[wallen308]

this may be a related question......86 Ford Bronco ll, 2.9.......if you don't let it run at least 3 minutes after cranking, even when its hot, somewhere down the road usually within about 20 miles, it will suddenly start cutting out, as if its a vehicle with an old manual choke and you pulled the choke out. Then suddenly it starts to run perfectly again. Any suggestions?

 

[410Fortune]

86 BII had two fuel pumps, it sounds like the boost pump (in the tank) is going out

 

[FutureX]

mine does that every now and then, but came to conclusion it was because i was in a hurry and wasnt giving the auto choke time to engage ... u can tell when it engages as of the idle difference... from real high to normal.. takes about 3 - 4 mins to warm up.. i always let my rig sitt at least 5mins before i start my day....

 

[WNYBroncoBill]

I have read that the transfer pump in the tank is not required until the tank gets below 1/2 tank, then gravity will not feed the fuel line to the boost pump under the driver's floor/frame. Try a full tank?

As far as the auto choke, mine is a 1988 FI, so no choke, but if I had a carbureted one, I would make sure the heat muffs, intake tubing and and flex. tubing connecting them are in good order.

People tend to discard these items - I believe they are there for a good reason. Perhaps a Ford "Better Idea" from the 1980's?

Bill

 

[wallen308]

this critter does it even after you've driven for an hour, and stopped for a minute at a store. then when you crank it back up, you got to let it sit at least 3 minutes. it idles up and down

by the way, its a 1988 2.9......I had the year model wrong in the first posting.

thanks, everybody

 

[410Fortune]

86-90 are all the same for the most part

no choke on these suckers, they are EFI

in tank boost pump is required for uphill climbs, if you park on a hill, or if you are at WOT for an extended period of time

fuel pump relay is first suspect then a weak or non working in tank pump