back fire/engine miss

[jia]

I replaced the throttle body on my '97, V8 - 5 liter Explorer because the old one was sticking.
Now I'm experiencing a back fire/engine miss problem. I really only exerience the problem when
I'm accelerating full throttle from a stop, low speed or up a hill.
I've had it to a Ford service dept to check all the codes and after replacing a "bad" pressure
feedback sensor, the problem is still there.
Any info/help/words of wisdom would be much appreciated.
jia

 

[mrboyle]

Sounds like you have a lean miss. Check for a vacuum leak around the throttle body, or a hole on the intake tube (they like to rip when you are attempting to remove them).

 

[jia]

Thanks for the suggestions; however, they didn't seem to help. I even put small hose clamps on the vacuum tube coming off of the throttle body.
Perhaps some more info might be helpful. I've noticed that the problem really only occurs when I'm doing a full throttle acceleration from lower speeds (about 30-40 mph)like when merging with traffic from an on-ramp. I usually get a pop, pop, pop or sometimes a single pop right before the transmission shifts out of "passing" gear. I don't get the backfire (popping sound) when I'm at highway speeds (60-70 mph) and I go to full throttle.
Again, thanks for your suggestions - anymore you
might have would be greatly appreciated.

 

[Chris Jella']

Hey jia,
I'm having the exact same problem as you are except mine is a 4.0L OHV engine. Mine pops when floored sometimes just before and always just after it shifts into second gear. If anyone can help on this I'd appreciate it. I've replaced everything shy of the ICM on mine.
CJ

 

[jia]

Not sure if anyone is interested in this or experiencing the same problem I did - not many replies to this thread - but I think I found the problem. I say think because I got rid of my 97 to buy an 02 and didn't bother to invest the time and money to try my fix.
Anyhow, I located a small exhaust leak in the driver's side exhaust manifold. It was very small but there. I think if I had replaced the exhaust manifold that would have probably fixed the situation.