I just bought my 89 B2 w/auto trans 152k miles. I believe the truck was sitting for a year or two. It was backfiring at idle after warming up and had a really bad hesitation problem...I changed the wires,cap and rotor and that stopped the backfiring and helped the hesitation a bit but while driving it seems to lose power from half throttle on.

I was going to check the timing for the hesitation problem but I cant seem to find the timing marks on the crank pully...I heard that they may be visible from under the truck...I have not had time to check that though...

Also, since I have started driving it a valve tap started that comes and goes. When the tap it there it is constant, even when accelerating and after it warms up. The tap was not there when I first got the truck and since I started driving it and replaced the cap, rotor and wires..it started. I am not sure if that can be caused by a timing problem or maybe the valves need to be adjusted...

I also did come exhaust work and noticed that there is a small hole on the pipe before the cat and after the 02 sensor that looks to be factory( it is not rotted or rusted) and it obviously leaks...Is there a pipe or sensor that goes there??? Can that be causing some hesitation??

Any help would be greatly appreciated. You guys have been great with all of my questions so far on my project. Thanks Again. Have a great New Year!

 

b2's are notorius for lifters if it's a constant tapping noise do you hear it when you are driving ? or when your idleing ?
or both? as for your exhuast question there shouldn't be a hole right behind your o2 sensor nothing should be there i saw your post on trs trying to get as many helpful advice as possible that goods

 

The tapping happens all the time...Is there any way to fix that?? Thanks for the help.

 

Thanks for the info

 

some people try putting thicker oil in their b2
like 4 bottles of what ever grade you normally use
and one bottle of sae40 . but the only way to really clear the problem
is to change the lifters and when you do clean the opening were the lifters are real good .

 

The exhaust leak could cause a false O2 reading which is causing your power problem. If thats not it check the timing, you should be able to see the marks from the top passengers side of the crank. Also test the fuel pressure and pull the codes.

 

Monty has done the lifter thing, with the free floating or w/e.. the ticking is gone for him, so it can be done.

 

Thanks for your replys...Happy New Year;

I am in the process of finding an adapter for my fuel pressure test kit so I can test the fuel pressure.

I patched up the hole near the O2 sensor and it did not stop the hesitation.

I replaced the TPS....NO HELP!

I noticed that after driving for a while when I stopped, put it in park and put the pedal to the floor it boggs down. I let it cool down for a while, started it and put the pedal to the floor with it in park and it did not bog down but it still hesitated when I drove it(from 1/4 throttle on..).

Also, I unscrewed the O2 sensor and just let it hang outside the exhaust and I had no hesitation( Obviously I had a check engine light).

I am totally going crazy with this truck...I do not know where to go from here.

Any help would be appreciated...

 

The ECU would detect the faulty reading from the O2 hanging in the air and disregard the reading. Try clearing the codes, since you set one, drive it for a while and then pull the codes while your working on the fuel pressure numbbers.

 

Fuel pressure is at about 38psi. and there is no fuel in the vaccum hose of the FPR.

I would reset the ecu codes but I do not know how to.

I checked the spark plug wires with the diagram in my chilton manual and they are correct.

I put a new O2 sensor in and that did not help.

It seems that the truck is fine when I first drive it but when it warms up it just dies from about 1/4 throttle on...The RPM's go from 2000 down and once in a while it pops when I am stepping on the gas which sounds like it is coming from the intake because when i hit the throttle manually the cover on the intake pops up. It boggs down even if the truck is parked and I hit the throttle manually...and once again when it cools down for a while it is fine until it warms up again.

I am not sure where to go from here...I am thinking maybe the ignition coil??

You guys have been geat with your tips...Thanks Again.

 

Unplug the battery for 30-60 seconds

 

I had the exact same symptoms with by 2.9L 1989 Bronco II. It finally showed its hand when the fuel pump quit completely (in my driveway). I replaced the pump and ALL the hesitation problems went away. I don't think fuel pressure without loading the engine tells the whole story. Incidentally, it was very easy to change the pump by cutting a 10 x 10 hole in the floor. Just use a nibbler or shears to keep from cutting into the tank. Drill holes at the corners of your cutout and cut straight lines. Good luck.

 

so how is the update any change with the truck ? still need more help?