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89 bronco II

Posted: Thu Apr 27, 2017 3:21 pm
by Frustrated+
I have a bronco that will start off running like a champ for about 4 miles then even though foot still on gas peddle it starts to loose power backing off from 60mph to about 35, no matter how floored I have it, it will not increase in speed. New ignition module, distributer, cap and rotor wires, plugs, throttle body sensor, map sensor, heat sensor, air flow sensor, doesn't have an Egr valve, new gas tank, fuel pump, fuel filter, relays(fuel pump can't think of one next to it). Oil gauge constantly goes from high to low while driving, can an oil pump cause this problem? About 1/2 year put in an additive to clean fuel injectors checked oil about a month later it came out thicker than molasses, quickly changed it but this slowing problem was already present. Can anyone tell me what's up with her??? Cylinders all check out as being functional, fuel pressure is up to par. HELP I love my Bronco II.

Re: 89 bronco II

Posted: Wed May 03, 2017 7:08 pm
by tekatlarge
Have you checked the computer codes? That would be a first start. What did you actually measure for a fuel pressure? Has this rig sat much?

get back to us with the answers and maybe we can fix you up. :cool:

Re: 89 bronco II

Posted: Thu May 04, 2017 6:09 am
by Frustrated+
The only codes that came up was Ego and I thought that meant Egr but found out I don't have an Egr valve. For fuel pressure it started at 40 and slowly went down to about 35 and held.

Re: 89 bronco II

Posted: Thu May 04, 2017 6:11 am
by Frustrated+
This is my daily driver , so she doesn't sit all that much, even now for the last 3 years have had a job only 12 mi away so as not to tax her. I get home and stay till next day.

Re: 89 bronco II

Posted: Thu May 04, 2017 5:08 pm
by tekatlarge
That fuel pressure is actually low from what I normally see IIRC it is supposed to be 40. and steady. When you unplug the vacuum line that goes to the fuel pressure regulator what change if any do you see? It should be rock steady. BTW look at the end of the vacuum line where it attaches to the regulator and make sure no fuel is present, If you have fuel at the vacuum port the regulator is gone.
If you happen to have a Vacuum pump hand held you can attach it to the fuel pressure regulator and put a vacuum on the regulator and watch to see if fuel pressure varies when you change the vacuum.

To me my gut feeling is you have a fuel delivery problem You said you replaced the fuel filter. There is another little device in the fuel system called a fuel accumulator. This device looks like a fuel filter on the line but it it Not. It is basically a little reservoir that holds fuel so the EFI won't starve out of fuel if your pump in the tank should be momentarily un ported it keeps fuel fed to the injectors to allow the pump to recover. It is a short amount of time it takes but it is important. The older ones you could actually take apart and they had a filter screen that would get mucked up but the newer ones I see now are sealed units. If this fails to allow enough fuel through it will cause the vehicle to lose power and the fuel pressure will drop and not be getting enough pressure the injectors need.

So look underneath I have seen them along the frame underneath disconnect it and check to see it is not blocked. While you are at it blow some air back through the fuel line to the tank to make sure it is not blocked.
One last check and that the fuel cap allows air into but not out of the tank.

Good luck.. :cool:

Re: 89 bronco II

Posted: Sun May 07, 2017 4:00 pm
by drofman
Does it sound like a vacuum cleaner when you drive it? Plugged exhaust maybe? I like where Tek is going, maybe drive it with fuel pressure gauge on it to rule that out.

Re: 89 bronco II

Posted: Thu May 11, 2017 1:21 pm
by tekatlarge
Hey Drof whats up? Been doing anything fun? I haven't done a lot lately. Still working on my TCoupe project. It is coming along slow but it is moving slowly forward. It is going to be dealt a big blow come mid June. I have to take a little hospital time and have my right shoulder re-placed. It really sucks getting old! There is a 3 to 4 month plus recovery time. Thank god I am proficient shooting left handed. I I can entertain myself shootin all them varmints in the woods here or any other varmit that darkens the doorway.

I still keep my eye out for a BII to stuff my 2.9 in but so far haven't found "The One" There is though, a Exploder Sport just down the back trail from the homestead a few. I might stop by one day and see what his plan for it.. :cool:

Re: 89 bronco II

Posted: Fri May 12, 2017 9:54 pm
by drofman
Hey Tek, Yep did a 5 day on the trail run in Death Valley the 1st week in April. Started in Beatty, NV and ended up at Lone Pine, CA. Took the F150 but missed the B2 a lot. Next year we are going to do the Mojave Road again. Ya my Dad used to say getting old is not for sissy's. I had my right shoulder rebuilt 4 years ago and so far all my other pieces are doing fine. Be safe and well my friend.

Re: 89 bronco II

Posted: Wed Jun 07, 2017 8:34 pm
by tekatlarge
Yes gettin old is not for the faint of heart..I just finished 7 days post op from a complete shoulder replacement! No fun but it gets better each day.. All these pills, 1 for up, 1 for Down, 1 for Left, 1 for Right, and a hand full more just to feel right...I like the little ones.

Of here come the nurses with butterfly nets. :cool:

Re: 89 bronco II

Posted: Fri Dec 15, 2017 7:12 pm
by 88broncoboy+1
About your b2 all of a sudden going crazy on you, I have an 88 b2 with a v6 I bought for a project car/daily driver. Without me knowing it my wife had my son put some Rossignol engine cleaner treatment in my oil. The 18 year old kid in the part store told her she should use it when all she wanted to get was injector cleaner ,needlless to say this stuff just tore loose everything inside my engine, just like you are describing, it had broken down all the internal seals that lubricants create over time,my power disappeared, lifters were chattering, I'm sure my rings deseated, my engine really sounded like it was going to blow up. After a week ,she casually stated what she had done, she couldn't imagine why it was acting up, and said her car was running great. She just happen to have her oil changed two days after she put it in her car, a 2 year old cadillac, I exploded, over the week I checked my fluids and all were ok, I immediately changed and flushed my oil 3 times, you should have everything in the filter and the oil,. I the put a heavier oil for 2 days then drained and went back to my 10w30, my motor is running great. I, After 42 years of being married to this woman i could write a best selling novel about all the crazy things my wife has done to all our vehicles. because she listens to people who swear they know what their talking about, try doing what I did, 88broncboy