HELP PLEASE!!!! So I had purchased a 1988 ford bronco 2 xlt with a 2.9 liter cologne motor replaced fuel filter twice replaced spark plugs and wires, air filter, and oil filter. Ran fine up until I was riding down to my buddies house and it just wouldn’t go past 60-65 it eventually wouldn’t go past 55 then 50 then 45 and so on it got slower and slower when I press on accelerator and eventually won’t go past like 5-10 mph when this is happening it just slows down as if I’m pressing on breaks almost and she just bogs right down It seems to drive alright in very cold temps and run horrible and bog down on me on nice hot days like 50 degrees and up I also checked the fuel pressure and it read 29-30 psi which is okay when in idle I taped it to windshield took her for a spin until she started bogging down again and wouldn’t let me go past a certain speed and the fuel pressure gauge was reading 0 what do you think it could be with it being a on and off problem I also been real real easy on pressing the accelerator I’m talking I’ll press on it wait till it gets to 35 then press on it a little more and get her up to 45-50 but I’m scared to go past that but I need it to get to school and work and back any ideas what it could be any help would be very much appreciated!!!
So just to give y’all a little update I replaced both fuel pumps idk how I managed to do so by myself but I did and she hasn’t been bogging out on me since so that problem is fixed…..hopefully lol thank you for all the advice/tips I greatly appreciate it😀
Replace the fuel filter and then pressure test the fuel pump. It could be either clogged fuel filter and/or a weak pump.
I’ve changed the fuel filter twice and it still had been doing the same thing I checked fuel pressure through the stratter valve and it read 0 when it was bogging out
It also almost always starts up sometimes you got to turn the key twice but she’ll always start up I thought if it was a bad fuel pump the truck would have a extremely difficult time starting because even when it’s bogging out horrible I can shut it off and turn it right back on
Pressure test the fuel pump. These are the signs of bad fuel pump.
I believe that vehicle has two fuel pumps. A low pressure pump in the gas tank and a high pressure pump mounted on the frame. Pray it's a problem with the external pump.
It only does this when running for a little bit and especially on hot days and yes the bronco 2s have 2 fuel pumps I can try the external one and if I need to drop the tank then I will I’m also gonna try the tfi module and fuel pump relay and see if that does anything I replaced the map sensor and it did nothing. How do I pressure test the fuel pump all I know is how to just pressure test through the stratter valve
My guess is the Schrader valve test you've done is really the only way unless there's another valve between the two pumps. There is also an accumulator or reservoir between the pumps. If it were me, before going to a lot of trouble, I would replace the external pump first and cross my fingers. Rock Auto has them for $26.
I would make sure your exhaust system is solid. Almost sounds like a collapsed catalytic or muffler causing huge back pressure.
Could be a dirty fuel tank
When ur having this problem if u let up on the accelerator does it perk up?
I had originally thought it was the cat and was getting ready to replace it but there was good air flow coming out of exhaust it didn’t seem clogged or anything like i said she drives fine when it’s cold out and I also tested to see if there was water in gas tank but the pumped some out and it looked fine if it was fuel injectors this problem would be consistent right? Because it only happens on warmer days and when it is running for a while but no when it bogs out around 50 if I press on the accelerator too much it bogs down as if I’m pressing in the breaks and rpm’s go down but once I let off accelerator it just slows down as if I’m not pressing anything like it’s supposed to but when this happens there’s a certain sweet spot I have to hold it down because if I press too much it bogs out
I think I would start by draining the tank
if the filters etc. have been changed and vetted theres not much left
Yea that and I asked just put a new tfi module on and it didn’t really do nothing so I’m gonna try replacing fuel pumps next hopefully it’s just the external one but I’m eventually drop the tank anyways
You can drain the tank w/o dropping it
HF has a manual transfer pump that works very well
I used it to drain mine
So I can drain it so I can put on this external pump? And I got both external and internal for the hell of it. Any clue what it could be if it’s not the two pumps also my truck usually takes like 2-3 sometimes even 4 to cranks to turn on it will crank but not turn on do you think this may be linked to the acceleration problem
I drained my frontier tank and when i removed it there was almost no gas in the tank
The manual pump works surprisingly well
Imo I think the first step is drain then add some fresh fuel
See if that fixes the problem
If not then external pump next (test etc)
If not then onto the internal pump You may have to drop the tank (my xterra allows for pump replacement by removing the back seat