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Discussion Starter · #1 ·
I live on a steap hill and when i put the throttle down it just doesnt have any power. This is what I have done. New plugs , new wires , new cap and rotor ,
new fuel pressure regulator ,new throttle position sensor it's reading .92 at idle and I have cleaned the throttle body and iac. The only code i'm getting is code 33 egr valve opening not detected. I have cheaked it and all shows the egr is good,i have checked the vacuum and the elec and it shows good.
MY QUESTION IS,if for some reason it is bad can a egr valve drian it of power under WOT going up a hill?
Thanks :banghead
 

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walton34 said:
I live on a steap hill and when i put the throttle down it just doesnt have any power.
<snip>
MY QUESTION IS,if for some reason it is bad can a egr valve drian it of power under WOT going up a hill?
Thanks :banghead
Is the code 33 egr valve opening not detected due to your testing or is it real? If real then either the EGR valve is bad, not receiving any vacuum to open it, or the sensor is bad. Unplug the vacuum line and see if it increases when you rev the motor (needs to be up to temp). With engine idling apply vacuum to the EGR. RPM should drop and engine should start stumbling, maybe even die. If you don't have a vacuum pump, just suck on the line should be enough open it a little.

Yes. Some things that could cause power loss due to EGR valve are valve stuck open, leaking when valve closed, open valve when it shouldn't be. But closed EGR valve is what you want when demanding power.

To determine if EGR valve is the cause of power loss. Take it off and make sure the valve closes all the way. Put it back on but leave the vacuum line disconnected and plugged. Go pull your steep hill and see if it's better. A code may get set due to this but no biggie, just depends on how far you drive it without EGR connected.

What's the condition of your exhaust system? Especially the CAT(s). Restricted exhaust system can also result in loss of power.

Did you check the timing? Remember to remove the SPOUT connector when checking/setting timing.

Air cleaner?
 
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Discussion Starter · #3 ·
like my first post said, i checked the egr valve and and it checks good, yes i checked the vacuum with a pump yes it getting vaccuum ,yes it holds vacuum. My Question is can a bad egr valve cause it to lose power under wot and only wot,it has plenty of power at all other times.It didnt change pulling the hill,that was a good idea pluging the vac line I hadnt thought of that
Thank You
 

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walton34 said:
like my first post said, i checked the egr valve and and it checks good, yes i checked the vacuum with a pump yes it getting vaccuum ,yes it holds vacuum. My Question is can a bad egr valve cause it to lose power under wot and only wot,it has plenty of power at all other times.It didnt change pulling the hill,that was a good idea pluging the vac line I hadnt thought of that
Thank You
Well if the EGR valve is known to be closed and not leaking then it's not the EGR valve causing the WOT power loss. Look elsewhere like, exhaust flow restriction, fuel flow restriction. Just because you have good fuel pressure at idle and lower loads doesn't mean there's enough flow capacity to maintain it at higher flow rate when under load. I believe that year has two fuel pumps, an in tank pump and a pressure pump mounted on the frame rail. Also could be fuel filter.
 
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Discussion Starter · #5 ·
no mine only has the pump in the tank, i have checked the pressure it's 35 at idle and about 45 with the vacuum line disconnected, new fuel filter at time of the pressure regulator. i just ran codes again and i'm getting another code now that i wasnt. when i ran the koer it's showing code 45 there are two code 45 and why would it just now show up? i checked it this morning and it wasnt there.
Thanks
 

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walton34 said:
no mine only has the pump in the tank, i have checked the pressure it's 35 at idle and about 45 with the vacuum line disconnected, new fuel filter at time of the pressure regulator. i just ran codes again and i'm getting another code now that i wasnt. when i ran the koer it's showing code 45 there are two code 45 and why would it just now show up? i checked it this morning and it wasnt there.
Thanks
What is a code 45? Due to driving with EGR disconnected maybe?

You need to know if the fuel pressure is good under heavy load. If you can hook up a fuel pressure gauge to the fuel rail and place it where you can see it from drivers seat, power brake (hold the brake, place in drive, and give it the gas to the floor for a few seconds), and watch the pressure gauge. (Assuming Auto Tranny)
 
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Discussion Starter · #7 ·
i have checked the fuel pressure underload two or three times and it's fine about 32 psi.
code 45 there are two of them, thermactor air upstream during self-test and the other one is coil 1,2 or 3 failure. i only have one coil!
 

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walton34 said:
i have checked the fuel pressure underload two or three times and it's fine about 32 psi.
code 45 there are two of them, thermactor air upstream during self-test and the other one is coil 1,2 or 3 failure. i only have one coil!
So not EGR, not fuel pressure.

Thermactor is basically just the air pump system for the CAT.

What is the condition of the CAT? Has it ever been changed. Is the upstream end of the CAT a bolt on connection that can be disconnected for a test?
 
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Discussion Starter · #9 ·
the cats are good there is plenty of air movment no restriction is detected, the truck has 92,000 miles on it . i wonder what it means about the coil and why would it show to code 45's ,that is strange?
 

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walton34 said:
the cats are good there is plenty of air movment no restriction is detected, the truck has 92,000 miles on it .
How did you measure for this?

I had an F-150 that needed CAT replaced at less than 100k. And you'd never have known it except under heavy load.
 

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OwlStu said:
So not EGR, not fuel pressure.
Actually, I take that back. It very well could be fuel pressure. At WOT the decrease of manifold vacuum should result in increase fuel pressure. Just like disconnecting the vacuum hose from the pressure regulator. Very possible you have a fuel flow problem.
 
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Discussion Starter · #13 ·
if the fuel pressure is low it would have to be the regulator because before i replaced it it was 80 psi so i know the pump has no problems and when i replaced the regulator i blew out the return line and replaced the filter on the supply line.Should i take the regulator back and get another one and what about the code 45
thanks
 

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Did you clear the PCM after replacing all the parts? The 80 PSI fuel pressure dropping to 32-45 could change how it runs under heavy load if the PCM had changed the long term fuel trim to compensate for rich readings it may have been receiving. Disconnect the battery for 2 minutes, if you haven't already. If you have, then disregard this post.
 
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Discussion Starter · #15 ·
No i didnt do that, I will give it a try. What do I do after that just drive it for a couple of minutes?
Thanks
 

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walton34 said:
if the fuel pressure is low it would have to be the regulator because before i replaced it it was 80 psi so i know the pump has no problems and when i replaced the regulator i blew out the return line and replaced the filter on the supply line.Should i take the regulator back and get another one and what about the code 45
thanks
Don’t confuse pressure with flow. Think of it like a garden hose and nozzle with the facet barely on. It will still reach full pressure while the nozzle is closed, but open it up and the flow is not there. Just because you have good pressure at idle doesn’t mean you can get enough flow at full load. As would be indicated by the drop in pressure.

By the way, is this a for real problem. I seem to recall an identical scenario given a few years ago on an email list. ‘The steep hill where I live’, ‘no full throttle power’, blah, blah, blah. And every thing anybody pointed out was, you guessed it, A-OK. Some of your responses seem as they could be 'canned' from a text book solve this problem, And when asked for specifics of how you checked for CAT/exhaust restriction. You just say “no restriction detected”, sounds like reading from a chart, and won’t give specifics of how you checked / know.
 
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Discussion Starter · #17 ·
lol,lol,lol,lol,lol,lol,lol,lol hell yes it's for real! lol,lol,lol,lol
still lol,lol!
this is my first ford and i'm not a ford man and was seeking help.if i forgot to answer a qoestion, the only thing i did with the cats was let my wife power brake it while i was feeling of the pipes and there was plenty of air coming out. I know it's not the best way but it,s the only way i know how.works pretty well on checys but i dont know about fords thats why i'm here lol.
what about the code 45 do you think i could have a bad coil?
 

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Could be but I’m rather thinking that code 45 for your truck is for the thermactor not the coil.

If you have a suitable pressure gauge you can drill a small hole in the exhaust pipe just before the CAT to hook it up. Rev the motor to about 2500 RPM to measure the back pressure. I’m not recalling for certain and most self repair books like Haynes and Chilton don’t get into this I don’t think. But I seem to recall from when the F-150 was tested anything above about 8 psi is supposedly too much. Or you could take it to an exhaust shop and have them check the CAT.

I still think you may have a fuel problem though. If the system was able to keep up with the flow demand the pressure wouldn’t be dropping. But rather rising due to less manifold vacuum at WOT.

There is a reason by the way that the fuel pressure jumps from 35 psi to 45 psi when you remove the vacuum line from the pressure regulator. It’s so that under heavy load such as WOT and manifold vacuum drops the fuel pressure will rise and increase delivery. But this can only happen if there is enough fuel flow capacity.
 

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walton34 said:
i have checked the fuel pressure underload two or three times and it's fine about 32 psi.
code 45 there are two of them, thermactor air upstream during self-test and the other one is coil 1,2 or 3 failure. i only have one coil!

fuel pressure should be around 40psi. if you haven't already, put a high-output ignition coil in it. i put the accel HEI coil in with my tune-up, and gapped the plugs to .50, and it really woke my 300 up.
 
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