88 Ranger 2.9 fuel pressure issues??

[CzyRanger]

On your timing, shouldn't the 10 degree mark be lining up WITH THE POINTER? Not in between the pointer and the eyelet..? It's been a long time since I had to time a 2.9, let alone, work on one, so I can't remember what the timing pointer looks like.

I guess what you're trying to say is that you timed it with the SPOUT unplugged at 10 degrees, then when you plugged in the SPOUT, the timing mark was then showing up between the pointer and eyelet??

You might have to look through the tech library on here, or Google search is sometimes easier, and find the procedure to check the TPS. It's not hard at all. I located one page for you here: https://www.therangerstation.com/forums/index.php?threads/how-to-adjust-tps-sensor-ford-fuel-injection-models.66515/

You didn't forget to plug in the coolant temperature sensor did you? That may effect idle as well.


Hopefully others will chime in before I have you on a wild goose chase. lol

@Bird76Mojo
Thanks again for the help. I found this video on YouTube. I'm still going to use a sewing needle to probe the wire once i find out which one it is. But according to this video i can just touch the ground on the multimeter to the negative side terminal on the battery. Is that correct? Don't mean to beat a dead horse... just want to get it right. Video below. Thank again Bird76Mojo

 

[PetroleumJunkie412]

@Bird76Mojo
Thanks again for the help. I found this video on YouTube. I'm still going to use a sewing needle to probe the wire once i find out which one it is. But according to this video i can just touch the ground on the multimeter to the negative side terminal on the battery. Is that correct? Don't mean to beat a dead horse... just want to get it right. Video below. Thank again Bird76Mojo

Correct. Super easy process tbh.

Before I switched mine to a standalone ECM, it prefered running with the TPS around 0.90 volts. No idea why..

 

[Bird76Mojo]

Correct. Super easy process tbh.

Before I switched mine to a standalone ECM, it prefered running with the TPS around 0.90 volts. No idea why..

@PetroleumJunkie412 you think I'm steering this guy right or no? The lack of other people adding suggestions has me questioning my own diagnostic skills. lol

 

[PetroleumJunkie412]

@PetroleumJunkie412 you think I'm steering this guy right or no? The lack of other people adding suggestions has me questioning my own diagnostic skills. lol

Not at all. I haven't had much to contribute because you're covering bases pretty well and steering him in rhe right direction. Lean code is a b*tch on an EEC-IV.

I'm questioning his ECM and throttle body gasket seals, but not sure if he did the propane test. The brake pedal issue still has me convinced the whole thing is vacuum related.

Also wondering if his gas cap or evaporative line from the fuel tank is intact. A year or so ago I had something sorta similar going on with mine. One of the freaky things that greatly helped smooth out a rough idle that would bounce rich to lean was rebuilding my charcoal canister with fish tank filter charcoal I picked up at petsmart.

 

[CzyRanger]

@PetroleumJunkie412 you think I'm steering this guy right or no? The lack of other people adding suggestions has me questioning my own diagnostic skills. lol

@Bird76Mojo
Well here is the video of the test in the TPS...

Additionally... Here is a video directly after testing....

 

[Bird76Mojo]

You can do that TPS voltmeter test with the engine OFF and the key ON. It doesn't have to be running. The TPS seems to be working fine. On the 2nd test you did the voltage seemed to rise smoothly with slowly increasing throttle. The TPS voltage being at 1.1 at closed throttle is a tad bit high. Not sure what to think about that other than maybe the throttle stop screw could stand to be backed out a little bit, but if the idle speed is acceptable to you now, then I wouldn't do that.

If the brakes are still hard to press, you either have a vacuum leak to the booster, not enough vacuum due to a larger vacuum leak somewhere, or the booster is leaking vacuum internally somehow. That's my guess..

I have no idea why your idle came back down to normal levels now. That's odd indeed..

 

[PetroleumJunkie412]

You can do that TPS voltmeter test with the engine OFF and the key ON. It doesn't have to be running. The TPS seems to be working fine. On the 2nd test you did the voltage seemed to rise smoothly with slowly increasing throttle. The TPS voltage being at 1.1 at closed throttle is a tad bit high. Not sure what to think about that other than maybe the throttle stop screw could stand to be backed out a little bit, but if the idle speed is acceptable to you now, then I wouldn't do that.

If the brakes are still hard to press, you either have a vacuum leak to the booster, not enough vacuum due to a larger vacuum leak somewhere, or the booster is leaking vacuum internally somehow. That's my guess..

I have no idea why your idle came back down to normal levels now. That's odd indeed..

Brake booster leak makes the most sense to me.now. Have you put a vacuum gauge on the engine while.at idle?

If yiu don't have one, auto zone will usually lend you one, or Harbor freight has them cheap

 

[CzyRanger]

You can do that TPS voltmeter test with the engine OFF and the key ON. It doesn't have to be running. The TPS seems to be working fine. On the 2nd test you did the voltage seemed to rise smoothly with slowly increasing throttle. The TPS voltage being at 1.1 at closed throttle is a tad bit high. Not sure what to think about that other than maybe the throttle stop screw could stand to be backed out a little bit, but if the idle speed is acceptable to you now, then I wouldn't do that.

If the brakes are still hard to press, you either have a vacuum leak to the booster, not enough vacuum due to a larger vacuum leak somewhere, or the booster is leaking vacuum internally somehow. That's my guess..

I have no idea why your idle came back down to normal levels now. That's odd indeed..

So I'm thinking my next thing is to replace the brake booster then. I tried it a few more times and the RPM'S at idle are still back at 800. I wonder if me cleaning the TPS helped maybe. But anyway... Here's a video of what it sounds like now. Let me know what you think. Thanks again fellas! I really appreciate the help. ?

 

[Bird76Mojo]

If you unbolted the TPS to clean it, then you may have inadvertently adjusted it to the point it gives out a lower voltage to the ECM. Usually there's enough slop in the TPS bolt holes where it can be rotated the smallest amount.. That can change the voltages it supplies to the ECM. Which may have lowered the idle? At this point I'm forgetting when the idle came back down to an acceptable rpm. lol

Whatever works though!

That tick sounds like it could be in the valvetrain. The Ford 2.9's have that tick pretty often. Could be a weak/worn lifter, or air trapped in a lifter creating a little slop between the lifter and pushrod, which makes the ticking noise you're hearing. Engine oil pressure to the hydraulic lifters pumps them up and takes the slop out of the lifter-to-pushrod connection point, and the pushrod-to-rocker arm connection point. Think of the hydraulic lifters like an oil filled shock absorber. If there's low/no oil pressure to them, they have no oil damping effect to quiet down the valvetrain. After some driving it may purge the air from the lifter on it's own and quiet down. One of my old 2.9's did that in the past. Drove me nuts for a week after working on it and then one day it just stops ticking..

Of course, the clicking or tapping could be from something else completely. I can definitely hear it, but It's hard to tell from the video. If it's lifter tick, the sound should increase in speed at the same rate as RPM's increase.

It might not hurt to treat the old girl to a new oil filter and an oil change. Also, stay away from Fram oil filters. Lots of horror stories with Fram.. I always preferred WIX filters for my trucks. Some of the best filters in the industry, and they make filters for many other companies/brands. My other choice has always been Motorcraft.

 

[CzyRanger]

If you unbolted the TPS to clean it, then you may have inadvertently adjusted it to the point it gives out a lower voltage to the ECM. Usually there's enough slop in the TPS bolt holes where it can be rotated the smallest amount.. That can change the voltages it supplies to the ECM. Which may have lowered the idle? At this point I'm forgetting when the idle came back down to an acceptable rpm. lol
Whatever works though!

That tick sounds like it could be in the valvetrain. The Ford 2.9's have that tick pretty often. Could be a weak/worn lifter, or air trapped in a lifter creating a little slop between the lifter and pushrod, which makes the ticking noise you're hearing. Engine oil pressure to the hydraulic lifters pumps them up and takes the slop out of the lifter-to-pushrod connection point, and the pushrod-to-rocker arm connection point. Think of the hydraulic lifters like an oil filled shock absorber. If there's low/no oil pressure to them, they have no oil damping effect to quiet down the valvetrain. After some driving it may purge the air from the lifter on it's own and quiet down. One of my old 2.9's did that in the past. Drove me nuts for a week after working on it and then one day it just stops ticking..

Of course, the clicking or tapping could be from something else completely. I can definitely hear it, but It's hard to tell from the video. If it's lifter tick, the sound should increase in speed at the same rate as RPM's increase.

It might not hurt to treat the old girl to a new oil filter and an oil change. Also, stay away from Fram oil filters. Lots of horror stories with Fram.. I always preferred WIX filters for my trucks. Some of the best filters in the industry, and they make filters for many other companies/brands. My other choice has always been Motorcraft.

@Bird76Mojo
I didn't unscrew the TPS. I just pulled the connector off and cleaned both sides. So I am going to replace the brake booster tomorrow. I'm hoping that this will solve my issue. ?

 

[Bird76Mojo]

So I guess the only issue now is the hard brake pedal?

It sucks to have to replace the brake booster to find out. Too bad you didn't have a spare laying around from a parts truck or something.

If that doesn't fix the hard brake pedal issue then it has to be a vacuum related problem in my opinion.

Amazingly, I've never had to replace a brake booster in anything. So I'm not real sure on the procedure for doing that. I think it's a little technical. There may be an adjustment rod behind it that has to be the same length when installed in the new one. One might have to search the forum for those answers..

I do wonder about the brake booster check valve being bad. Not a common failure to my knowledge.. You might replace that first, as it would surely be much cheaper to replace than the entire booster.

Do the rpm's drop when you apply the brake?

Check this out: https://axleaddict.com/auto-repair/Bad-Brake-Booster-Check

 

[CzyRanger]

So I guess the only issue now is the hard brake pedal?

It sucks to have to replace the brake booster to find out. Too bad you didn't have a spare laying around from a parts truck or something.

If that doesn't fix the hard brake pedal issue then it has to be a vacuum related problem in my opinion.

Amazingly, I've never had to replace a brake booster in anything. So I'm not real sure on the procedure for doing that. I think it's a little technical. There may be an adjustment rod behind it that has to be the same length when installed in the new one. One might have to search the forum for those answers..

I do wonder about the brake booster check valve being bad. Not a common failure to my knowledge.. You might replace that first, as it would surely be much cheaper to replace than the entire booster.

Do the rpm's drop when you apply the brake?

Check this out: https://axleaddict.com/auto-repair/Bad-Brake-Booster-Check

@Bird76Mojo
No.... Now I'm just back to my original reason for posting the this thread. After I drive for about 3 miles or so the truck has a hard time with acceleration. I mean... I can get it up to 75 and probably more but I got to smash the gas pedal. It will start "popping/backfiring". It's only when it warm it seems. I was told that the booster leaking could cause a major vacuum leak and could be causing me to run lean. So anyway, yea, I wish it was just the hard brake pedal but no sir. ? Also, to answer your question... When I apply the brake the RPM'S go UP about 500 RPM'S.

 

[PetroleumJunkie412]

@Bird76Mojo
No.... Now I'm just back to my original reason for posting the this thread. After I drive for about 3 miles or so the truck has a hard time with acceleration. I mean... I can get it up to 75 and probably more but I got to smash the gas pedal. It will start "popping/backfiring". It's only when it warm it seems. I was told that the booster leaking could cause a major vacuum leak and could be causing me to run lean. So anyway, yea, I wish it was just the hard brake pedal but no sir. ? Also, to answer your question... When I apply the brake the RPM'S go UP about 500 RPM'S.

One other thing I thought about.last night.

May want to pull your ECM and see if a capacitor sh*t itself. 30 years is about the operational life on a Ford EEC-IV.

I agree with Bird though... I vote vacuum.

 

[Bird76Mojo]

Well, the link I posted states:

Common Signs of a Failed Brake Booster
Don't know if you have a bad brake booster?

Here are three common signs that your brake booster may have failed:

You need more effort to apply the brakes (stiff brake pedal).
The brake pedal doesn't return to its original position by itself.
The engine rpm goes down when you depress the brake pedal at idle.

So, I'm not sure about that booster being bad.. It may be vacuum problems after all.


This is the weirdest thing... So it's only after driving about 3 miles, which would warm the truck up a fair bit.. Hmm...

I would think the truck would then be in closed loop since it's warmed up. The ECU is actively controlling the air/fuel mixture.

The O2 sensor then comes in to play to tell the ECU what the A/F mixture is and the ECU adjusts accordingly.

So now I'm questioning all sorts of other things..

O2 sensor, TFI module, coolant temperature sensor, ECU, etc..



Diagnostics are gonna have to get more involved now. I'm thinking getting a vacuum reading would be good. Trying to pull codes again couldn't hurt either..



@RonD are you seeing this? Any clues? I'm running out of ideas here, and I hate for him to be throwing new parts at it until it's fixed, as that gets expensive quickly and is no way to work on anything.

 

[PetroleumJunkie412]

I'm really surprised @RonD, aka God, hasn't chimed in ?