(Long winded... Beware) Sputtering and popping, loss of power a

[Maseman__46]

Hey guys, first post here, but I've done a ton of reading on this site and it has been great. Before I start, I will say that I have searched high and low for hours on end, tried every suggestion I can find and have eliminated pretty much all of the problems but 2. So I have an 88 ranger with the A4LD trans, but the engine was replaced with an 87 with a manual trans. They also swapped the harness and pcm, and totally botched the wiring. I have torn the harness apart, corrected everything based on all the diagrams I could find (soldered and heat shrink tubing) The issue is that it idles great, and will run fine until above 2500 RPM. I put the rear axle on jack stands as the TCC was locked up and had to fix it. It is having some odd shifting issues, so I can't drive it yet. I have cycled all the gears manually, but it continues to do the same with it in gear. I have replaced all of the following (verified they were bad)
TPS (throttle stop screw was adjusted all the way in, so i backed it off till it hit 500 rpm with the iac unplugged, voltage at .94)
ECT
Fuel pump (from a 1990, eliminated the canister, tank selector valve since t he rear tank was removed and the high pressure pump)
Fuel pressure regulator
Fuel filter
Replaced pcm with a 1990 auto
Upper and lower intake gaskets (leaking)
TFI module
O2 sensor
Swapped ignition coil from my f150 (1996 5.8)
Plugs, wires, cap and rotor
VAC lines, as well as trans modulator

Things I have verified are ok
IAC (cleaned and verified correct operation)
Timing (set at 10* with SPOUT connector unplugged, advances to 28* with it plugged in)
O2 sensor voltage (fluctuates between .2 and .6 at idle, stays around .6 with any throttle, which I know is a tad rich)
EGR isn't hooked up, but it's still there. Verified no leaks
Fuel pressure is 40 with engine off, 30 while running and 45 with the FPR unlocked (fluctuates rapidly above idle)
Verified MAP sensor ref voltage, and output HZ according to alldata
Checked/cleaned all grounds
Bypassed inertia cut off switch
Engine vac at idle is a stead 16 or 17
Probably other shit too

Normally, I'd just junk the thing, but it's sentimental as it is sentimental to the owner. I am at wits end with this damn thing, and now it's more of a personal vendetta... I may have done/tested other things, but can't remember. Thank you to everyone in advance, and for all of the solved issues from past posts!

 

[rusty ol ranger]

Injectors

 

[Maseman__46]

Well, I have unplugged them individually with a definite change, and they all check out (as far as hot continuity) Tho, in hindsight, I probably should have just taken them off when I removed the intake. I will definitely give that a shot when I get off, thank you.

 

[rusty ol ranger]

Well, I have unplugged them individually with a definite change, and they all check out (as far as hot continuity) Tho, in hindsight, I probably should have just taken them off when I removed the intake. I will definitely give that a shot when I get off, thank you.

The 2.9 is a batch fire system. The ECM fires one whole bank at a time. Unplugging them one by one wont really tell you a whole lot (i dont think).

The 2.9 is also very well known for rusting the fuel rail...that can clog stuff too

 

[Shran]

EGR isn't hooked up, but it's still there. Verified no leaks
Fuel pressure is 40 with engine off, 30 while running and 45 with the FPR unlocked (fluctuates rapidly above idle)

What isn't hooked up on the EGR? I believe the valve itself is vacuum operated? Plus it has a position sensor and purge valve... if it's all unplugged and you're sure the valve is closed, I suppose you could more or less rule that out but it can do funny things if part of it is functioning.

Your fuel pressure shouldn't fluctuate rapidly... if you blip the throttle it should respond accordingly but it should settle down somewhere in that range above idle and not move a whole lot if the engine RPMs are steady.

 

[rusty ol ranger]

Just curious....have you pulled codes?

 

[Maseman__46]

Shran, that was what I thought, but I've checked the fuel pump voltage (13.8 while running. Ran all new fuel lines, it holds pressure when turned off for a while (don't have an exact time) and have a new FPR. What is odd to me, is there seems to be 2 types of them. The one that was on the truck, and from all of the photos/posts I've seen, is labeled at "returnless". The other is labeled an adjustable return type. As far as the EGR, the engine is an 87, the pcm is from a 1990. From my understanding, 1990 rangers didn't use the EGR system. I just mean the valve is on the manifold (new gasket, valve doesn't leak) and the EGR tube (which was loose, but doesn't leak after I tightened it)

Rusty ol ranger: After taking off the injector harness, I see that now. Only other time I've seen is my 92 Jimmy (converted to a sandrail) which seems like a dumb design to me, but I'm not an engineer for a reason . I did pull the injectors, and the screens were dirty on 2 of them. The plastic pintle (caps?) Weren't dirty, and I was able to blow through them when applying power with my bench power supply. Before removing them, I pressurized the rail, and none of them are leaking. The resistance across 5 of them (OE) is 14.1, and the one that was replaced is 15.5. looking at this new one, the nozzle is significantly larger than all the others, but has no part number. I did blow out the fuel rail, didn't get any crap out of it tho. As far as codes, only a code 95 (replaced the fuel pump and eliminated the switching valve due to the other tank missing) on the KOEO test, and a code 41 on the KOER test

 

[rusty ol ranger]

Shran, that was what I thought, but I've checked the fuel pump voltage (13.8 while running. Ran all new fuel lines, it holds pressure when turned off for a while (don't have an exact time) and have a new FPR. What is odd to me, is there seems to be 2 types of them. The one that was on the truck, and from all of the photos/posts I've seen, is labeled at "returnless". The other is labeled an adjustable return type. As far as the EGR, the engine is an 87, the pcm is from a 1990. From my understanding, 1990 rangers didn't use the EGR system. I just mean the valve is on the manifold (new gasket, valve doesn't leak) and the EGR tube (which was loose, but doesn't leak after I tightened it)

Rusty ol ranger: After taking off the injector harness, I see that now. Only other time I've seen is my 92 Jimmy (converted to a sandrail) which seems like a dumb design to me, but I'm not an engineer for a reason . I did pull the injectors, and the screens were dirty on 2 of them. The plastic pintle (caps?) Weren't dirty, and I was able to blow through them when applying power with my bench power supply. Before removing them, I pressurized the rail, and none of them are leaking. The resistance across 5 of them (OE) is 14.1, and the one that was replaced is 15.5. looking at this new one, the nozzle is significantly larger than all the others, but has no part number. I did blow out the fuel rail, didn't get any crap out of it tho

You put a returnless FPR on a 2.9?

The 2.9 is a return feed system....

Also yes, a 1990 ECM doesnt care about an EGR as an EGR was only a 86/87 thing. But...make sure all the vacuum stuff is capped off.

I think youre on the right track...keep us posted.

 

[Maseman__46]

The fuel pressure regulator I bought was the same one that was on the truck, and seems to be the only one I've seen. I didn't see that it was a returnless style until much later. I get return vs returnless, it's just odd seeing other trucks with the same setup. All the EGR VAC lines are capped and the solenoid is gone, along with the feedback sensor

 

[rusty ol ranger]

You seem to know your way around so dont take offense but the regulator looked like this right?

 

[Maseman__46]

Yes, that's the one that was on the truck, and the new one I bought to replace it. The other has the vac line at a 90* angle. Turns out that injector is from some Toyota (doesn't surprise me, looked like it was wired by uncle grandpa...) I know a guy that has several of these truck just sitting aroind. Figure I'll see if I can get an injector and maybe the other style FPR
Oh, and don't worry, I wont get offended. I just want this thing done, and I know little things can easily be over looked

 

[Shran]

EGR - understood. Was just curious if the vacuum line was still connected to the valve itself. I could see issues if it's got vacuum pulling it open when you give it gas and that might explain the weird fuel pressure fluctuations as well. Disregard if the vacuum is capped off.

No 2.9 had a returnless regulator. Every Ranger had a return line up until 1998? or so? I'm sure you've got the right one and it sounds like it's more or less functioning correctly, the fluctuations are what gets me. I'd be curious to see what your vacuum readings look like at the regulator, do they jump all over with the fuel pressure reading? I did have a bad one on my truck that caused a low pressure issue, more proof that "new" parts don't always equal "functional" parts as it was only a year or two old.

Code 41 looks to be a lean condition, I did a little bit of reading on that. This thread was kinda interesting:

Persistent Code 41 KOER

Subject is a 1985 LTD LX with 5.0 HO CFI, identical to the setup that the Mustang used in 1985 with auto transmission. 156 K miles, new EGR, secondary air diverter, TAB/TAD solenoids. With engine off fuel pressure drops 1 to 2 psi after 5 minutes. Runs smooth but poor gas mileage and rich...

www.corral.net

 

[Maseman__46]

This is a screenshot from rockauto, but every other part shows the same thing. Ill put my little vac pump on the regulator and match the vac with my gauge on the engine and see what happens!

 

[Maseman__46]

I read through that article, and I just realized that even tho the code was 41, I kept thing it was 42 because it runs so rich... After I get the right injector and look at the other FPR's, I'll double check all that. If it persists, I might open the pcm and take a look, since this one came from a junkyard
Thank you for that!

 

[Shran]

Wut. I looked up a FPR for a '90 Ranger 2.9 and that is the only one that mentions "returnless." Furthermore, the other Standard part (PR17, not "T") mentions nothing about that.

I think this is a good time to mention that Standard brand "T" series parts are absolute junk in my experience. The fact that their description is wrong further reinforces my opinion.