Hello all...Need any all help and advice I can get at this point

Hello, I have a 87 ranger 2.9 I recently got from a friend.
Big head ache so far and lots of time and money invested as well.

1. failed smog twice now and both 15/25mph are GP.
A. 1st smog failed at 15mph/gp with hc max 150, mine 440
B. 2nd smog failed @ 15mph 1160, and 25mph 249 was 43 passable.
C. failed evap, along with fuel cap.

2. After 1st fail: I had both Cats replaced, new o2 sensor, new egr valve, new fuel cap, Iriduim plugs, wires, cap, rotor, fresh oil change, new fuel lines from tank to first filter.

3. After Cats put on and roughly 100 miles in truck started losing power when warm( before egr valve was put on), so I replaced egr thinking it was getting stuck open. fixed the problem for a couple days.
After speaking with previous owner, made me think it was the fuel pump and assembly within the tank, being they replaced it with a used 1 of out a wrecking yard from another car altogether. I order new the new 1, installed, but waiting on the second(on rail) to come in along with the filter.
Saturday, I was researching the forums and reading possibly the TPS, so i pulled mine, looked alittle old but decided to get another, but once in the engine compartment i started truck and could hear vacuum leak. Found that is was line leading to the Auto trans and the Modular was faulty as well. So trip to parts store i get TPS, modular and new vacuum line and ran all new line. started and no more trans fluid in line and engine does not have anymore shaking like before.

4. I need to get cats back on( pending trip to get new gaskets).
So question is If once back on and other new pump/filter/lines are on and the truck is still dying and bogging down, what would be the problems now?
Only thing I can possibly think of is new computer, map sensor? I dont know what that sensor is that connects to the egr valve?
there is vacuum on the new egr valve which tells me the solenoid on the passenger fender is working proeperly?

Sorry for such a long post, just trying to detail all what is going on and what has been done. I am sure I am leaving some detail out, and which I am sorry.

I would wait till you have all the parts you've ordered installed and then go from there. Have you pulled any codes from it? It's much easier to diagnose with them. You may have already fixed the problem and don't know it yet. Let us know how it's running when the parts are on and if you can get the codes read. Good luck.

Thank you for the reply. I will for sure let you know. Trying to connect with my neighbor that has the reader. Heading to Parts store now to also replace the pcv and gromet, along with new fuel line for when the pump/filter arrive.=)

EGR valve shouldn't have vacuum on its hose at idle, or any RPM when engine is cold.

EGR valve's vacuum hose comes from EGR vacuum modulator, the computer opens modulators valve to send vacuum to EGR Valve to open it.

First thing I would do is to pull off the vacuum hose at EGR valve a plug it.
See how engine runs.
EGR valve is only used when engine is warmed up and when it is under load, i.e. accelerating or climbing a hill.
By adding exhaust gases to the intake it makes the air/fuel mix burn slower, this produces less heat, and less heat means lower NOx numbers, which spike very high when engine is under load.
It also reduces the chance of pinging/knocking using regular gas, which can be caused by cylinder getting too hot, so EGR valve is like the thermostat for the cylinders in the engine, it only opens to cool them down when load on engine increases.

First see if the EGR valve is causing the bogging, by disconnecting it's vacuum hose and plugging the hose so you don't have a vacuum leak.
Then you can move on the EGR modulator.

Thanks Ron!

I have done this with the new egr while engine is warm, took off line, plugged hose and no change in engine idle at all. This means egr is working?

Not sure what you meant about the modular?
Thank you ahead of time.

You said in an earlier post that EGR had vacuum at the hose?

That should have made the engine run rough.

So then there is no vacuum on the EGR valve's hose at idle, or very very little, right?


Vacuum hose for EGR system should be similar to this:

Intake manifold==========EGR solenoid/modulator=======EGR Valve

Computer opens and closes EGR solenoid/modulator to add or cut off exhaust gases going into engine, it it will also have 2 wires connected

That is correct Sir.
plain idle no change, nor vacuum
slight rev little vacuum
solenoid on fender wall is also from a wrecking yard they visited, Possible faulty?
And your Diagram is spot on=)

Hoping it is ok. Previous owner again stated they replaced it from a bronco 2 out of a wrecking yard also. Most likely will end up replacing it also.
Trying to make the truck the most sound as I can via new part and all.

Figure I give alittle update.

Still awaiting 2nd pump to arrive along with new fuel filter, ( Fedex mix up).

So After replace the full assembly within the gas tank, new trans modular and complete new vacuum line, and replaced afew other lines as well. Also replaced the pcv and gromet. Truck is running even worse. The more I replace the worse it is getting. At idle the truck sounds beautiful and smooth, rev up some, bogs down. tried to back out of the drive way and reverse is soso, in order to get it back where it was parked I would either have to let it idle up or slam foot full throttle.
Is my ecm bad or faulty?
Local wrecking yard has one but the last letter is a B, as my current ecm is an A.
Ideas?

All your activity is messing with 29 yr old connections. On a carb this would be a bad accelerator pump. On fool injection it could be a TP sensor. Wild guess . is there any slack in the throttle cable? Are the plugs black? I would replace the coil(s) So Far in 5 yrs and 5K miles The Rat is costing about 70 cents a mile. I have a great running 135 K mile 4.0 OHV that freaken purrrs Outside of the that the truck is falling apart I ve taken it into the 2k $ area parts and service so far with no end in sight. I started with a 600$ project. I have come to think that a 94 4.0 5 spd, 4x4 is about the best for a shade tree hacker such as myself.

Another update.

2nd pump(rail) came in along with filter. Filter was very nasty and the fuel that was in there was as dark as dirty oil( very black).

So, after letting the truck warm up I rev up in the driveway, after 3 times it started to bog down again. Thinking it might of been the rest of the dirty fuel in line, I took it around the block 4 times, with each time appearing to run alittle smoother.

Parked in driveway, took hose off egr valve at egr, no difference in the engine either way, rough or smooth, constantly the same. I can feel air coming out egr port however.
Does the mean the solenoid that the vacuum goes to is bad? MAP sensor bad?
Also, there is a brand new tps on it.

I would still plug the EGR Valve vacuum hose and try running engine without EGR valve.

Yes, could be computer, you can visually inspect it's 60-pin plug for corrosion and open the top to see condition of circuit board.
There is really no way to test these, you can test the wires from connector to each sensor/control, these computers all work from supplied data, so "garbage in=garbage out" is the rule, if computer gets bad data in then it will run engine incorrectly.

If you slowly increase RPMs, while stopped, does the engine start to run rough and then smooth out or just continue to run rough?

Long shot but free to test is the Rotor in distributor, pull off cap and see if shaft is loose, have someone crank the engine while you watch rotor, you are looking for a wobble.
Also look in the cap for signs of rubbing on the spark terminals.

You can test MAP sensor with a multi-meter that has a Hz or kHz setting.
155-160Hz with engine off key on, sea level to 2,000ft
As you suck on the MAP hose(apply vacuum) it should start dropping down.
If testing at idle then you should see about 100Hz
If you "blip" the throttle it should jump up close to 150hz as vacuum in intake drops

Question about the TPS. Does the actuator spring back to the home position, or does it rotate and not spring back.

Just wondering. I had one bad from the parts store, and another user of the forum had the same issue with his F150 recently. The return spring in the TPS was defective.

S-

While driving around the block 4 times, I stopped in the street and 30-45 of idling there in gear it shot down to the 500 rpm range, once back in the driveway Is stopped again and down to the 500 range with it stalling this time.

Going to try what you said about the egr etc.
My local parts store said it would take a week before they can get the solenoid, if at all. Rockauto gives me a 2 week window, sigh.

If you slowly increase RPMs, while stopped, does the engine start to run rough and then smooth out or just continue to run rough?
It smooths out, every once in awhile it wants to drop to 500rpm and then stall out. But once i start to increase rpms it smooths out immediately.

Also, now when warm/hot out or uphill driving the truck loses 80% power.
Is do to bad intake air sensor and/or egr valve pressure sensor or both. Or even trans output sensor?