87 running bad also...

[roady1269]

What I have:
87 Ranger Supercab, 2.9L, 5 Speed, 31" BFGoodrich A/T's, 2" sup lift, 2" body lift, Fiberglass fenders and bedsides, aprox 150,000 miles

I'll make this as simple as I can, runs like it has bad gas...now for a list of what I replaced:

1. Duralast premium cap and rotor
2. Bosh Platnium plugs gapped to .44
3. Taylor 8.8 wires
4. MSD coil
5. Ignition module on distrubitor
6. Canister fuel filter on frame
7. Retimed the motor to 10 degrees
8. Forgot about the temp sensor on front of intake

codes: 18 loss of tach signal ??? 41 Exaust gas oxygen sensor low voltage, always lean 31 EGR valve below min voltage

I think I got them right anyway

Starts and runs fine at idle. About a mile or two, it will start missing and acting like it has water in the gas, but only occasionally. Blows black smoke too. Usually it will last about 10-20 seconds before clearing up. Starting to do it a little more often though.

I am lost, any ideas?

 

[CraigK]

Try disconnecting the O2 sensor.

 

[almostclueless]

for what it's worth, Ive read that the insulation of the wiring to the TFI module can go bad, causing intermittent shorts.


Also, the pickup coil in the base of the dizzy "bowl" could be bad, even read good sometimes but vibration of motor running can change that....I believe the dizzy has to be removed and disassembled to change it, but if it's the problem...


With the tach signal indication, I doubt this is the case, but the fuel pressure regulator can cause bad running and black smoke.


So I'll sound like a broken record; consider getting a ford dealer shop to do a diagnostic instead of throwing parts at it.

 

[almostclueless]

Right here on TRS;

http://www.therangerstation.com/tech_library/TFI_Diagnostic.html


And finally, I hope you got a name brand TFI module. There's some cheap stuff out there.

 

[roady1269]

Ok, when I get the chance, I'll double check all the insulation on the wires.

I'll also try disconnectiong the o2 sensor, how should it run then?

What about that EGR thing?

I get a loss of tach signal error, WTF is that? how can I check for a tach signal?

 

[roady1269]

If the distibutor needs fixed or replaced, do I have to pull the engine to get that thing out?

 

[IMenriched]

If the distibutor needs fixed or replaced, do I have to pull the engine to get that thing out?

No it will come out without moving the engine...but it is snug! better with hood removed but not necessary.

 

[holyford86]

you will need to pull the upper intake to get the distributor out. make sure you clean the sand and dirt from around where the distributor goes into the motor before you even think about pulling it out. did you pull the spout when you timed the engine? your o2 sensor might be crapping out as well.

 

[CraigK]

I changed the distributor on my '87 BII without removing the intake. But try unplugging your O2 sensor before doing anything else. (If I'd done that first, I wouldn't have changed my distributor!)

CraigK

 

[grnrngr]

Just got my 90 Ranger back together, the distributor that was in the "new" motor was kinda rusty inside so I used my old one, had to pull and reset it because I was off by one tooth, didn't have to pull the manifold to get the dist out...

 

[roady1269]

Well, I disconnected the O2 sensor...MAN what a difference. It isn't perfect, but it stopped stalling and missing under load and I think its getting better mileage too.

 

[beauknowz]

.

that sounds exactly what my problem is on my 2.9

after warming up it acts up intermitently. if you floor it, sometimes it comes back up but not always. also it stalls a lot.
ive ran injector cleaner and super unleaded through it
new cap and rotor, cleaned the plugs.

ok, question, how do i know where the O2 sensor is?
and which one is the TFI module?
i think i know where the fuel pressure regulator is.

i know, stupid questions, but if i knew i wouldnt be asking.

thanks in advance.

 

[roady1269]

Well, my O2 sensor is located at the end of the y pipe on the exaust, just before the cat. If I am correct, the TFI module is on the back of the distributor, requires a special tool to fit the two bolts, kinda hard to reach, real pricy to replace, just did mine at about $45.

I ran like 3 bottles of lucas fuel system cleaner, 5 bottles of valvoline water remover and no luck. I unplugged the O2 and it ALMOST went completely away. It still has a slight miss and its running rich...remember, no O2 sensor to tell the computer the mixture.

Between all the stuff I already replaced, I probably have put close to $200 in it, now I need an O2 sensor.

Jamie

 

[Keith333]

Same problem with my 87 2.9L ...

Hi everyone,

I've experienced the same symptoms with my 87 2.9L 4WD Ranger. Mine would run fine, but then start stuttering and acting like it had no power. Then I'd shut it down and restart (5 speed) and it would run fine till the next time it occurred. This has actually happened to me on three separate occasions over the past few years.

The first time this episode occurred was about 3 years ago. I took it to a trusted mechanic and he replaced some do-hicky that was [visibly] busted but couldn't find the reason for the stuttering--cost me $160 NOT to have it fixed. It ultimately stopped after I just revved the engine for several minutes while removing and reattaching one of the vacuum lines. I found that odd, but was just glad it wasn't stuttering anymore. I figured I had some garbage in the vacuum (or somewhere) that was now dislodged and left it at that.

The second time this happened was about a year ago and I tried cleaning the contacts in the various wire harnesses. This seemed to help some, but ultimately it stopped after a simple engine wash (oddly enough). I figured there was oil and junk that was causing shorts and left it at that. Again, just glad it wasn't stuttering anymore.

The latest occasion had me even more baffled. None of the previous "fixes" worked. I played with the vacuum, cleaned the contacts, washed the engine good and ran some STP fuel system cleaner through the system--nothing. If anything, it kept getting worse and was happening more often. I'd make one trip to town and back, and I'd have to shut down and restart a dozen times. I had finally resolved to pay a professional to take a look, but decided to check on-line first. Man, am I glad I did!

After reading through the posts here last weekend, I went out and looked closer at the distributor. The wire harness connected to the side (that goes to the EEC?) was covered with oil and grim--something I'd never purposely cleaned before. I disconnected the harness from the distributor and pulled the wires (6 total) out of the plastic routing channel as far as I dared (12 inches or so) and thoroughly cleaned each wire with a rag and alcohol. 3 of the six wires were bundled together in some type of thin heat shield about 6 inches from the distributor, so I had to clean the heat shield in this case. I re-connected the harness, and the stalling and stuttering stopped altogether!

It still ran like it could use a good tune-up, but no stalling and stuttering like before. I still planned on the tune-up, but just this evening disconnected the 02 sensor just out of curiosity and, to quote roady1269, "MAN what a difference"! I guess instead of a tune-up for now, I'll be getting a new 02 sensor.

So, I just wanted to take an opportunity to share my experience with you guys and say THANKS for your post on this matter!

Take care,
Keith