1986 Ford Ranger 2.0 1bbl - Stumbling on itself

[ianthegreat]

Hi everyone,

1986 Ford Ranger 2.0 1bbl

Some of you may remember me from my other thread where we were trouble shooting some other issues and wound up replacing the head gasket and fixed some cooling issues. That was a few years ago.

I live in Pittsburgh now, but the truck sits at the family's house when I come back in town. It "maybe" gets 100 miles a year.

Now, I can't seem to pinpoint a new problem I'm running into and am reaching out for some guidance.

The truck is stumbling on itself and won't stay running unless I give it a lot of throttle - even then it definitely is stumbling/misfiring. The second I let off the gas it dies. Right as it dies I also get a backfire out the top of the carb, white smoke/fuel I'd imagine. At first I thought it may be running lean and that there was a vac leak. I did not have the time nor patience to navigate that maze again, so I ripped out all the emissions stuff and capped every vac port into the carb and intake manifold.

Tried starting again, same issue.

Thinking there may be a leak between the gaskets and the carb, I took the carb off, tightened the intake manifold, tightened up the carb and used some gasket sealant, then reinstalled.

Tried starting again, same issue.

I replaced the fuel filter thinking maybe it was clogged, no luck.

I then took carb cleaner and sprayed it down the carb while running, it actually bogged out.

I'm lost! Help!

**edit** also replaced the spark plugs
**edit** also checked timing, and it is correct

 

[ianthegreat]

I don't want to make it more difficult that it already is, but if I check the compression, is there anything specific I need to do with the distributor?

Or Can I just remove all the plugs, put the gauge in cyl 1, crank a few seconds, then check the value? Repeating for each cyl?

 

[Mark_88]

Welcome back Ian...was wondering what happened to you...last thing I remember was something about replacing the transmission or something like that...

Anyway...only thing you need to do is remove the coil wire from the distributor so it doesn't actually fire when you are doing the compression test...and I seem to recall something about WOT required to get a proper reading...on a carb I would imagine that means to simply make sure the butterfly is open so you are getting proper air flow for the intake to make the compression properly.

Here is a document that may be helpful...

http://www.boatfix.com/merc/Bullet/97/97_25.pdf

As for the symptoms you are seeing with the engine running (I don't think you need a compression test to correct the problem) it sounds very much like a vacuum leak...but the steps you took should have corrected that...only other thing is something internally on the carb may be plugged causing the fuel to not flow properly...

Maybe a carb overhaul would be a better step to take...you may have gunk clogging a passageway...that can happen easily if you are rarely driving the vehicle and there is gas sitting in the bowl...

I had the exact same symptoms you are describing...a friend took the carb apart, soaked it in degunk fluid (you can buy this by the gallon) and reassembled it...worked like a charm after that.

Hope that helps...

 

[ianthegreat]

Hi Mark, hope all is going well!

The last time I had to work on it the slave cyl had gave way requiring me to drop the transmission. Glad to not have to get under there again.

I appreciate the insight, all signs were leading me to the carb. I'll probably drag the carb up to Pittsburgh with me and fix it up there. Will be a nice little project until I can get back down to the truck. Maybe bring back a 2bbl

Thanks!

 

[ianthegreat]

One other thing, I capped the EGR valve. That ok? Do I even need it anymore? The top of the valve had a vac line running to it (capped now), the bottom fitting part has a tube that runs to the xhaust manifold. I imagine for some sort of re-circulation.

 

[Mark_88]

Well, wish I could say all was well with my Ranger but, alas, it is in need of a new motor. Working on that right now but it has been taking longer than I hoped...

The EGR may or may not be needed. The engine will run without it but the emission testing will fail if you need to have it tested. Can't remember if you were one of the fortunate ones who lived in a place where it didn't matter, but they can be sticky about it...I received a $365 fine for not having mine hooked up but was able to get the fine dropped when I showed them my copper tube EGR...lol

On my truck, I found the EGR tube where it fed to the bottom of the carb was full of gunk and not working properly. Had it capped at the base of the carb and it ran fine like that...until they caught me...

That could be a source of carb problems because the gunk can work its way in and plug things up around the base openings. Something you may want to check on if you haven't already done that.

 

[ianthegreat]

Will definitely look at that, the copper tube is about a 1/4 blocked from gunk so if that fed into the carb it could very well be the problem.

Who gave you the fine? If a police officer, I couldn't imagine them even knowing what an EGR valve is.

Sorry about the engine! You had it a very long time, over 400k right?

 

[Mark_88]

It was actually the Ministry of Environment. They were doing a roadside inspection and noticed it wasn't 't there…didn't have an air pump either and this was originally equipped with one.
The current motor only has about 200K and I just had the head rebuilt last year. I think the head is OK but the bottom end is sloppy…been trying to find one to just swap in but no such luck so far.

Anyway…cleaning the egr tube might help…that would be nice.