I just bought a one owner 1993 Econoline cargo 4.9 I6 with just 70,000 miles on it. Was pretty clean.

Issue #1:

-The motor does not warm up.

-Temp gauge makes it to bottom line, just barely warm.

-Heater gets lukewarm not hot.

-Top radiator hose gets much warmer than lower hose (both get warmer than air, but not too hot to touch).


Issue #2:

-Airbag light flashes code 51.

-On the drive home from buying, at night, the dash lights did not come on, but headlights, heater/AC illumination, turn signal lights, bright indicator light, dome light, worked and all would dim, and horn worked. Just the gauges did not light.

-The next morning when I put the key in the ignition, the 5-5 beeping happened. That is when I peeled the black tape blocking the airbag light the P.O. applied and saw the flashing!

-Later that evening the dashlights worked again. They still work. The 5-5 beeping did not come back. The airbag light 51 code is still flashing.


Issue #3:

There is a bad stumble just off idle, and no problems running otherwise.


I know it is a lot, and I may have to start different threads, but I wanted to put this out there for some help if i could.

Thanks

 

I'd suggest replacing the thermostat, if it's stuck open or broken the motor will have a hard time heating up. The dash temp gauge on these trucks typically reads a bit low.. maybe just into the normal range, but it should get there relatively quickly and you should get plenty of heat.

The stumble off idle is likely a vacuum leak, these older trucks are prone to broken vacuum lines and rusted vacuum resovoirs, if you can get your hands on a smoke kit this will help ID any leaks in the system.

 

Thanks, I will try replacing the thermostat, that occurred to me.

I will also hook up my mityvac to check vacuum leaks and vacuum at idle. Where is the best place to hook up to it? I have only ever used it to set up turbo actuators on diesels.

I am a diesel head and know how to build one, but I have not had a gas motor in many years, and I never worked on them much.

Ideas I have had about the stumble include vac, fuel pressure (pump or regulator), throttle body cleaning, and spark/coil/cap tune up. EGR?

Any ideas on where the short may be for those gauge lights?

Thanks

 

1) 192 t-stat

2) bad ground possibly , Start there

3) tune up

do the basics first

 

I've got an 83 but it has the same block and its in the same generation. My temp gauge runs cool even after I've replaced pretty much everything. My heat ran luke warm at first because of a mostly clogged heater core. Mine was easy to replace from under the dash. Yours probably has more bits and pieces though. Do you have a temp gun to check how hot the engine is while running? I bet it's just fine. The lower radiator hose should be a bit cooler than the top one if the radiator/fan is doing its job.

 

had the efi 4.9 in my 89 F150, always had troubles with it running cold and taking way too long to even get warm. tried a 190 Tstat 1st and then a 205, and that made all the difference, faster to warm up and major fuel economy increase. the 205 was hard to find and not well listed but I was very happy with the results. if you aren't in the southern US it should work fine for you. the stock exhaust gets the heat out fast almost like a pair of headers so getting it warmed up is sometimes tough. my truck only had a single core rad , ran hot in AZ and NM in the summer but a bigger rad would have cured that.

 

The engine gets warm, but the upper radiator hose is never too hot to touch. I do not have a temp gun, but I know enough to realize that engine is not getting hot enough, the stock ford dash gauge inaccuracy regardless.

Until today, Its been pretty cool outside. Even drove on the hwy doing 65mph yesterday back from Virginia to NC, engine still never really got as warm as I feel it should. Heater ran lukewarm. Temp gauge really low.

Today was hot out. Did some running around town, then parked it at the house and idled a long time while I checked and inspected the vac hoses in the sunshine and heat. At idle, sitting in the driveway, the motor finally got hotter than it has been, and FINALLY the upper radiator hose got uncomfortably hot to touch.

Checked the heater and the air blows a lot warmer, borderline too hot to hold your hand by the vent. So the heater core may not be it.

68Mercury250Ranger, your advice is noted. I may find that 205 and try that. Either the thermostat is stuck open, or the thermostat is too low and everything cools too well. At idle in the driveway it did get hotter without the radiator's help.

Now, that stumble off-idle is much improved after I drove around a bit, after the hot-idle situation. The motor is now hotter, and the stumble IS NOT THERE. So, it only stumbles when its not hot enough.

What does that mean?

 

Went to the passenger side of the van under the hood. Unplugged the vac reservoir and checked only the reservoir for vac-seal with my mity-vac. It holds vac.

Next there is a black vac line running across the top of the engine bay on the passenger side which disappears into the rear corner towards the dashboard. There is a junction in that line. I unplugged that junction, that is, I unplugged the end going into the dash, and checked the vacuum out of that line coming from the engine.

Read 19.5" at idle.

Next I reconnected that junction and end going into the dash, but installed a "T" in that section and

Read 14.5" at idle.

Next I disconnected the two Red/Black lines going into the reservoir, sealed the black line, and checked vacuum on the red line.

Read 19.5" at idle.

Next I kept those two Red/Black lines off the reservoir, but ran a "T" line set up between them with my mity-vac connected in that line.

Read 14.5" at idle.

I dont have vacuum experience, I use my mity vac for diesel turbo actuator setup. I have no idea how to diagnose vacuum (no ignition or vacuum to fool with on my diesel).

What is going on?

 

Change the t-stat
It finally got hot enough to run right.

 

Yes but it still should not stumble like that off idle when cold. The condition is very noticeable and not right. Cold making it worse is a clue, but hot making it better doesn't solve it.

 

Is there any reason that I can't try the EGR block off plate to see if it helps?

I have an automatic transmission on the van....does that matter?

Also read that there could be a leak in the throttle body gasket. Worth a try, clean and regasket?

 

The choke is too rich
You are making a mountain out of a molehill.

 

EFI motor. No "choke".

OP: Fix the t-stat and reevaluate.

Check for vacuum leaks at manifold and anywhere down stream of air flow meter or whatever your motor uses.

 

Oops. What do they call it....idle air control valve?

Anyway, it's running too cold.
Why not fix the simple stuff before making problems.

 

Hi looking at issue #2

The airbag light & 5-5 chime.

The chime sequence is supposed to happen when the harness see's a loss of resistance through the airbag light circuit in the gauge cluster. So if the bulb fails the truck will chime.

The fact that you have it chiming while its illuminated is pretty weird to be frank. I think that your issue with having no dash lights and the airbag chime are connected.

I would remove the cluster replace all the bulbs then clean and check the contacts with the harness. See if that resolves the no dash light issue.

If the problem persists I would pick up a new headlight **** and switch assembly from the local scrap yard. See if that resolves the issue.

The airbag light muddog95 has a great diagnostic thread right here -->> https://www.ford-trucks.com/forums/9...1-or-51-a.html

Hope that helps,

-Mitch