1991 XLT 4x4 Has some issues

[Winona87]

Hi there,
I have had my Explorer for about a year now and have had a lot of issues with it, but still love it.
The most recent issues are that it will run for a while, warm up and then start stuttering when you slow down and stall out when you stop, it is possible to keep it running, but not easy. When this started it also started losing power. We were thinking the cat converter or the fuel pump with this, but not positive. It also gets really bad gas mileage now. The problem does not occur when it is cold, but it still runs rough and lacks power.
Second problem the button for my 4x4 just stopped working, not sure why.
Third, I have smoke coming through all of my vents when the truck is running, smells like radiator coolant, pretty sure it is the heater core going out or a leak, just looking for some advice on how to fix the problems.
Had some wiring issues a while back and have replaced the battery, crank censor, coil pack, did an oil change and spark plugs not to far back. Getting ready to get on all these issues and do some more routine stuff. Thought it was awesome to see the door hinge replacement directions, since mine slipped. Anyways, thanks for any advice.

 

[YBCold]

for the 1st problem i would clean the MAF sensor and the IAC. they are relatively easy to hanlde and replace the fuel filter

for the smoke its just the heater core gone bad but ive read that the first gen one is easy to replace and theres a thread on here about how to.

i dont know what to do about the 4X4 as i dont have it

 

[BlakeOfDoom]

I'm dealing with some similar problems. I would replace that heater core asap if it is leaking. I'm dealing with the same as far as the engine stopping at a stop. I would clean the MAF and the IAC. I'm going to replace the fuel filter when I get the chance; I hope it is the solution to my problem.

i would check all your electrical connections as well. there is not a check engine light coming on is there?

 

[Winona87]

I forgot about that actually, many of my dash lights have been staying on. My anti-lock light, e brake light, engine, and I think that is all. They go off when they feel like it pretty sure that is a sensor. I also think I have a fouled plug that isn't helping, but isn't the issue for this.

 

[hollywood.mike]

well as far as the heater core, its probably the easist thing on the whole truck. i have a 91 sport 4x4 and looked at one of the threads on here and was done in about 20 min (beer helps! lmao) anyway it was 4 screws to drop the cover under the dash, (remove the glove box to see easier) then the 2 hose clams and viola! it just drops out and then slide the new one up in! gotta love it. didnt even have to remove the dash! lol

 

[Bwana Bob]

Yes, heater core is very easy, and cheap.

You may have one or more fouled fuel injectors. Do not use a Fram fuel filter. They fail and dump dirt into your fuel injectors, which will cause hesitation, major loss of power, and poor fuel economy. I had this problem. After replacing the fuel filter with a Motorcraft type (from Advance Auto) it took about a month of dosing the truck with fuel injector cleaner at every fill-up.

Also check the fuel pressure regulator.

Bob