Help

[first time]

I bought my first Ranger a couple month ago, 93 4.0 auto 4x4. The truck had set for almost a year before my buying it. I started with a complete tune up Plugs,Wires,Air filter,Fuel filter,oil change and filter, all ford parts.

The little beast started and ran great for about 1500 miles then developed a miss. I started with sensors TPS,MAF,02, IAC and bingo she is running great again. About five hundred miles ago I started having a intermittent problem. The truck feels like is bogging down or flooding out, it doesn't happen all the time just now and then. I have checked everywhere for a vacuum leak but cant find one. I can't find any sort of short in the wiring anywhere, My fuel pressure seems fine but I don't have a pressure gage to make sure but it doesn't seem like a bad fuel pump. I changed the coil pack and that made no difference.It sucks fuel and has no power when I am having the problem and runs great the rest of the time. By the way No Codes or check Engine light are evident.
The problem is occurring more and more often. Any ideas or help would be greatly appericated.
Thank You

Tom

 

[rangerluver]

Do you have good air flow through the tail pipe? I know once back when I was a kid my dad had a problem with a muffler or cat, not sure which, that had a flap of material (I am guessing something rusted) that would block the flow of exhaust through the tail pipe. Obviously it did not always happen but it gave the same symptoms that your truck is experiencing. Has the exhaoust been changed on yours yet? If not, 17-18 years is a long time.
Something else that just occured to me, do you have a good chassis/engine ground?

Just things that I would look at if I were having these problems. Hope it helps.

 

[first time]

Do you have good air flow through the tail pipe? I know once back when I was a kid my dad had a problem with a muffler or cat, not sure which, that had a flap of material (I am guessing something rusted) that would block the flow of exhaust through the tail pipe. Obviously it did not always happen but it gave the same symptoms that your truck is experiencing. Has the exhaoust been changed on yours yet? If not, 17-18 years is a long time.
Something else that just occured to me, do you have a good chassis/engine ground?

Just things that I would look at if I were having these problems. Hope it helps.

I just started the truck and there seems to be plenty of exhaust coming out of the tail pipe. I guess I can unbolt the system before the cats and see if it runs better. I am will to try about anything at this point. Thanks for the idea I have run out of things that I could think of trying.
The engine sounds fine and there isn't any missing or back firing. No over heating or water flow problems. I pulled the plug wires one at a time and they are getting good spark. The plugs seem to be fine showing a even burn. I checked the new air filter and it looks good. I did take the air inlet tube off the front of the intake and the truck stalled out I don't know if it should do that or not. Anyone know if this is normal

 

[first time]

I had someone suggest that I might have a bad Cam Position Sensor, Dose this seem rihght to you guys who know the 4.0 ????

 

[rags]

i would suspect the mass air sensor! I have a 94 with the 4.0 and mine start doing the samething! no CEL .. after checking all other areas .. i went and grabed a used one from my local wrecking yard and wow! truck ran like a new one! .. I talked to a few mechanics that told me they have seen mass air sensors be bad with no CEL.

You could try cleaning it with mass air cleaner. That sometimes helps and i heard you can unplug them and drive it .. but you will get a CEL if you do that.

Just something else to check out!

 

[first time]

i would suspect the mass air sensor! I have a 94 with the 4.0 and mine start doing the samething! no CEL .. after checking all other areas .. i went and grabed a used one from my local wrecking yard and wow! truck ran like a new one! .. I talked to a few mechanics that told me they have seen mass air sensors be bad with no CEL.

You could try cleaning it with mass air cleaner. That sometimes helps and i heard you can unplug them and drive it .. but you will get a CEL if you do that.

Just something else to check out!

Thanks Steve
I replaced the MAF sensor about a month ago. I guess it could need cleaning again. I will give it a try I bought a can of cleaner before I replaced the old sensor. anything is worth a try.

 

[first time]

Pulled the cats off leaving the exhaust open from the Y pipe, didn't make a bid of difference. On to the MAF

 

[powerranger262]

Did you check the plugs for the smallest cracks when you had them out?

 

[289-tiger-]

Good afternoon,

Check the vacuum lines at the manifold for dampness. ATF may be entering the intake causing the bogging from the modulator valve. Mid 90 RBV's will spit vacuum lines when the modulator is bad. The vehicle sat for a period of time, I would bleed the brakes and flush cooling system.

Good luck

 

[first time]

Good afternoon,

Check the vacuum lines at the manifold for dampness. ATF may be entering the intake causing the bogging from the modulator valve. Mid 90 RBV's will spit vacuum lines when the modulator is bad. The vehicle sat for a period of time, I would bleed the brakes and flush cooling system.

Good luck

Good idea I did replace the modulator valve. Why flush the cooling system ?
I will try it at this point I will try anything.
Thanks

 

[289-tiger-]

Good idea I did replace the modulator valve. Why flush the cooling system ?
I will try it at this point I will try anything.
Thanks

Good evening,

Good question

I would remove any fluids that sat stagnant to remove any of the nasty things that might have accumulated during a long period of unuse and suddenly cut loose in the system that could affect sensors or seals. It is cheap insurance (or used to be, but, coolant is not that cheap anymore).

Bogging on my unit was determined to be the MAF, no codes, replaced with cheap MAF, good performance for short period, MAF code appeared, threw cheap MAF as far as possible by hand into woods. Replaced MAF with quality unit...now finished replacing rusty rear leaf spring hangers.


And the beat goes on..........

Good luck

 

[first time]

Got it !!!!!

The problem was a bad air temp sensor. Put the new one in and BINGO I am driving again, Thanks for the ideas everyone.
For what it's worth anyone chasing a bogging no power problem I suggest Air Temp Sensor replacement code or no code

 

[powerranger262]

Where/what is the air temp. sensor? Are you talking about the MAF?

 

[first time]

Where/what is the air temp. sensor? Are you talking about the MAF?

No the air temp sensor that bolts into the intake. On my truck it's on the drivers side about halfway back. When this go's bad it causes the truck to run rich. Kills gas millage and power, can seem like the truck is bogging down. Mine is a two wire sensor was about a two minute change out. Because my truck wass down on power the tranmission didn't shift right. I thought I had a trans problem.

 

[erocka1982]

Did you check the plugs for the smallest cracks when you had them out?

ive been battling a similar problem for 6 months now and a small crack in my cyl 6 plug was the culprit this whole time. ive had the plugs out twice and always looked at the tip but never the ceramic part. finially figured it out last night accually! anyway, since your truck sat for a long time. try fogging the engine. it will help with your gas milage and stuff.
take a can of seafoam
fire the truck up
pull the vaccum hose off the brake booster that goes to the intake
pour the seafoam in that vaccum line
shut her off and let it sit for about 10 mins
then take her out and beat her up for about 20 mins
all your carbon should be cleaned out!!