My truck wont't run run worth a crap once warm.

[RockRanger]

I was out driving it today for the first warm day this year. It is hovering around 100 degrees. Truck was running slightly warmer then usual on the temp gauge if I pushed it hard 70mph 3k rpm in 5th. If I backed down to around 65mph the temps would come back down. As I was driving on the freeway I noticed the check engine light came on for maybe thirty seconds then went off. Did it twice maybe 10 minutes apart from each time. After it went off I continued about ten miles and got off the freeway and pulled into the shopping center I was going to. As I pulled into my parking spot it started to sputter and not idle. I shut it off then tried to restart it and it wouldn't start at all. I went into the store to do my shopping (15 minutes), Came back and the truck would start run about 10 seconds then not idle and die. Went and grabbed lunch (45 minutes) came back truck started with somewhat of a rough idle and I was able to drive it home two miles and park it.

I ran my scan tool and I got 3 codes.

157. Mass airflow low voltage
186. Fault in injector pulse with circuit high.
528. Clutch switch circuit fault.

This is in a 93 ranger with a 4.0 and a 5 speed. Need to get this solved as I have a wheeling trip planned this weekend. Going to try cleaning the MAF sensor right now but am lost on code 186. Any ideas?

 

[FR-425]

DPFE

 

[RockRanger]

DPFE

Not following you here. Can you explain?

 

[FR-425]

@RockRanger

Differential Pressure sensor. (DPFE)
Part of the EGR system.

I suspect this due to the interment CEL while driving. It won't throw a code until the light comes on steady. Every time this happens on mine it's the DPFE.

The codes you are getting however point to a bad ECT. (except for the clutch switch, ignore that for now probably just pedal vibration i.e. loose bracket on the switch.)

My educated guess is that you have both problems at the same time. Common hot weather failures.

 

[FR-425]

Never mind the arrows, recycled image from another thread...

gizmo under the AIT. If yours is metal it has probably never been replaced.

 

[FR-425]

Not try'n to be smug. I assumed that since you've had this truck for 12 years you've been up this hill before.

 

[Albino 94LTD]

Your MAFS code ould be a loose plug on the MAFS. Been there did that now using a zip tie to secure the plug. The MAFS code could cause limp mode with preset air to fuel ratios

 

[RockRanger]

I have had the truck 12 years but only put 10k miles on it. The truck only has 198k on it. Did a quick look tonight and didn't see the piece you are talking about. I dont think my truck has it.

I cleaned the MAF sensor and the truck ran for a minute then died... Going hiking tomorrow and will mess with it on Friday. I bought a new MAF sensor that I can install if it comes to throwing parts at it. This is the first engine issue I have had. Only thing I have done to the engine before was a new fan clutch.

 

[Albino 94LTD]

Remember to disconnect the battery for at least 10 minutes to reset the ECM, especially if it has messed up fuel/air tune tables.

 

[FR-425]

@RockRanger
Yep, yours is non-EGR.

Well for sure a bad/dirty MAF will screw with the injector pulse width.
As always, work the codes in the order they appear. Not numerical order.
Once you clean the Maf and reset the PCM. Drive it for a minimum of three drive cycles and see if the codes come back. (drive cycle = cold start to operating temp, under normal driving, not just idling. if no code drive it again, rinse repeat.)
If you get the same MAF code replace the MAF after careful inspection of the wiring. Sometimes it's just the connector or wiring.

??what did you clean the MAF with?? carb cleaner, brake clean, acetone, windex and many other "cleaning" agents will ruin the MAF. Also important NOT to touch it with anything.

Once that is sorted you can work the other codes, if any.

 

[RockRanger]

Cleaned it with the silver can "mass air sensor cleaner" from the local parts house. Going to disconnect the batterry first tomorrow and see if that does anything. If the cleaning and that doesn't solve my problem then I will install the new sensor.

 

[Stic-o]

Sound similar to the problem I had with my old B2 with the 2.9. Ended up being a module on the back top of the motor. It would get warm and just die. Would not run again till it cooled off again.

 

[RockRanger]

Driven the truck on a few 10 minute runs around town and so far so good. Going to load up and head for the mountains to go do some wheeling. Bring the spare MAF sensor. If I have issues I will swap it in.

 

[Stic-o]

Good luck.

 

[RockRanger]

Got half way up the mountains and the truck went to crap. All I could do was 30 mph in second up the hill. Nursed into the campground and unloaded camp. Swapped the new MAF filter in an disconnected the battery. Truck runs okay now. There is still something not quite right though. Seems to have a bog and stumble that was also there before this event. It ran well enough to wheel till 230 am Saturday night. Then run another trail this morning to one of the lakes to do some fishing. Then drove 75 miles home. Will pull codes again and see what comes up.

 

[2stroke]

Something similar happened to my 94 explorer back when I daily drove it. Every time the CEL would come on, the engine would bog and it would barely have any power. Then the CEL would turn off and it would instantly have full power again. Ended up being the ICM. I don't remember which codes there were, but I do remember they didn't seem to be ignition related. Put in a junkyard ICM and the problem never came back.

 

[RockRanger]

Wednesday morning we loaded the truck up and headed up the mountains for three days of camping. Truck was running great. Then we came up to the "4 lane" it is a 4 lane section of highway that has a roughly 8 percent grade that takes you from 1700 feet to 4500 feet elevation in around 10 miles or so. It was around 100 degrees at the bottom and upper 80s at the top.It is one continues grade with very little if any flat spots. The truck pulled the grade slightly warmer then normal. Temp guage ran between the R and M on normal. Truck usually runs right at N. Got to the top of the hill and into town at about 5800 feet and truck wouldn't run at all. Grabbed some food and let the truck sit with the battery disconnected. It started up but never run if the rpms fell below 2000. Wheeled into the lake and anytime the rpms fell it would die. Only way to get it to start was to disconnect the batterry then hold the rpms above 2000. We made it to camp and let the truck sit for one full day. I left the battery disconnected for abot 12 hours. Loaded the truck up this morning and it fired up and ran fine. Drove it all the way home down the grade and no problems. Outside temp is around 105 in the valley. Temp guage a few times hit O.

Any ideas?

 

[2stroke]

I would check your fuel pressure after or during a hard run. If its good, I would consider replacing your camshaft position sensor.

 

[natenkiki2004]

In reading you progress through symptoms, I'm thinking like 2stroke and wondering if it's your fuel pump. Might be intermittent or when it gets warm it starts cavitating or something. Simplest thing would be to hook up a gauge and run it that way for a little while since you can almost reliably get it to act up.

 

[RockRanger]

So I ran up the same hill today. Similar temps but truck was about 600 lbs light with no camping gear. Ran great till I got to the top then it took a crap again on me. Before I left I bought a fuel pressure gauge at Harbor Freight. Hooked it up when it wouldn't run and had 15psi at the rail. Got it to fire up at one point on the side of the road and got to about 25 psi for a few seconds then dropped down to 15 psi and died. I sat on the side of the road for about 40 minutes and got it to fire up. Turned around and headed down the hill. Truck ran horrible for about a third of the way down the hill. then it came back to life and ran fine the rest of the way home. Got home where it was running fine and it had 32psi. I let it idle a bit in the driveway and the fuel pressure fell off and it died. I got it to fire up and pulled into the garage. Currently have the fuel tank pulled apart to go get a new fuel pump. What about the fuel pressure regulator?

It just sucks that my "test hill" is 35 miles each way from house. However nearly all the local wheeling trails are at the top so I have to get this truck to be able to climb the hill. I have till Tuesday night to get this solved.