RRC running really bad

[az_max]

Over the past couple of days my truck has run rough for a couple of minutes (missing cylinders, no power), mostly on cold startup. If I let it sit for a minute, it goes away.

Well, today leaving work it started it again, but it got worse. Low idle, missing cylinders, popping through the intake, no power when accelerating. And the check engine light came on.

less than 3000 miles on rebuilt upper end.
new:
plug, wires, injectors, fuel regulator, cap, rotor, coil, hoses, water pump, etc...
Rebuilt heads

I have the amp kit on my desk, haven't had time to install it.

To me, it seems like a timing or under fuel issue. Don't know what else to check. Ideas? Will the LEDs on the passenger side give me usable codes from the ECU?

 

[Nomar]

Is your big hose from maf to plenum ok? No holes?


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[az_max]

Is your big hose from maf to plenum ok? No holes?


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it's new too. I checked both ends, but didn't look for holes.

 

[Ren Ching]

maybe one of those flaky rotors.

 

[jims95]

When the symptoms start, pull over stop the engine, and disconnect the harness from the MAF. Start it up, and if it runs normal in default mode, the MAF is going bad.

My RRC did this a few years ago. I found that it normally runs fine when cold from the start, then gets flaky after the engine warms up. I even disconnected and reconnected the MAF multiple times to convince myself that the truck would only run normal in default mode.

Hope this helps.

 

[az_max]

When the symptoms start, pull over stop the engine, and disconnect the harness from the MAF. Start it up, and if it runs normal in default mode, the MAF is going bad.

My RRC did this a few years ago. I found that it normally runs fine when cold from the start, then gets flaky after the engine warms up. I even disconnected and reconnected the MAF multiple times to convince myself that the truck would only run normal in default mode.

Hope this helps.

*ding* we may have a winner. I unplugged the MAF sensor and started it cold. It idled fine and didn't drop in idle speed after revving it up. When I turned the truck off, connected the MAF and restarted, it didn't idle smoothly and revving it dropped the idle to a stumble when I let the throttle go.

 

[discostew]

Did you check the price on that yet? I wonder if it costs as much as a GEMS Mass Air Sensor. I would find a good used one if its expensive. Instead of a cheap knock off.

 

[az_max]

Did you check the price on that yet? I wonder if it costs as much as a GEMS Mass Air Sensor. I would find a good used one if its expensive. Instead of a cheap knock off.

$440 including core charge from AB. I'm headed to the Parts Wanted section to see what's available.

 

[az_max]

Well, I thought that would fix it. I cleared the computer by unplugging the battery for a while, put the replacement MAF in place and....

It ran the same. It's like it's missing a cylinder or two, stumbling and missing. I let it run for a while (charging the battery) and after about 5 minutes, it cleared up and started running OK. It was short lived though, because the check engine light was back on. :banghead: FWIW, it seems to be the passenger side.

Also, I have a small coolant leak where the TB heater hose comes out of the intake. May need to remove it and find a way to seal it.

 

[jims95]

You might want to borrow a MAF from a truck without the problem, and cross check with the replacement you got, on both trucks.

Sometimes a used part may not be in any better condition than the one you replaced. It has happened to me.

 

[az_max]

I don't know if you can hear it well enough in this video, I'll get another today.

https://goo.gl/photos/kcaiWmLFvyDaxcEX7

 

[az_max]

I had a little time after work today. With the MAF unplugged and the check engine light on, the code box under the passenger seat reads 45. That's listed as O2 sensor Bank B. I didn't get a chance to reset the light and plug in the MAF. I want to see if the code changes.

 

[az_max]

It's at Huffs. there's a few things they want to change, one being the O2 sensor. We'll see how it goes.


BTW, Rov-n-techs wont work on anything older than 1995.

 

[az_max]

Had huffs put in the BP ignition amp relocation kit, and the tech couldn't get the truck started. Putting the original one back in worked

 

[az_max]

I drove the truck home 25 miles, and put another 25 miles on it today. Dave at Huffs has my truck purring like a kitten. Decent power for a 3.9 in a 2.5 ton truck. Towed the trailer up small local hills without issue. Temp gauge stayed in the middle despite 103f outside temps. atriot:

Next week is an Elk hunting trip up in 4a, then LR rally in three weeks.

Need to call BP monday and see if they'll RMA my amp relocation kit.