Code 27, Bad Idle
#1
Code 27, Bad Idle
Hey guys, first I have to thank you all for your posts on these forums - it's helped me troubleshoot a large number of other things.
I've got a 1993 Dodge Ram 5.2 V8 automatic, and check engine light has been going on and off ever since I bought it in November. For the past couple weeks, it's stayed on and shows Code 27. Usually the check engine light would turn on right as I'm driving off the highway - when I'm slowing down. The truck would also idle badly. Not squeaky, just rough.
I noticed another symptom is when I hit about half a tank of gas. Could it be my fuel pump is going out? These days, it idles rough even with a full tank of gas.
Thanks for any help from Sam in North Carolina!
I've got a 1993 Dodge Ram 5.2 V8 automatic, and check engine light has been going on and off ever since I bought it in November. For the past couple weeks, it's stayed on and shows Code 27. Usually the check engine light would turn on right as I'm driving off the highway - when I'm slowing down. The truck would also idle badly. Not squeaky, just rough.
I noticed another symptom is when I hit about half a tank of gas. Could it be my fuel pump is going out? These days, it idles rough even with a full tank of gas.
Thanks for any help from Sam in North Carolina!
#3
Code 27 can be any of the 8 injectors... it does not mean injector #4.
I would start by trying to run some injector cleaner in the gas for a tank or two and see what happens. If nothing changes, then you have one or more bad injectors.
Copied from the '95 FSM...
I would start by trying to run some injector cleaner in the gas for a tank or two and see what happens. If nothing changes, then you have one or more bad injectors.
Copied from the '95 FSM...
FUEL INJECTOR TEST
Disconnect the fuel injector wire harness connector from the injector (Fig. 26). Place an ohmmeter across the injector terminals. Resistance reading should be approximately 14.5 ohms 61.2 ohms at 20°C (68°F). Proceed to following Injector Diagnosis chart. When performing the following tests from the chart, do not leave electrical current applied to the injector for longer than five seconds. Damage to injector coil or internal injector seals could result.
Disconnect the fuel injector wire harness connector from the injector (Fig. 26). Place an ohmmeter across the injector terminals. Resistance reading should be approximately 14.5 ohms 61.2 ohms at 20°C (68°F). Proceed to following Injector Diagnosis chart. When performing the following tests from the chart, do not leave electrical current applied to the injector for longer than five seconds. Damage to injector coil or internal injector seals could result.
You can download the '95 FSM from the faq page at the top of this section (in the stickied threads) for more testing and diagnostic information.
But it also sounds like you may have a fuel pump issue from what you said was happening before. You should get a gauge and test the fuel pressure at the rails.
Last edited by 95_318SLT; 05-01-2010 at 12:48 AM.
#5
Ok, it was suggested to me about a week ago to run fuel injector cleaner through. I've only had one tank refill since, so I'll wait for the next refill.
I've noticed my gas mileage dropped a couple miles - that normal in this situation? I'm guessing it's also entirely possible that several injectors could be bad, not just one.
I've noticed my gas mileage dropped a couple miles - that normal in this situation? I'm guessing it's also entirely possible that several injectors could be bad, not just one.
#6
#7
I had to deal with a code 27 as well. In my case it was a wiring problem and not the injector. The fact that your engine light goes on and off would mean it’s an intermittent problem; a fuel injector that doesn’t cycle throws the code right away. The check engine light also goes off pretty quick when the injector starts working.
If you don’t have an ohm meter i’d suggest waiting till your engine light is on at an idle and pull the fuel injector connectors one at a time while listening for a change in idle. When you find the one that doesn’t change your idle that should be your problem. Swap the injector’s position with one that’s working (put new orings on when you swap them). If your problem moves with the injector – get a new one. If the good injector stops working check for a wiring/ connector problem.
If you don’t have an ohm meter i’d suggest waiting till your engine light is on at an idle and pull the fuel injector connectors one at a time while listening for a change in idle. When you find the one that doesn’t change your idle that should be your problem. Swap the injector’s position with one that’s working (put new orings on when you swap them). If your problem moves with the injector – get a new one. If the good injector stops working check for a wiring/ connector problem.
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#8
As for the gauge not working, there is a write up in faq about a common cause of that.
#9
Sometimes my truck bogs down for a second and sometimes you can hear my exhaust note fluctuate noticably (I know that could just be the flow through my exhaust system, I'm just sayin cause it kinda goes together), could a bad injector do that or could it just be that my EGR valve isnt good?
Last edited by melodytoinvent; 05-24-2010 at 07:57 PM.
#10