Last time Ill make a post about this problem! D16A vtec running a P28 4 wire o2 works but im throwing 41 for the heater--it still runs pig rich. My car will occasionally run on 3cyls and go into limp mode (3.4k limit) We're talking very very intermittent..like throughout the revs itll go from 3cyls back to 4...it runs like garbage. New plugs and wires, cap and rotor look good and the dizzy is new anyways..i checked my injector wiring and def cant see any way it would be grounding out..i checked the pins at the ecu and at that black plug and it seems tight i suppose. Like I said, I get code 16. Most people tell me the injectors are prolly fine...so why would it run like this? Any ideas guys im at the end of my wits here

 

Bump

 

if the code is for the heater circuit do this simple check: Disconnect the o2 sensor and @ the o2 sensors connector check for continuity across the heater circuit wires, there should be continuity. If there is like Mega-ohms the o2 is no good. Then @ the engine wire harness side of the o2 connector turn the ignition to KOEO (key on engine off) and check for battery voltage @ the heater circuit power wire and check for continuity to ground for the ground side of heater circuit ground wire.
Get back to us with the results homeboy!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ryanplayjoint &raquo;</TD></TR><TR><TD CLASS="quote">if the code is for the heater circuit do this simple check: Disconnect the o2 sensor and @ the o2 sensors connector check for continuity across the heater circuit wires, there should be continuity. If there is like Mega-ohms the o2 is no good. Then @ the engine wire harness side of the o2 connector turn the ignition to KOEO (key on engine off) and check for battery voltage @ the heater circuit power wire and check for continuity to ground for the ground side of heater circuit ground wire.
Get back to us with the results homeboy!</TD></TR></TABLE>

Very true try that method but i might mention resistance on the heater circuit side is normal but too much resistance isn't. try a helms manual to see the specs on that. a heater circuit will have some resistance so check that out it should be obvious of a bad circuit if no continuity they its open.

 

sounds like u have a blown headgasket...

u sure thats not ur issue???

that happends when u have coolent seeping into teh cyl thus making it run on 3 cyl's in certain rpms where teh coolent leaks through...

also is the ECU chipped??

weird chipped ECU's tend to do funny **** like that...

 

well to the guys who suggested the o2 heater testing --great suggestions thanks..but you think that would cause me limp mode problems? Also about the HG--i highly doubt it--im running fine most of the time, not blowing any smoke, nor overheating. Anyone have any experience with other problems tripping code 16?

 

Yeah do you have a chipped p28? Because chipped computer do crazy ****. The obd-1 uses only one o2 so when it goes bad the ecu has to run on other sensors similar to cold running (open loop) You might have something else going on there but did you ever check the o2?

 

yea as i said its reading the 4wire o2..the sensor itself is brand new. And now the ecu is not chipped its a virgin P28...im running really rich also--like over .75mv thru my o2 sensor. Any other thoughts?

 

Well this problem has again resurfaced--

When I shut off the car, and leave it sit then go back to it, its no longer in limp mode. Ill drive it around and it will run fine all the way thru the revs. Then OCCASIONALLY, it will sputter--injector 4 will not fire. I replaced the injectors, so I know its not them. anyways, it throws code 16, and still wont be in limp mode. Then, if it sputters 3-4 more times--it will go into limp.

so--im thinking its the injector wiring, however, how exactly can I check and fix this? do I just probe the #4 injector wire?-- Again I must stress, 95% of the time it runs fine vtec works and everything. --- So, What should I be looking for? Jeez im just confused.

EDIT* After reading this, I realize I'm not expressing myself in the most efficient manner; In fact I sound a little stupid. Please, all, don't hesitate to ask me to clarify even the smallest of details!


Modified by Coltmorris at 3:01 PM 9/2/2008

 

bump before bed

 

rewire the injector that misses straight to the ecu.

 

im going on a stretch here but chekc ur main relay. my std used to throw code 16 and my injectors were fine. some one on here told me to replace my main relay and ive never had the problem since. also like u it was really random.

 

Ok cool--I have some good relays laying around so Ill change it out.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by traxxasx &raquo;</TD></TR><TR><TD CLASS="quote">rewire the injector that misses straight to the ecu.</TD></TR></TABLE>

Ill give that a try--though im not quite sure of the pin it goes to

 

UPDATE: Changed out the main relay with a freshly and correctly soldered one--no change. Another observation though:

The missing in the 4th cyl only happens at low revs. Only! I checked and double checked, when my revs climb, the missing clears out. If im driving my car more aggressivly, with heavy throttle and high revs, the missing clears out, or does not occur at all. What could this signify?

 

change that injector, sounds like its sticking to me, or better yet get them all cleaned and flow tested.