After completeing a stock to stock swap, my 94 prelude "starves for fuel". When cool runs just fine, once it warms up it gets sluggish and lunges every so often. feels like its not getting enough gas. When downshifting seems to lose power, same with shifting up too. Dont know what the issue is. ECU? distributor? This was a US stock engine to a JDM engine. What am i missing here?

 

Well mabey you should just swap out the old parts off the usdm one and put them on the jdm one.

Or it could be timing is off. Id have that checked first.

 

join us in our mission here https://honda-tech.com/zerothread/2107210

 

like acid said, it could be your timing....


or

what did you do to the engine when you installed it? did you do a full tune up?

 

Well 1st.. do a resistance check on all the injectors make sure all reading are almost
the same if you need specs let me know.

2nd... put the all the ECT sensors from old engine to the new one.
the engine doesn't use sensor input during warm-up, it uses pre programed fuel map
it is harder to automize the fuel with a cold engine. check for fuel trims and DTC's even if you have a check engine light. it takes emissions devices priority to set a MIL.

3rd... pinch the vacuum line going to the fuel pressure regulator at idle. if the engine revs by it self then its working good, if it dont replace. and the fuel filter.

4th...check for vacuum leaks, whitch in turn could increse the amount of air going in
making a lean condition (a.k.a unmetered air) due to not reciving an fuel supply since the ecu doesn't know of the event happening

5th... check for air pockets in the cooling system, having a lot of air in the system could lead to a missed imformed ecu when the sensor(ECT) is in between an air pocket the sensor sends a signal saying i feel a super cold temp so the ecu says oh ok so am gonna cut fuel to compensate since most cars including honda use a NTC type sensor if temp is high then resistance goes down and by versa.

6th... try to look up ur fuel trims a little more advanced but look at the STFM & LTFM
using a PID capable scan tool. datastream scan tool.

if there is a negative sing before the number means the engine is running RICH and the ecu is taking fuel away and if you see a + sing before the number the engine is running LEAN and the ecu is adding fuel to compensate ..

if you need any specs on this sensors let me know i got access to ALL DATA in school

hope this helps


Modified by 96plusf20bb at 2:58 PM 4/13/2008


Modified by 96plusf20bb at 3:02 PM 4/13/2008