low idle when electrical load is added ( ELD disabled ?)

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socalsol
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low idle when electrical load is added ( ELD disabled ?)

Post by socalsol »

Hi all, This is my 1st post and I hope I can get some info on a nagging problem. When I turn on the lights (or any load) the engine bogs down to almost stalling. This problem occured after a new engine install and reprogramming my ECU. backgroung info: I have 2.0L GSR engine installed about six months ago. replacing an lsvtec engine. No change in wiring setup. No codes, no trouble indications - engine runs great. Using CHROME programming in my P28, same as previous engine - no problems before swap. Checked/double checked charging system/connections in detail and all is good. All key sensors and IACV were double checked - everythings checks good. I have been trouble shooting this problem for some months ( with friends ) and can't find the issue. My last guess is that during the break in tuning at a dyno shop ( used them before) the tuning session was terminated due to an oil leak near the end of that session and the ELD option was not set properly. I will find a shop that will read out the program setttings but its expensive for a session so I would like to get an opion if possible first. I don't do any programming myself but looking around on the web I noticed the ELD set option in CHROME and this could explain why the ECU is not compensating for an electrical load change. So could it be the ELD set/unset feature in the CHROME program? Any help would be appreciated!

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JaredKaragen
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Post by JaredKaragen »

Note battery voltage as you turn the lights on and off. It sounds more like an injector battery offset trim... Do you have oem injectors?
95 Sol Si : D16z6 : TD04H-13C 74 Civic 1200 : 100% Stock

socalsol
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Post by socalsol »

thanks for taking the time for the feed back. As far as alternator voltages go I will retest but the alternator/regulator are working and responding to a load - hence the engine loading. I did allot of probing voltages and cleaning contacts and I had the alternator rebuilt and bench load tested - before and after brush replacement - alternator works like a champ... I am using RC 440 injectors (2 yrs old) - the same setup as in the prior engine which did not have this load problem. Any other ideas??? Thanks in advance!

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JaredKaragen
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Post by JaredKaragen »

Sounds like injector battery offsets. I have to stress, you can tune a setup, then do something as trivial as move it to another vehicle, all same engine/induction/exhaust, and the tune will be off. Injector battery offsets amplify this issue. Hence this is why I charge a higher tuning fee on new car with same engine or new car new engine. I only give a lower price for same car same engine.
95 Sol Si : D16z6 : TD04H-13C 74 Civic 1200 : 100% Stock

socalsol
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Post by socalsol »

It's an interesting idea about being the set of fuel injectors. But I was able to dyno tune (via CHROME) with that set of injectors on the new engine so this injector set should have been tuned in to this engine, this was the dyno session that terminated early due to tranny oil leak but it got thru about 90% of the tuning session. So you think the idea of an unset ELD option in CHROME is not going to pan out? If what you are saying is the problem I will need to have it re-tuned? Thanks for your help!

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JaredKaragen
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Post by JaredKaragen »

socalsol wrote:It's an interesting idea about being the set of fuel injectors. But I was able to dyno tune (via CHROME) with that set of injectors on the new engine so this injector set should have been tuned in to this engine, this was the dyno session that terminated early due to tranny oil leak but it got thru about 90% of the tuning session. So you think the idea of an unset ELD option in CHROME is not going to pan out? If what you are saying is the problem I will need to have it re-tuned? Thanks for your help!
Sorry, I think I misunderstood the way it was written. You had it tuned... It has this problem? I would say it probably needs further tuning. The exact problem your having is indicative of not having the injector battery offsets tuned. The sod feature gives a slight rpm increase to go with the sensed load... But if it's killing your motor... That's not right. Plenty of other markets of hondas don't have an eld anyways... So really, it has to be tune. The fact that it ended early... Ya it sux, but the tuner should keep that in mind when it comes in for the retune. I do housecalls, so if they can get it fixed, I won't charge extra. If I'm waiting for hours, I'll charge a little extra, or if I fix it I'll charge my mechanic rate :)
95 Sol Si : D16z6 : TD04H-13C 74 Civic 1200 : 100% Stock

thething96
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Post by thething96 »

Not to thread jack, but........ I'm having a similar issue. I just did an F20b swap in my 95 Accord(I'll do a quick write up on the swap soon). When the car is under a load, the idle real low, and when the a/c is on, the car feels like it's going to die, like if the iacv or the ecu is not compensating for the a/c being turned on. I tried several different iacv's, but they all do the same. I used the original injectors, engine harness, throttle body, and other sensors. Using a P06 converted to vtec, street tuned. I didn't mess with the injector offset on the new engine because I'm using the same injectors. Also, the car ildes higher than what I set the tune for. I have the cal set to 800 rpm, and without an electrical load, the car idles around 950 rpm. Idle only decreases with a load. No vacuum leaks, all checked and tested, twice.
The sod feature gives a slight rpm increase to go with the sensed load... But if it's killing your motor... That's not right. Plenty of other markets of hondas don't have an eld anyways... So really, it has to be tune.
I thought that the injector calibration was for fuel values only????

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JaredKaragen
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Post by JaredKaragen »

Yes... But from a symptomatic diagnostic (no hard datalogs, or calibration available), it's pointing there. See; when voltage drops (uncorrected), it takes more time for the injectors to open, hence a leaner mixture off the bat. Now, depending on what your current offsets are set to, it could be a greater or lesser amount of time as voltage changes. This will cause stalling and bad behavior... Adjust your ac slider in ectune, fix your ac woes. Your base idle setting could be too low at the throttlebody, making your iacv \"run out of breath\" early. Plus the off-driving range of the maps creates problems because most are very hard to properly tune unless you have a braked dyno that can load based on engine rpm :). Pick a speed/rpm, lock it in, mess with pedal. Move to next rpm, lock in, mess with pedal. You get AMAZING fuel maps, but only if you keep conditions under close watch between levels.
95 Sol Si : D16z6 : TD04H-13C 74 Civic 1200 : 100% Stock

socalsol
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Post by socalsol »

Hi all, Thanks for all the input. I agree with JaredKaragen - it looks like something in the tune. I will schedule a dyno tune session next week or so and report back the results. thething96: youre problem sounds exactly like my problem - perhaps you also need a dyno tune. I will get back to everyone on the results of the tune and again thanks for all the help!

thething96
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Post by thething96 »

I street tuned my car, and idle afr's were set at 14.3 afr, and tuned the afr's with wideband. The problem with the ac idle slider is that no matter where I put the ac slider, it will now make a difference. -100 to 100, no matter what, idles does not move at all. I'm thinking that maybe there's an ac cable/switch that the ecu is not reading or noticing the ac being on, but I didn't move any ac cable or line, so nothing should have changed. I'll try the offset later today, and report back....

thething96
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Post by thething96 »

No luck................. No matter where I put the injector voltage at, idleing problems stay the same. I think that it might be a communication issue with the ecu and the iacv, maybe? Any thoughts?

socalsol
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Post by socalsol »

I would take a close look at the iacv. easy to take off, clean up, put 12v across the electrical connector and listen to it activating the valve. there is a test in place that works pretty good. while the engine is warming up just disconnect the electrical connection to the iacv and the idle should drop off - reconnect and the idle should pick up. I think thats the test out of the manual. I took mine off gave it a good cleaning and a bench test to rule out the iacv. perhaps you can try to set up a volt meter and look at the voltage at the wire connector side, if you have clips on your meterr it makes it easy to watch over the warm up phase. good luck

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Bindegal
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Post by Bindegal »

Don´t forget to look at the possible simple explanations also. Make absolutely sure that all engine/chassis/ECU ground wires are perfect. The old ground wires as well as their respective connections can get rusty, greasy or whatever over time. And you´d be surprised how much voltage drop can be seen over a 15 year old piece of rusty wire when under load. This causes all kinds of weird problems. I have solved complicated \"ECU\" or \"engine\" problems countless times by simply replacing ground wires and ensuring a good connection. Make sure both power-grounds are in good working order (one usually at the top of the engine, the other at the gearbox). Also take a good look at the ECU ground, usually connected near or at the thermostat housing. Sometimes even the resistance between thermostat housing and head can cause problems as people have the parts painted. /Allan
Regards, eCtune Team eCtune Authorized Tuner Location: Copenhagen, Denmark

thething96
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Post by thething96 »

I checked all the grounds, all are clean. Cleaned them up just in case. Ecu ground wire g101 was good, but regrounded it anyway. Added a couple more grounds just in case. Same deal. Checked all vacuum hoses, plugs, and sensors on the intake manifold, and everything is allright. The problem is that the engine is sucking too much air through the throttle body hole, the upper hole, for the iacv. Even with the iacv unplugged, the car sucks up too much air. Sometimes when driving, if left in gear, the car moves by itself, even without me giving it throttle. If I restrict the tb passage with my fingers, the car sounds good. I just reinstalled the f20b throttle, and the low idle issue is gone, but it's idling too high. Cold idle is real low. So far I used the f22b2 tb, f20b tb, 2 different iacvs, checked all vacuum lines and gaskets, datalogged and tuned, redid grounds( I have the honda schematics for grounds and plugs). Running out of options. Whats left on the to do list is, 3rd iacv, h23a1 tb( since I'm using the f20b intake, h23a1 plenum, f20b tb or f22b2 tb) and plenum gaskets. Thats all I've got???????

thething96
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Post by thething96 »

Problem solved !!!!!! After all these headaches, as always, ended up being something stupid and insignificant. It was the stupid starting idle valve!!!!! Its the little valve on the driver side of the plenum. That thing had an internal leak of some sort. The car was only acting up when I gave it low throttle, or when the ac was on, or high electrical load. I plugged the valve, an that did it!!! Thanks a lot for all the input from all you guys. An th the op, good luck with your setup.

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