DSM Injectors, Resistor Boxes, and Hot Start Problems
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sorry my thoughts are all over the place but ive been thinking about this for the past couple days
Is it just me or are honda resistor boxes only 6 ohms? I was reading the helms manual on what normal resistance is on our injectors and its from 10-13ohms
I measured my dsm injectors and they read 2.3 ohms across the board meaning it would only reach a total of 8.3 ohms together. 6 + 2.3
Which is about 2 ohms less than normal.
When resistors get really hot do they get out of spec. ie. a 10 ohm resistor now provides 12 ohms of resistance when it gets hot.
I recently soldered some extension wires to the ends of a 10ohm 10 watt resistor from radioshack and afterwards measured the resistance. It read 15+ohms then slowly dropped as the resistor cooled off. The heat from the soldering iron transfered to the resistor and was warm to the touch.
In the engine bay after a car warms up im thinking the heat may throw the resistors way off spec > 13 ohms
After we shut off the car we cant start it again because resistance is too high for the injectors only when we let the car cool is it able to provide the right amount of resistance.
Does this sound way off???
Is it just me or are honda resistor boxes only 6 ohms? I was reading the helms manual on what normal resistance is on our injectors and its from 10-13ohms
I measured my dsm injectors and they read 2.3 ohms across the board meaning it would only reach a total of 8.3 ohms together. 6 + 2.3
Which is about 2 ohms less than normal.
When resistors get really hot do they get out of spec. ie. a 10 ohm resistor now provides 12 ohms of resistance when it gets hot.
I recently soldered some extension wires to the ends of a 10ohm 10 watt resistor from radioshack and afterwards measured the resistance. It read 15+ohms then slowly dropped as the resistor cooled off. The heat from the soldering iron transfered to the resistor and was warm to the touch.
In the engine bay after a car warms up im thinking the heat may throw the resistors way off spec > 13 ohms
After we shut off the car we cant start it again because resistance is too high for the injectors only when we let the car cool is it able to provide the right amount of resistance.
Does this sound way off???
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good point...maybe that's why people have a hard time with these injectors when starting the car.....i've heard of this on many occasions. The DSM's always sounded like a great alternative; cheap, abundant, and a standard bolt-up application. Maybe just sticking with RC would be the best approach. It just seems like some people have good experiences, and some just don't it's a 50/50 chance with these used injectors. Clean and Balancing would take care of flowing the right amount of fuel....but the low impedence and saturated seems to always be a problem.....
WADDUP Mark!....man I couldn't attend that meet...I was just to tired....sorry man
WADDUP Mark!....man I couldn't attend that meet...I was just to tired....sorry man
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Hey John long time no talk...
Too bad it was a pretty good meet. ill keep u updated next time
^^^ anyone??
Too bad it was a pretty good meet. ill keep u updated next time
^^^ anyone??
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I have the most problems with warm starts though. Hot starts and cold starts are fine. Anything between a few mins to a few hours after turning off the car takes at least a good 5 seconds to start.
By then the resistors should be cool again.
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#5
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by red_sir »</TD></TR><TR><TD CLASS="quote">I have the most problems with warm starts though. Hot starts and cold starts are fine. Anything between a few mins to a few hours after turning off the car takes at least a good 5 seconds to start.
By then the resistors should be cool again. </TD></TR></TABLE>
thats exactly what i was going to say
i'm glad this thread has come about though. any other suggestions/thoughts on this topic?
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thats exactly what i was going to say
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#6
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this is interesting and it make sense if this is the real cause. i'm also experiencing the hard starting when i restart the engine after just a few minutes but if i wait for a few hours then it will start fine.
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so u finally had time(or was it *****?) to post your thoughts on this huh allen? haha, j/p. nice write up
Modified by Racerage1 at 10:04 PM 6/11/2003
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Modified by Racerage1 at 10:04 PM 6/11/2003
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kinda weird....i have problems with cold starts.........hot starts my car fires right up
*shrugs*
*shrugs*
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 »</TD></TR><TR><TD CLASS="quote">
thats exactly what i was going to say
i'm glad this thread has come about though. any other suggestions/thoughts on this topic?</TD></TR></TABLE>
Heatsinks and fans could help. Lucky for us the personal computer industry mass produces cheap, effective, compact 12v examples for us... only costs a few bux to see if helps.
thats exactly what i was going to say
![](https://honda-tech.com/forums/images/smilies/emsad.gif)
Heatsinks and fans could help. Lucky for us the personal computer industry mass produces cheap, effective, compact 12v examples for us... only costs a few bux to see if helps.
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i guess i'm not convinced that its a resistance (or resistor heat) problem since mine starts perfect when its hot.
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 »</TD></TR><TR><TD CLASS="quote">i guess i'm not convinced that its a resistance (or resistor heat) problem since mine starts perfect when its hot.</TD></TR></TABLE>
Do you use the resistor box or do you use the 10 ohm 10 watt resistors from radioshack?
Do you use the resistor box or do you use the 10 ohm 10 watt resistors from radioshack?
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I had lots of problems with my dsm's. Like the car would start just fine and idle, but when i rev it like over 3k rpm it would start to flood the engine with fuel. There would be like cloud of black smoke out of the exhaust. I tried those radioshack resistors they didn't work then resistor box same thing then I just took them off before I mess something up. What do you guys think it could be.
#16
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by disguy409 »</TD></TR><TR><TD CLASS="quote">
Do you use the resistor box or do you use the 10 ohm 10 watt resistors from radioshack?</TD></TR></TABLE>
i have an OBD-0 car so it came with a resistor box.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">I had lots of problems with my dsm's. Like the car would start just fine and idle, but when i rev it like over 3k rpm it would start to flood the engine with fuel. There would be like cloud of black smoke out of the exhaust. I tried those radioshack resistors they didn't work then resistor box same thing then I just took them off before I mess something up. What do you guys think it could be.</TD></TR></TABLE>
sounds like a tuning issue to me.
Do you use the resistor box or do you use the 10 ohm 10 watt resistors from radioshack?</TD></TR></TABLE>
i have an OBD-0 car so it came with a resistor box.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">I had lots of problems with my dsm's. Like the car would start just fine and idle, but when i rev it like over 3k rpm it would start to flood the engine with fuel. There would be like cloud of black smoke out of the exhaust. I tried those radioshack resistors they didn't work then resistor box same thing then I just took them off before I mess something up. What do you guys think it could be.</TD></TR></TABLE>
sounds like a tuning issue to me.
#17
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 »</TD></TR><TR><TD CLASS="quote">
i guess i'm not convinced that its a resistance (or resistor heat) problem since mine starts perfect when its hot
</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 »</TD></TR><TR><TD CLASS="quote">
i have an OBD-0 car so it came with a resistor box.
</TD></TR></TABLE>
maybe that explain why you're not experiencing hot start problems. as Civtek, said the resistance of our injectors is 10-13ohms, so a 2.3ohm dsm injector with the 6ohm resistor pack equals 8.3ohms when it gets hot, resistance jumps to around 10-13ohms so it is still within ballpark. now couple that with the heatsink of the resistor box and the 10-13ohms become stable.
i guess i'm not convinced that its a resistance (or resistor heat) problem since mine starts perfect when its hot
</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by keebler65 »</TD></TR><TR><TD CLASS="quote">
i have an OBD-0 car so it came with a resistor box.
</TD></TR></TABLE>
maybe that explain why you're not experiencing hot start problems. as Civtek, said the resistance of our injectors is 10-13ohms, so a 2.3ohm dsm injector with the 6ohm resistor pack equals 8.3ohms when it gets hot, resistance jumps to around 10-13ohms so it is still within ballpark. now couple that with the heatsink of the resistor box and the 10-13ohms become stable.
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by red_sir »</TD></TR><TR><TD CLASS="quote">But I'm using the 10 watt 10 ohm resistors but I have warm start problems too. </TD></TR></TABLE>
so do i. i'm using 10w 10ohm also. so put the 10ohm with the 2.3ohm injector that'll be 12.3ohm but when the resistor heats up resistance will be higher probably around 14-15ohms.
so do i. i'm using 10w 10ohm also. so put the 10ohm with the 2.3ohm injector that'll be 12.3ohm but when the resistor heats up resistance will be higher probably around 14-15ohms.
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by _Endless_ »</TD></TR><TR><TD CLASS="quote">
so do i. i'm using 10w 10ohm also. so put the 10ohm with the 2.3ohm injector that'll be 12.3ohm but when the resistor heats up resistance will be higher probably around 14-15ohms.</TD></TR></TABLE>
But I don't have hot start problems... only warm ones like Keebler.
so do i. i'm using 10w 10ohm also. so put the 10ohm with the 2.3ohm injector that'll be 12.3ohm but when the resistor heats up resistance will be higher probably around 14-15ohms.</TD></TR></TABLE>
But I don't have hot start problems... only warm ones like Keebler.
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LEON »</TD></TR><TR><TD CLASS="quote">I'm not having any problems of any sorts, even after +1 year.
</TD></TR></TABLE>
Just wondering, are you using 1st or 2nd gen DSM injectors? What's your idle correction set at? Thanks.
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Just wondering, are you using 1st or 2nd gen DSM injectors? What's your idle correction set at? Thanks.
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