hot start
06-22-07, 04:15 PM
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Don't hate my V8
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hot start
on a post a while ago i saw a thing were you could put some resitors or somthign onto the harness to fix/overide the hot start system. i am helping afriend with a 86 NA and it has a hot start problem (go figure) but anywho all the help is, well helpfull.
thanks again
thanks again
06-23-07, 09:12 PM
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1. Make a fuel cut switch. Cheap and fairly effective but has drawbacks.
2. Install a switch that will break the circuit on the blue/black wire on 3B of the ECU. Have the switch *make* the circuit when the engine is cool/cold and at at any other time have the switch *open* so the circuit on pin 3B will be complete. In other words, when the engine is cold let the ECU see the START signal. Once the engine is hot, do not let the ECU see the Start signal. This should be more effective BUT still requires driver input.
3. Buy and build a simple Voltage switch (I bought one from JAYCAR) and have the voltage of the water thermo switch open the circuit to pin 3B once the engine gets up to over 120 degrees. Doing it this way requires no driver input at all.
2. Install a switch that will break the circuit on the blue/black wire on 3B of the ECU. Have the switch *make* the circuit when the engine is cool/cold and at at any other time have the switch *open* so the circuit on pin 3B will be complete. In other words, when the engine is cold let the ECU see the START signal. Once the engine is hot, do not let the ECU see the Start signal. This should be more effective BUT still requires driver input.
3. Buy and build a simple Voltage switch (I bought one from JAYCAR) and have the voltage of the water thermo switch open the circuit to pin 3B once the engine gets up to over 120 degrees. Doing it this way requires no driver input at all.
06-23-07, 09:20 PM
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Look at the Blue/Black wire in the jpg in this thread: https://www.rx7club.com/forum/showthread.php?t=664427
That is the wire at pin 3B that is the START signal to the ECU. It only has voltage on it when the key is held to START. If the wire is disconnected from the ECU, then the ECU does not see the start signal which in turn means the ECU START MAP will not be used during starting. The ECU will use the afm signal instead, and what this means is LESS fuel will be injected when you try to start the engine. Less fuel means the sucker won't flood. The downside to having this wire disconnected, is that when you do a COLD engine start there will not be enough fuel injected and the cold start will happen, but a lot of cranking will be involved. That's why a simple voltage switch activated by the water thermosensor to open/break the circuit on 3B is better/best.
The fuel cut switch or a switch to open/make the wire on pin 3B, will both do the same job, but not as well.
That is the wire at pin 3B that is the START signal to the ECU. It only has voltage on it when the key is held to START. If the wire is disconnected from the ECU, then the ECU does not see the start signal which in turn means the ECU START MAP will not be used during starting. The ECU will use the afm signal instead, and what this means is LESS fuel will be injected when you try to start the engine. Less fuel means the sucker won't flood. The downside to having this wire disconnected, is that when you do a COLD engine start there will not be enough fuel injected and the cold start will happen, but a lot of cranking will be involved. That's why a simple voltage switch activated by the water thermosensor to open/break the circuit on 3B is better/best.
The fuel cut switch or a switch to open/make the wire on pin 3B, will both do the same job, but not as well.
06-24-07, 06:22 AM
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In fact, go back and read that thread I posted above. Read the latest by AUGIEDOGGIE about HIS results of installing a switch to open/make the black/blue wire at 3B.
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06-24-07, 05:01 PM
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Don't hate my V8
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the start sequence omit works great, we just got done puting it on that 86 and it fires up after a lil role'n. some one sould make that hot start thinger a sticky
06-24-07, 06:14 PM
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If I had a HOT START problem, I would PM JRAT endlessly day and night. He knows all about this remedy and would like to talk to just about any number of people about it. JRAT likes PM's. After all, just imagine how hot that 10 second turboII of his gets, plus his wife's TurboIi is a pretty hot car too. PM the Rat.
06-24-07, 06:17 PM
#11
If I had a HOT START problem, I would PM JRAT endlessly day and night. He knows all about this remedy and would like to talk to just about any number of people about it. JRAT likes PM's. After all, just imagine how hot that 10 second turboII of his gets, plus his wife's TurboIi is a pretty hot car too. PM the Rat.
LOL!! You funny!
All kidding aside though, thats a pretty cool thing I never knew about the FC. Ya know, being on a haltech and all, I really never run into hot start issues..
06-24-07, 06:36 PM
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Some of us can't afford those new engines you have. humor
Attached is a jpg out of the Training Manual that NZConvertible made available a couple of years ago. The chart in the jpg will help anybody realize how if the Start Map is bypassed during hot start, the afm will THEN be the player and will inject much less fuel during start than the Start Map will. I've measured the amount of fuel using the Map and then using just the afm signal. It's a very large difference in the amount of fuel injected during Start.
07-01-07, 09:38 PM
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Just some follow up. I looked at the POCKETLOGGER site the other day and noticed something new in the RTEK2.0. The firmware for the RTEK2.0 has changed in version 1.1. In that version they give you the ability to select the amount of fuel during starting. Called Cranking amount I think.
That is superior to the version 1.0 where they had the fuel cut during starting by holding the pedal down all the way like on a stock series five. I never liked the idea of spinning an engine around and around with nothing but residue fuel to lubricate the rotor housings.
Just FYI for series four cars with hot start problems.
That is superior to the version 1.0 where they had the fuel cut during starting by holding the pedal down all the way like on a stock series five. I never liked the idea of spinning an engine around and around with nothing but residue fuel to lubricate the rotor housings.
Just FYI for series four cars with hot start problems.
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