Al N. Posted February 26, 2007 Share Posted February 26, 2007 My car has always been a recalcitrant cold starter. Once it's up and running, it's easy to restart. But from cold (and this weekend it was plenty cold) it was near impossible. I have an external fuel pump that I hear whir when I turn the key 1/4 turn...leave it there until the whirring stops (I assume that's when system is pressurized), then turn the next 1/4 turn. Anyone else with a similar setup have similar issue? (I wouldn't call it a problem, just a nusiance.)Al Navarro2007-02-26 12:01:26 Link to comment Share on other sites More sharing options...
Boxologist Posted February 26, 2007 Share Posted February 26, 2007 not on throttle bodies, but the 7 started fine on saturday night. my fuel pump is constantly audible till i start letting the engine and exhaust take over noise duties! http://www.usa7s.com/aspnetforum/images/emoticons/hurray.gif Link to comment Share on other sites More sharing options...
slngsht Posted February 26, 2007 Share Posted February 26, 2007 Al, from what I remember at Skyline, it takes a couple of minutes for it to act normal, right? Link to comment Share on other sites More sharing options...
RDROCKT Posted February 26, 2007 Share Posted February 26, 2007 Al, Most stock ECUs will turn on the fuel pump for a certain cycle and then shut it off. It does this as a safety function in the stock calibration. This does not signify that the system is pressurized, only that the time has elapsed. When you take the engine out of it's factory atmosphere and install a tank and pump without an anti-drainback valve (foot valve?), it may take more than a short run for the pump to actually pressurize the system. Try turning the key on until the pump stops running several times to assure the system IS likely to be pressurized. THEN turn it over. My $.02! Ask me how I know! Chuck Link to comment Share on other sites More sharing options...
slngsht Posted February 26, 2007 Share Posted February 26, 2007 I'd tell you to try something, but it's not the safest thing to try http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif If you swing your seven down this way, i'll try and see if that'll cure it. Link to comment Share on other sites More sharing options...
JohnCh Posted February 26, 2007 Share Posted February 26, 2007 Al, Sounds like a mapping issue. What ECU are you using? -John Link to comment Share on other sites More sharing options...
Al N. Posted February 27, 2007 Author Share Posted February 27, 2007 Thanks for the feedback everyone. Mazda-You are correct sir. I generally have to sit in the car and keep the revs up around 3000 for a little while before it will hold its own idle down around 1000 RPM. Does your unsafe solution include shooting raw fuel into the trumpets? Chuck-I will try that little trick the next time. John-I've got the PecTel unit. Oh, one thing I forgot to mention is that very occasionally, I get a backfire when starting. Perhaps I am flooding the engine a tad after the first non-start? Link to comment Share on other sites More sharing options...
slngsht Posted February 27, 2007 Share Posted February 27, 2007 Al, I think Chuck's fix would've addressed if your startup problem was very short. Yes, my unsafe solution involves shooting raw fuel... but, instead of carb cleaner or something like that, I shoot a slight amount of propane in... although if you have multiple trumpets, that'll be hard to do. Propane is already a gas, so it mixes in well. If your engine speeds up momentarily when you shoot it in, then you're not getting enough fuel. Link to comment Share on other sites More sharing options...
JohnCh Posted February 28, 2007 Share Posted February 28, 2007 A few more questions. Has the car had this problem from the beginning or is this something that has grown progressively worse over time? Is the cold start okay if the air temps are high, or is it a reluctant starter even on warm summer days? If it is okay when the weather is nice, was your car originally setup in a warmer climate than where you now live? Thanks, John Link to comment Share on other sites More sharing options...
Al N. Posted February 28, 2007 Author Share Posted February 28, 2007 It's always been somewhat reluctant. But it MUCH easier to get it running in the summer than now (temp in NJ in mid 30s) Link to comment Share on other sites More sharing options...
JohnCh Posted February 28, 2007 Share Posted February 28, 2007 My money is on a mapping issue. Cold start is a pain to tune correctly since you really only get one chance per day to make a change and then see if you made things better or worse. I am not familiar with the PecTel, but the Emerald uses a startup enrichment table that affects the timing and fueling based on temperature. My guess is that your system has something similar. You may need to change that, or it could require getting into your main fuel or timing table, or altering the throttle position at idle, or your startup timing, or a combination of the above (like I said, this can be a pain to track down). Hopefully someone with PecTel experience will chime in. -John Link to comment Share on other sites More sharing options...
slngsht Posted February 28, 2007 Share Posted February 28, 2007 I wonder what the maximum duty cycle of your injectors are. It is possible your injectors are oversized, and under cold start your fuel pools. Just a hunch. Do you know what size injectors you are running and how they compare to others with the same engine? Link to comment Share on other sites More sharing options...
Al N. Posted February 28, 2007 Author Share Posted February 28, 2007 You know Mazda, that's the $20,000 question...I know that there was some issue with injector sizing on some of the Caterhams early in the Zetec program. I've always wondered if mine was one, but never followed through on pulling the injectors. It would be great if someone with a similar set up could chime in...let me know what kind of injectors I should have, before I go through the trouble of pulling one to see what size they are. Anyone? Anyone? Bueller? Link to comment Share on other sites More sharing options...
slomove Posted March 1, 2007 Share Posted March 1, 2007 You need this for Mazda's suggested test http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif http://www.holtsauto.com/products/112.jpeg Contains a lot of diethyl ether and raises an engine from the dead at arctic temperatures. But I am not sure if you can buy this (or the similar Holts Start Pilot) in the U.S. And if you get too frustrated you can sniff it for a good night's sleep http://www.usa7s.com/aspnetforum/images/emoticons/ack2.gif Gertslomove2007-02-28 19:48:28 Link to comment Share on other sites More sharing options...
Al N. Posted March 19, 2007 Author Share Posted March 19, 2007 Is that ether based starting fluid bad for the Mass Airflow Sensor? And should I spray it into the trumpets or just on the foam filter (if this is the stupidest question ever, feel free to beat me)? I was going to try it this past weekend, but the weather prevented me from even getting the car out of the garage...I had to make about 6 passes with my snow plow to get the frozen sleet cleared from our driveway...then I did my neighbors' drives out of courtesy (it was pretty much near unshovelable in our neck of the woods...like shoveling sand). Link to comment Share on other sites More sharing options...
yellowss7 Posted March 19, 2007 Share Posted March 19, 2007 Al, I don't have a zetec, but I do have the Jenvey Throttle bodies and I find that to start mine up, I do the same with the fuel pump, wait until it stops, then when I turn the key I lighly feather the gas pedal to help it fire up. Has worked well for the past 7 years and I'm still on the orignial banner battery, and with a 12.4:1 compression ratio that's saying something! (I plan to get it out on Thursday or Friday as the weather forcast looks promising. I hope the 2 foot drift in front of my garage bay melts by then) Tom Link to comment Share on other sites More sharing options...
slomove Posted March 19, 2007 Share Posted March 19, 2007 Is that ether based starting fluid bad for the Mass Airflow Sensor? And should I spray it into the trumpets or just on the foam filter (if this is the stupidest question ever, feel free to beat me)? Directly into the trumpets. Obviously tricky if you have 4 of them. I suspect if you spray it onto the foam filter you will just wash out the filter oil and possibly cause a nice explosion in the filter (happened to me last weekend with a big bang and a plume of smoke just from the fresh spray of filter oil). Link to comment Share on other sites More sharing options...
JohnCh Posted March 19, 2007 Share Posted March 19, 2007 Al, Don't worry about damaging your Mass Airflow Sensor -- you don't have one http://www.usa7s.com/aspnetforum/images/emoticons/wink5.gif You are either running a Throttle Position Sensor (most likely) and/or a a Manifold Absolute Pressure Sensor with the Jenveys. -John Link to comment Share on other sites More sharing options...
Al N. Posted March 20, 2007 Author Share Posted March 20, 2007 Tom: the throttle feathering has generally been the case with my car. However, when it's been sitting cold, it's not so easy. Gert: I've had those little back fires on start up before. I think it may be due to fact that I apply a little throttle on start up (see above) and there's a bit too much fuel when the spark goes. John: Thanks for reminding me. I'm pretty sure I have the TPS set up. THANKS ALL! IF it's warm enough this weekend, I'll roll her out and try the ether spray (Pyroil brand). If it fails, I'll try the ether on myself. http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gifAl Navarro2007-03-20 06:14:07 Link to comment Share on other sites More sharing options...
JohnK Posted March 24, 2007 Share Posted March 24, 2007 Al, Learn your ECU, and what your engine expects. There should be a setup instruction for your throttle bodies from the mfg. This part of tuning is mechanical and, within limits, affects mostly low RPM takeoff. Things have to be really awry here to cause significant problems. The Bosch Automotive Handbook, 5th ed or so, provides a wealth of information in areas areas of ECUs and how engines work. I don't know how many models Pectel makes, but the one I've worked with has a cursor that shows you where you are in any map (spark, fuel, start fuel enrichment, . . .) real time, so you can see and try some things to experiments with what's happening re fuel. If you're not making black smoke when the engine's cold, you're probably pretty lean. You can't hurt your engine by running too rich, although it may cost you a few sets of spark plugs. (the tuner's golden rule: start out rich, plugs are cheaper than pistons) With the flash memory that the Pectel has, you update your calibration as you make changes (read the screen on the laptop and the instruction manual - online help may be sufficient). The work req'd to learn about this is well worth the effort. Without pulling teeth, I got a big lug of a 427 aluminum engine to start cold (40 F) with very little throttle and it would tick over at low RPM - and settle down to a nice idle once warm. It's not rocket science or brain surgery but takes a bit of study. For getting power, THAT is a lot of work and needs a dyno. Cheers, John K Link to comment Share on other sites More sharing options...
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