Zetec Throttle Bodies Hard to Start?

[Al N.]

http://www.usa7s.com/aspnetforum/images/emoticons/hurray.gif

 

It was warmish and sunny today, so I decided to give it the old college try again. I did use the Pyroil starting spray and on my second attempt got the car to catch and stay running (with the aforementioned semi-delicate feathering of the throttle).

 

 

 

At first it felt like the engine was firing on 3 cylinders, literally. But then a few "pop-pop-pops" out the side exit and the old Zetec that I know and love was back. So I went out for a about an hour-long blat and reconnected with everything we love about these little cars. Thankfully, there is no "but" to the story.

 

 

 

John K - I am 100% mac-based, so doing my own ECU tuning isn't as easy as it is for some of your PC-based folks. However, I will try and borrow a laptop sometime this year to sit down and do exactly as you say.

 

 

 

Thanks again everyone for your suggestions and patience with my ignorant "does Al even know a thing about these cars" questions!!!Al Navarro2007-03-24 11:04:17

[JohnK]

Al,

 

HooRah - another wise soul who avoids Micro$oft - unfortunately one does work at the mercy of the software developers.

 

You don't have to be any kind of a wizard (my training is as a Biologist) to understand how to make your car run well, but it does take a bit of thought and some patience. The computer gives you so much control and makes it so easy to make and observe change, it's actually easier than in the 'good old days'. Me looking back 40 years trying to get my Ducati running and still mystified as to how that old DelOrto worked. Pushed that @#$% motorcycle all over the neighbourhood.

 

I will make a pretty confident guess that all you need to do is find the table that says that it's what the engine reads when the engine's below running temp and bump up the amount of fuel that it delivers in that state. Spitting back out the carbs is typically a sign the engine's not getting enough fuel. The worst you can do here is foul a set of plugs, and from what I've seen, that's not all that likely. Best of luck - at least your Se7en's running - I've got another year or so before mine will be ready to go. Enjoy the Spring and its weather.

 

Cheers,

 

John K

 

 

 

 

 

 

 

 

 

 

 

>>John K - I am 100% mac-based, so doing my own ECU tuning isn't as easy as it is for some of your PC-based folks. However, I will try and borrow a laptop sometime this year to sit down and do exactly as you say.

[slngsht]

>Clicky

 

 

 

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I have a Pectel T2 with Jenveys on my zetec. It was programmed some years ago but starts reliably, although it often takes two tries when cold here in San Diego; cold being relative(!). As I recall we set it to give extra gas @ the 500 RPM level and also advanced the timing some to prevent stalling/dieing. The map has a noticeables spike @ the 500 and 1000 RPM levels. Some experimentation should produce a better solution. If I find the map I'll provide more flesh on these rather vague guidelines.

 

 

 

Marren Fuel injection has helped some of us figure out what injectors to use. Tim Marren can be found on the internet and is located in NJ, I think.

[slngsht]

 

 

 

Marren Fuel injection has helped some of us figure out what injectors to use. Tim Marren can be found on the internet and is located in NJ, I think.

 

 

 

Holy Cow!

 

 

 

Tim Marren!

 

 

 

I bought some injectors from him in the early 90s. I can't remember what I had for breakfast. I don't know why I remember that http://www.usa7s.com/aspnetforum/images/emoticons/willy_nilly.gif

[Al N.]

The new SOP for starting my car cold:

 

1. Turn key so "accessories/ancillaries" are activated (including fuel pump).

 

2. Repeat 3 times.

 

3. Give throttle one squeeze, then release.

 

4. Turn key all the way to engage starter motor with light throttle pressure.

 

This has pretty much been my fix for the cold start problem since I came back from the Dragon. Works 80% of the time. The other 20% require just a little more coaxing. Still have not remapped ECU. Will wait until I do the head work.

[SR27.Seth]

I will make a pretty confident guess that all you need to do is find the table that says that it's what the engine reads when the engine's below running temp and bump up the amount of fuel that it delivers in that state. Spitting back out the carbs is typically a sign the engine's not getting enough fuel.

.

 

I think I would look at what information the ECU is reading before trying to change cold start maps. EG: Does the resistance in the coolant temp sensor (measured at the ECU) match the spec? Go through all of your sensors (computer inputs) and compare readings (be it voltage signal, wave, or resistance) to a reference, before you try to change any mapping. Remember an ECU is only a computer: GIGO.

 

 

 

 

[ottocycle]

Al,

I just read your post. I think your cold start (choke) map needs adjusting. It should be a little easier to do than idle, midrange or top end adjustments as it need not be too precise. It is only needed to ease initial ignition and will be bypassed when the engine heats up. Your existing map will take over once a certain temp is reached. When you get it remapped after you do the headwork tell them and they will bump up the values. Try and find a shop who have worked with your system. While the principles are the same for all programmable systems, you do not need to pay the tech guy to learn the details of your system. If you know who markets your system in the U.S. they might be able to steer you to a dyno facility near you. Remember a dyno is only a tool/gauge. It is only as good as its operator/interpreter.

Cheers,

 

Dermot.

[gjslutz]

I would think the back fire would indicate lean mixture. That along with the fact you need to hold higher RPM till warmed up would make me think that. My Zetec with the Emerald ECU and Raceline TB’s has no cold problems, although it has only seen 40’ during the time I owned it this past month. If you are uncomfortable with adding fuel, you could try to hand choke (reduce the air) into the TB on starting cold. Anything to block the air should work. Then as above it would be the ECU problem to solve.

Gary

[gjslutz]

Al,

 

Now have been starting up mine in the low to mid 30's. At times if I don't touch the gas Pedal it will start & die the first time. At times it will also do a lean pop (backfire) on starting. It idles smooth after 15 seconds after starting.

 

Gary

[Kitcat]

Start & die? Never had that problem with my Crossflow:).

[JBH]

At 25 F, my car would not start. It would catch briefly then die. It did this until the battery ran down. I borrowed a battery and then it wouldn't even catch. We tried choking it, ether, etc. I pulled the plugs to find a lot of carbon. I changed the plugs and it started, albeit reluctantly. By now it was 42 F.

 

I have tried Al's procedure, but it makes no difference. Temperature makes a big difference - it has to be fuel vapor pressure - indicating my startup map is too lean.