Early thoughts on CB fuel injection

I took my IM for its first drive after bringing it home last weekend. CB's system doesn't have 'cold start' feature, so starting her up was a chore (outside temperature was 2 or 3 degrees below freezing). About the same as starting her up with carbs. It took two or three minutes of feathering the throttle until the engine would idle on its own. It took another five to ten minutes of warming her up before I could pull away from a stop without stalling the engine. Once I finally got going she ran fine, except for a slight, light throttle bog off idle.
Henry spent some time working on the fuel injection, with input from Pat at CB, but more fine tuning is definitely needed.

Highly UNACCEPTABLE !!!

Even the Bosch OEM FI has a CHT for cold running ...

(are you supposed to live with this for 11 months a year ??)

Ron, if you install a hand throttle like I did, you can keep it running that way. My hand throttle on my dual 44 IDFs worked fine today, at 30 F.

Unacceptable in the age of FI.
The CB lack of flexibility (and cost) is one of the reasons I decided on Megasquirt

I bought a head temp sensor from CB and installed it in the boss at #3 in the 043 head. It is a thermistor and mounts via 1/8 NPT.
This is separate from the CHT gauge (thermocouple) which feeds a VDO gauge on the dash. Maegasquirt cannot measure a thermocouple.

The Megasquirt ECU then will use the CB temp sensor to vary the injection until warmed up.

I also have an intake air temp sensor in the aircleaner to compensate for changes in air density

FI with no cold start? Oh fer the luv o'Mike...

angela

When I purchased the kit I didn't even think to check if it had a 'cold start' feature. I automatically thought it would.
I'm not impressed with with this kit-a 'thumbs down' from me.

I doubt I would have asked either, Ron. But now you can definately bet that would be something I would ask...

I'm just flabbergasted that it was made that way. Makes me wonder what its doing for altitude compensation, if there's a knock senseing feature, etc.

Many fine years ago, I had an early FI system made by a now defunct company called Air Research. It was cool in that it was very easily adjustable, but was otherwise pretty crude. It did have a cold start feature that used a cooling system sensor to read when to enrich the mixture. Bear in mind that was circa 1985 or 1986...

This is 2010. We're like, not even in that century any more...

angela

What's a "cold start feature"? Speaking from Weber experience, isn't cold start when you pump the gas five or six times and hope like hell it fires?

Does cold start also include restarting the engine a few times until it actually decides to sorta idle as long as you keep your foot pumping on the pedal?

Cold start feature - what a neat idea!!!!

On the carbed 911's, build fuel pressure, crank til it catches, hold it at 1700 to 2,000 until the RPM picks up on it's own (2 minutes to 3 or 4 if it's really cold). Then it's all done. Do it that way, you won't foul plugs either. But those are different engines, most importantly, different oiling systems. I don't know if it's safe to start at T1 or TIV the same way.

On da chebby's, I always buy da carb wid da choke. It works real good.

angela

I think with an FI there is no pumping the throttle since it will not squirt any gasoline. That surely is a PITA. Keep us posted, hopefully Pat & Henry will find a solution for the cold starting which should be a standard feature on any FI system.

Eddy

In my 1.8T Audi Roadster I just reach in and turn the key. Start. Every time. Maybe it's because the car has BeeHIves.

Regarding cold starting and a dependable idle circuit, there is absolutely no substitute for beehives. I believe it was Vince said it first.

I ran my car on Saturday (FI Subaru)before putting it up for the winter. Mid 20's started up idled good but still needed a few minutes to warm up before there was good power form a dead stop. I

Dale,

Your such a p---y! That was funny though.......;-)

Ron sorry for the issue. That is a bummer. Minus temps? Burrrrrrr

Angela speaks the truth. I can hear the fuel pump change tone and I know the float bowls are full. Two squirts of fuel and my baby is running. I love Webers if they are set up right. Mine are a bit fat now because of the cold weather but I don't mind burning extra dead dinosaurs and corn.

You know, life would have been SO MUCH easier if these Webers and Dellortos simply came with choke plates.

Every EFI engine I've ever played with simply started by just turning the key. No futzing with the gas pedal or anything - just turn the key and it starts and runs smoothly, no matter what the outside temps. I guess that's why my son likes EFI and hates any carb ever made (therefore, he also hates most of his outdoor power equipment for that reason). He and his friends are also fans of Megasquirt systems for off-builds, although many of them run re-programmed Mitsubishi systems.

The other side of the cold-start EFI coin is, however, my diesel truck. It's very grumpy when cold (below 40 degrees...it's a truck raised in the South!) I have to hit the glow plugs twice (10-15 seconds each time) and then hit start (never touch the pedal). Then it doesn't so much as start as sort-of grudgingly wakes up, grumbles and stumbles a bit, belches a big cloud of blue smoke and then smooths out. Kind of entertaining, actually, and way more dramatic than Pearl has ever been. Once it's started that first time in the morning it's well mannered for the rest of the day. I've also found it beneficial to make a run to Jacksonville at 80+ once a month to keep it cleaned out. It likes that.....

webers to have a 'choke' so to speak, but most people just remove them. it's essentially fuel enrichment.

I took the IM out for another drive. It was warmer today, and she idled after only a few minutes. Still a PITA, but it's something I'll have to live with.
Once warmed up she's a joy to drive. Just for the hell of it, I slowed down to 2200 rpm, in fourth gear, and when I pressed down on the gas pedal she picked up speed smoothly, without a hick-up.

NICE!!

I guess that should be hiccup.....

Ron, Our efi does have cold start. What it doesn't have is an IAC valve or "idle air control valve. The reason is dual throttle body engines and dual carb engines have very little vacuum at idle. All an IAC valve is is a giant vacumm leak that raises the idle at start up and slowly lowers it based on engine temp. The problem is that the IAC valve uses all the vacuum that the map sensor needs to control idle air fuel ratio. We are working on getting an IAC valve to work with the dual throttle body efi kits. I have already talked to Henry and will keep him posted on my progress.
Pat Downs

I have just bougth this EFI from CB, but my car is a summercar. I dont need the chokefunction. I hope this EFI is better than weber 48 IDF.

Pat ; will this http://www.cbperformance.com/catalog.asp?ProductID=1855
work with this EFI.

is Norway warmer than Kanada ?

(Just "fjordin" wid ya ).

Pat, thanks for the update. A fix would be greatly appreciated!
Morten, the first time I drove my IM it was warm enough to have the top down, but the engine still needed 3-5 minutes of high-speed idling before it could be driven without stalling.

I am now installing this on my new build engine

Pat,

Does the CB kit have an engine temp sensor? If so forget the Idle Air control valve and just build it into the fuel and timing curve. I've worked with one of the other high end fuel injection kits for some time now and it works great without one. It's all in the mapping.....

My car is running very rich, and I smell like a gasstation after 15 min. Do I have too adjust the AFR myself ? or will this selftune ??

http://www.forum.vwacb.com/index.php?topic=2639.315

Morten, I had a similar problem with mine. Before my four day cruise (I'm on day two) I hooked my laptop up to my fuel injection and adjusted my air/fuel ratio to around 12.5/1. There is still some smell, but the engine is not running rich.
Next is my warm start problem. If I stop the car for a short time (such as stopping for gas) the car is very difficult to start. I've played with the hot start fuel/air ratio, but I'm not there yet.

Hey Ron,

Sorry to hear that you are still having problem with the CB EFI. It almost sounds like It is better with carburetor. I hope you'll get this tune soon as summer is close coming to an end at your end.

Eddy

Eddy, that thought has crossed my mind.
As I mentioned in another thread I just completed a 1100 mile road trip in my IM. The car ran extremely well, except for my CB fuel injection. The car has always been hard to start when hot and this got progressively worse on my four day cruise. On the last leg of my trip the engine would stall when I came to a stop and I had a heck of a time getting it going again.
Note that the engine shroud etc, was so hot I couldn't rest my hand on anything for more than a second or two (but my oil temperature was 180 degrees and my head temperature was around 200 degrees).
My fuel pressure regulator is located in the engine compartment and this may be a big part of the problem. CB's instructions states that the fuel regulator should not be installed in the engine compartment, but that's where Henry installed mine. When the engine is cold the car starts easily and runs fine, but after a half an hour or so of driving if I turn the engine off for 5 minutes the car is very hard to start. If I wait 15 to 20 minutes it starts fine.
I'm thinking the hot engine compartment may be affecting my fuel pressure regulator, creating something like a vapor lock. When I get the car started I can rev it to 3000 rpm, but the engine will die, like it's not getting any fuel.
I plan on fabricating something so I can keep my engine lid open 4 or 5 inches. Hopefully, this will keep the engine compartment temperatures down and help my hot start problem.
If this does work my winter project will be to move the fuel regulator to another (cooler) spot.
Morten, where did you install your fuel pressure regulator?

how sealed is your engine bay? Where is the intake for the fan? i see lots of folks put it through the 'firewall', but IMO that just sucks up hot manifold air from #1-2.

a fan shroud too hot to touch seems wrong.

considered Megasquirt? LOL

also - not that you asked me, but i put my FPR above my tranny

Ron,
easy fix for a hood prop.

Terry, I installed something very similar today. Road test this weekend.
Mango, thanks for the info. I will definitely move my fuel regulator this winter.

Hey Mango,

Do you use EFI? I thought I used to be able to see your specs on your web site, but now it looks like the link is no longer available and all I can see are the pictures.

Eddy

ya - i was wondering where they went too. LOL

i moved to google sites and i guess i lost the webpage. i still have the specs. email me if you have a specific q i can help with. :)

i don't have efi, but i have electronic ignition (laptop tunable / crank fired)

I'm a little curious about the "regulator can't be in the engine bay" thing. Why is that?

I'm curious because I'm putting an 85 911 engine in a car and the regulators are factory mounted on the engine. Not "in the bay" but actually on the engine. 2.0 Turbo subarus also have them mounted on the engine (actually fuel rails - but those are really ON the engine). Probably quite a few others too, those are just the things I've been messing with. Some of the subaru's have the regulator dang near UNDER the intake manifold.

For carbureted cars, we've been putting regulators in the engine bay's for years (with a return line to the fuel tank). No issues - but back on subject, we're talking about FI here.

So what am I missing here? I'm definately on the learning curve with this stuff, so if someone could share this info, I would appreciate it. Just not getting the "why not" part.

angela

Aaaah.... Good ol Google, Mango,I was wondering because your comment of the megasquirt. I still believe EFI is the best way and I am just reading as much as I can and trying to figure out who has a good install that does not cost an arm and a leg.

Eddy

Porsche 928's, as designed and built, have 3 regulators, all mounted on the engine.... although they call 2 of them "buffers". I don't think moving a regulator in or out of the engine compartment will either cause nor solve other problems...

You know what? The symptoms Ron is experiencing are CLASSIC pressure regulator failures. Especially the beyotch to start when the engine is hot (well that and leaky injectors).

Ron? I'll be that Pat has been talking with Henry about running a pressure test on your system. Probably have to do a running pressure test and "sitting" or residual test.

If it proves that your regulator has failed, and they do that sometimes, even new out of the box is possible, then you will probably also have to reset your fuel parameters as they were set, and then adjusted with a bad regulator.

I actually hope this is the case. Yes, it would be a pain to reset everything but DANG, this should run much better than it does. It would be a great bit of resolution to solve it.

angela

Oh another thing - this is just throwing it out there.

FI is real picky about voltage drops. Even a couple of tenths of a drop below optimal makes it lose signal and it wont' fire. So, for example, if your starter is pulling a little hard when the engine is warm (little bit of heat soak), you can get a voltage drop and the FI won't fire.

You can test measure the drops or you can do the redneck method of testing it. The redneck method is to drive the car until you experience the problem. Say it takes 30 minutes and shut it down. You go through the normal shenanigans to get it started and FINALLY it starts. Drive it a bit more and then shut it down on a hill. Try roll starting it. If it fires quick, you're onto something.

angela