Air temperature hits 100 degrees and all hell breaks loose!

I understand your frustration concerning the oil temperature gauge but I think 220 degrees is typically viewed as hot but still o.k. on regular vw type 1 engines.  I don't know how the temperatures would affect fuel injectors, though.

When my gauge hit 210 I wonder what the REAL temperature was.

Ron

Ah - missed that part!

Electronic fuelie, is it? 'cause you might just have a hot box of silicon mussin' up your idle & such.

Sorry for your troubles; glad you made it home safe & sound.

Giday, Ron...sorry to hear of your troubles. If you get serious about converting to a Soob, I'd be happy to send you a list of components that I used. I've put just over 10,000 miles on my conversion (junkyard engine) and have no issues. I've been driving in temps over 40deg C lately. Rebuilt long blocks are available for around $2,500. I'm running a single Weber 32/36 carb and get about 39 miles to the US gallon on the highway. The offer is open to all for the parts list.

Was everything back to normal once the engine cooled down?

The engine stalled at anything under 2500 rpm, and once it started to stall no amount of feathering the gas pedal would stop the stall. The strange thing is when I finally pulled into my garage the engine decided to idle.  I have no idea why.

I don't plan I driving the car again anytime soon.  I've had serious hot drive-ability problems since new and I'm done with it.  I plan on phoning CB tomorrow to see if they have any solutions.  If none are forthcoming I'm pulling the engine this month and taking off the fuel injection kit.  I'll sell it for what I can and contact Art Thraen for a set of Dellortos or whatever he recommends.

The straw that broke the camel's back is when my wife told me, after today's drive, that she will no longer go for drives in the IM until I get it fixed.

David, I'll keep you in mind.  One of my options is converting to Subie power.

Ron

Heck, I totally rebuild the cooling system in my monster Miata, which included building a frame for a custom radiator.  Installing a front radiator in my IM couldn't be that much harder, could it?

Ron

I feel your pain, Ron.  I''m like you in this respect: I don't mind doing the research, whatever wrenching I'm capable of, and spending what it takes to get quality.  However, once I do my part, I want things to work.  At my stage in life, I don't have to cheap out like I did when I was much younger.  But, man, I get pissed when I buy quality and still have problems.  Hang in there, podna', better days are comin'.   

Ron O,I have to tell you that 220 is not "crazy hot" at all. I have hit that on a long freeway run,and it still purred like a kitten.

 I have a very good idea why your car is doing what it is doing. I have years of fuel injection experience and programming some stand alone systems. Every fuel injection system out there has a closed loop TEMPERATURE COMPENSATED fuel map. The colder a engine is,the more fuel the engine will need,and as it warms up the Fuel system computer will LEAN OUT the fuel mixture as TEMPERATURE RISES.

 That is fine when you have a liquid cooled,thermostatically controlled cooling system with fans to KEEP THE TEMPERATURES WITHIN A CERTAIN RANGE.

 But with a aircooled motor,having the temp sensor in the head,the head will get so hot,but it is not the "actual" temperature of the engine and your computer is totally leaning it out!!!

 You have to adjust the temperature comnpensating part of the Fuel injection map so it is the same at operating temperature as it is when it gets "real hot",otherwise your car will always do this. After you got the car to cool down,it ran normally due to the fuel being adequate with a cooler temp.

 You can also move the temperature sensor to somewhere else where it is not as hot as a cylinder head(I am assuming that is where your temp sensor is for the FI system)

 I have had this issue before when I started programming FI,and basically leveled out all the compensation values after a certain temperature.

 ANOTHER POINT OF CONSIDERATION IS....you more than likely have a AIR TEMP sensor in the FI system as well,THIS ALSO will lean out the air fuel mixture when it gets hot,since the computer "thinks" the ambient air is so hot (under your engine cover) that the air is less dense and will totally lean out the air fuel as well.

 Either learn to program the air/engine temp fuel compensation OR move the air temp sensor where it will not get so hot. The air temp sensor will generally have a greater effect onthe mixture than the engine temp sensor,so focus on that first. Good luck!  Or...get a dam set of Weber 44's!!   

I worked for Ford and this is what I specialised in . A couple questions, Ron what brand of EFI do you have ? I am a little confused by the post , are they using a ECT mounted to the heads for your temp reading ? If so why not just move it down to the sump in the oil ? I have seen some open loop systems, CB drag race system was open loop if I remember correctly, I am pretty sure closed loop is an option on some others. I prefer a closed loop system , especially with adaptive learning strategy ( learns how you drive and adapts to it) also a limp mode in case of system failure. James I know you have alot more experiance on aftermarket systems than I do but when the ECT has a failure it REALLY richens the mixture up( ECU sees this as VERY cold engine)  compared to an ACT. Ron I wouldn't give up on the F Injection , just try to find someone near you to help you set it up. If you cannot locate someone to help you email me and I will try to locate someone near you.Mike McCarthy

Ron:

In a word: yes. It COULD be that much harder. Certainly harder that bolting on a set of carbs. I'd put the subi thing out of my mind unless you want to not be running again until this time next year.

I'd get the nicest set of Dellortos I could find, send 'em to Art, bolt 'em on, sync 'em up, and be done dorking with it.

Is it perfect? No. Will it be a lot easier than even the easiest solution you are going to come up with on the EFI, as it is currently configured? Absolutely.

It doesn't take a year to do it, Stan and I can prove that. With what I learned on my Soob conversion, if I had all the parts on hand I could do the job easily in a month of spare time.

James and Mike, thanks for your input.  I just got off the phone with a fuel injection tech at CB (Mark) and they're going to look at, and possibly modify, an EFI profile I sent them last week.  When I get it back I'll install it and go for a drive with my laptop hooked up.  While driving I'll data log and send the file to CB.  Hopefully, they can come up with a fix.

Now that sounds like a plan, Mike

I humbly submit that, yes, it sounds like a plan. But (and I mean this sincerely), it sounds like the same plan you had when you first put this set-up on the engine. It hasn't worked right yet.

Why is this better than a set of carbs?

Me personally I have never owned a VW with Electronic Fuel Injection and have been absolutely happy with my carbs, but I do not mind tinkering to keep them running exactly the way I want them to. If I had the chance to make the change I would for the exact same reason, I like to tinker. Here is what I had on my drag car,

 the engine has been changed around since then and now is set up for the street for a new project and will be driven on the street, 366 rwhp. So I do like carbs. Mike

That's one helluva carb there, Mike!

Yeah, but what would be REALLY awesome would be if, instead of just bolting a single Predator to the turbo intake, he adapted an old 6-71blower to that (I know, belts would be hard) and then put a pair of big Holleys on top of the blower, plus some velocity stax or maybe a "bug catcher"-style scoop. Just, ya know, cuz.

There was a guy out in California who ran dual blowers with a 4 barrel on each, I rmember him flying , maybe you will like this vid. Sorry for jacking your thread.The guy nearest to the camera has a blown engine running nitro methane , the other is a turbo with nitros. BRE vs Paridise express.

http://www.youtube.com/watch?v=MFkUC_iGzNM

Mike McCarthy

Ron,

I'd really looking into fuel boiling as an issue for you.  Wasn't your fuel pump mounted in the bay?  For some reason, I thought it was and I believe I suggested moving it out.

You do have a fuel return line on that system, correct? 

It's not your oil temp that is making it run badly because your oil is hot, but not hot enough to cause the running issues you have. I'm really liking fuel boiling (early stage of vapor lock) for this.  I think it's causing a lean condition and affecting your idle and throttle response.  It's possible that FI system has the ability to read air temps and may be reacting badly to them (throwing it into an excessive lean condition) but really suspect fuel boiling.

One way to test this theory is to drive it today.  If it acts fine - you're onto the problem because you heat soaked the hell out of everything with the parade laps followed by shutting the car down.  Once you pass a tipping point on heat, you really have to let the car COMPLETELY cool (like overnight). 

angela

Angela, the fuel pump is by the fuel tank and I had Henry move the fuel regulator out of the engine compartment. 

It made no difference.

When I drove to the races in the morning the car ran fine.  The air temperature was in the low 80s.  The engine ran smoothly and had a steady idle.  I parked the car, went to watch some races, and came back two hours later to get in the lineup for the parade laps.  Right from the get-go she wouldn't idle and the stumble was back.  The air temperature was in the low 90s.

I think the 90+ degree temperature somehow caused the problem, but I'm not sure it's vapor lock.  My engine compartment lid was popped open four inches and the engine was quite warm, but not really hot.

This Spring I wrapped some of the fuel lines with heat tape (those that I could get at) and made sure there was no gaps around my engine tin.

Having said that, I'm not ruling out vapor lock, because it feels like the engine isn't getting enough fuel.  At anything under 3000 the engine starts to stall and no amount of pedal pumping changes anything.   The engine just dies.  It will start again, but only with A LOT of cranking with the gas pedal floored.

I have my new profile and I'll install it today.  Hopefully, it will be hot enough when I go for my test drive.

I plan on pulling the engine and transmission this winter to change the R&P from a 3.88 to a 3.44.  If my EFI problem is not solved I'll take it off and install a set of carbs.

Ron

Vacuum leaks can affect fuel/air ratio and timing if you've got vacuum advance. Made worse at idle due to high vacuum. Occurring when hot would make me think manifold (heat expansion), but check hoses too. Carb cleaner sprayed around any leaking joints/ports will raise the rpm a bit.

Throw a timing light on it and check that too. Is it advancing properly as you rev up and down? Mechanical advance sticking? Vacuum advance connected? Do you have good spark on all cylinders?

Could be a failing sensor, IAT, engine temp, O2. Does the CB system have any way to view the sensor values while running?

FWIW, I think Angela's on the right path. I also think your plan is logical, Ron-- one season is enough to lose on this problem. If it isn't resolved by spring, I'd go back to the last known successful point- and that would be a good set of carbs.

You'll have to educate me here. Only time I've vapor locked a carb car, it just sputtered and died when the bowl ran dry and wouldn't start again until it cooled off, and I've never had a FI car vapor lock. Shouldn't vapor lock make the engine run worse the higher you tried to rev it? Why would it run ok over 3000 RPM? No doubt rough running, useless throttle, and hard starting seem to be all indications of it, though.

Good point, Justin.

I got my revised profile from Mark (at CB) today, loaded it and when for a test drive.

I took along my wife and our laptop, so she could do some data logging if the EFI acted up.

It didn't.

I took the car out on the freeway and cruised along at 4200 to 4500 rpm for 15 or 20 minutes.  At 4500 rpm it didn't take long for the temperature gauge to creep up to 205/210.

At that rpm the car ran fine.  I took an exit and came to a stop.  The engine idled fine.  No problems.

So, is my EFI cured?  Maybe.

When I had my serious drive-ability problem on Sunday the outside temperature was 95+ degrees.  Today, the temperature was in the high 70s/low 80s.  The EFI seems to act up when the air temperature get high.

I'm not sure which car I'll take on my five day cruise.  I spent yesterday getting the Miata ready, and after today's test drive I think the IM might be okay to go too.

Ron that is great news!!! Mike

Fingers crossed for you, Ron!  You've really earned the stripes fiddling with this...

Just for the record, you can definately get fuel boil in an FI system.  It will be in the rail and is aggravated by ethanol based fuels.  Ethanol has a lower boiling point than standard gasoline so it more prone to this issue.  An FI system with a return line is less likely to suffer this (not all FI systems have return lines) though it is still possible.  An FI car with fuel boiling may run at WOT because of an enrichment circuit usually related to either engine vacuum or TP provides a bump in fuel pressure.  The added pressure can help compress the boiled fuel and give you liquid gasoline to run the engine , or if the system has a return line, will help push the boiled fuel out of the rail.

That said, I have no freakin' idea why Ron has had so many problems with this.  I would have long ago flipped out - he has the patience of a saint.

angela

I can see that being an explanation on a dead-head system with stagnant fuel in the rails. Wouldn't a return system start boiling fuel first at the low pressure point, the fuel pump inlet, due to the heated fuel in the tank? Then with the lack of pump pressure, I can see how the fuel could then start boiling at the rails due to the pressure drop. In that case, shouldn't the engine still have symptoms of inadequate fuel flow with the fuel pump sucking air even at high rpm?

The boiling temperature margin you'd gain increasing from 43psi to 57psi (more than a N/A vehicle is capable of) is only about 10* C (113* C to 122* C) for pure ethanol. Seems like that's a pretty small gap between preventing boiling and uncontrollable boiling for the pressure regulator to completely make up for it. Of course letting your fuel lines hit 250* F or more in the first place is another issue.

Where would my fuel line hit 250 degrees?

I am not trying to upset or embarass anyone but If the fuel gets hot enough to boil at the fuel pump inlet on a properly set up fuel system I would run away screaming " she's gonna blow "  , seriously though with pump gas and EFI and a properly set up fuel system there shouldn't be much of a chance of fuel vapor lock. Everyone on here can correct me but usually vapor lock happens on low pressure ( carb) set ups , the more fuel pressure the less likely it is to happen . How many factory FI cars with engine compartments running at 200 plus degrees F  have vapor lock problems ? With a return system it should be even less of a problem as fuel is constantly recycled. Ron has stated that after his new software update that the symptoms seem to have changed . It sounds to me like CB has it hands full trying to calibrate its  EFI system to all the potential combinations out here and I consider that NORMAL . Personally I wonder why they haven't gone to a Mass Air system yet instead of a MAP setup ? Seems to me it would be easier to set up a MAF fuel grid and make it more adaptive using it for all the potential combinations . I may be wrong but if I wanted to bolt something on and didn't have alot of patience or ability I would have built my engine around a single carb setup, second choice would have been a CFI ( single injector) setup. It appears that Ron has the knowlege and means to want more from his car than just transportation. I do Not consider his fuel injection setup as a bolt on and go system, but rather a tuners toy comparable to running dual 48 IDAs on the street. If I had the chance I would jump all over his setup but the cost for me stops that from happening. I would expect to have to play with it to get it running properly and adjust it as things change . Did CB include a book showing how they wanted the system set up such as fuel pump, filter,  and regulator location and such ?  If not then it is no wonder you have had problems. Factory cars have similar problems as Ron has experianced, I had to upgrade software on customers cars regularly for driveability concerns and this is normal also. I guess it comes down to this, high performance is NOT for everyone and thats ok but if you want it expect to have problems, but what do I know, I am putting a 366 rwhp engine in my street car. Mike McCarthy 

CB includes a detailed install booklet.  I had Henry, at Intermeccanica, install the kit.

I'm going on a five day driving trip next week, but I'm not taking the IM.  I'll be driving through a desert area that can see temperatures in the 90s during the summer months, and I've found that it's when the air temperatures get high that the EFI starts to act up.  I admit that I know very little about fuel injection and even less about trouble-shooting problems. 

I'll take my Miata, because I don't want to be 1000 miles from home and have my engine crap out.

Thanks for the input, Mike.

Mike,

It's really great to have you on this site. Your knowledge and "gentleman's way" of communicating are a rare combination and is quite refreshing.

Welcome to the site!

I am new to this site but not to Speedsterowners.com, I was a member of the old site . Thank you all for your positive comments and I hope to be able to pass on some positive ones of my own, Mike McCarthy

I agree,FI car do not suffer from vapor lock due to thefuel being in a loop. His EFI system ismore than likely not a close loop system with closed loop 02 sensor control. That is why I stick with my statements of temperature compensation being the issue.

 The higher temperature a sensor sees,the leaner the afr will become.

 Here is some of what  used to do,I tuned this VW GTI from 403whp to 463 whp,that is over 500bhp at the engine,and this is with stand alone efi tuning...enjoy!

http://www.youtube.com/watch?v=84H2Z9VpyHM&feature=channel&list=UL 

You can boil fuel at the pump inlet if the gas gets over 120* F. On a hot day and you've been feeding the gas through hot fuel lines for a while, it's possible. Unlikely, but possible. Autoignition temperature of gas is 536* F so running screaming seems a bit excessive . Easy test is just to feel the gas tank when it happens. If it feels uncomfortably hot, chances of it being vapor lock are higher.

Again, in my opinion vapor lock seems unlikely. If a new tune is all it took then I'm glad it was an easy fix.

Justin, I don't know if it's fixed yet.  A true test will be to take the car for a drive on a hot day.  Something in the 85 to 90 degree range.

The engine has always behaved itself in cooler weather, except for the hot start problem, which has plagued this engine since day one.

Was that the old site, or the old, old site, where George Brown would often put his foot in his mouth.  I never met the guy, but miss him, and his vast knowledge on air cooled engines.

The last one, was a bunch of great guys on there too. Mike McCarthy