Starting problem after new cam.

Bobbybedtime · Post by **Bobbybedtime** » Mon Mar 08, 2010 9:37 pm

Well,
Decided to check the injectors ... wasn't expecting much of a problem as they had been serviced then kept in the air tight bags whilst I put it all together.
Glad I did, found three injectors suck plus the cold start injector. Freed the main injectors up, couldn't do much with the cold start injector, played with the timimg and its running pretty well. Managed to get twenty minutes at approx 2500 rpm today to run the camshaft in so well pleased, thank you Mr Super V8.
I do still appear to have the original problem ... crankshaft and valley overpressuring and pushing oil out. Will investigate further in case its just me being oversensitive with one or two oil leaks.
Thanks again,
BBT.

SuperV8 · Post by **SuperV8** » Tue Mar 09, 2010 12:31 pm

I never actually used the cold start injector on mine and it always started ok. It is a summer car but I do drive it when its cold, although maybe not freezing.

Regarding the over pressurising and blowing oil out. Is your flame trap clear? Mine was full of crap.

Tom.

ramon alban · Post by **ramon alban** » Mon Mar 15, 2010 8:51 am

Bobbybedtime wrote:Checked the info from the net against the vitesse manual and if the pin positions on the ecu are correct (net info) this suggested the injectors fire in groups 1,2,3,4, & 5,6,7,8, if this is right then changing the plugs will make a difference.

Will swap them back to double check as I cant find any info on the net other than the injectors fire 1,3,5,7, & 2,4,6,8, which doesnt add up.

Bit confused at the moment.

Hello Bobby, to help you out of the state of confusion, I suggest you read the pdf available from this link:

http://www.vintagemodelairplane.com/pag ... tor01.html

Everything you could possibly want to know about your injectors.

Then go into my efi archive to uncover similarly comprehensive info on all the other efi components. - Yes, Everything! The whole 9 yards will explain the purpose, function and testing for pretty much the whole flapper system as fitted to your car.

Then dig around, there is loads more efi stuff on my other pages that may take your interest.

Bobbybedtime · Post by **Bobbybedtime** » Mon Mar 15, 2010 7:19 pm

Hi Ramon,
Thanks for the reply, the link you have attached is the one I used for info, very helpful and detailed which makes it harder to challenge. If I can copy the vitesse manual drawing I will post as it shows a difference. Must say I havent swapped them back yet. Willl probably do tomorrow.

Did find a problem tonight with crankcase pressure. The metal tube that goes into the plunum was positioned such that the hole in the tube did not line up with the hole in the plenum ... it was pointing straight down. When I removed the rocker end to blow through I lifted the hose and the pipe swiveled up exposing the hole so when I blew through it didn't seem blocked. Havent run it yet but effectively this was sealed all the time it was connected. Here's hoping this is the problem with crankcase pressure.

Also, is ther a preffered way to do a compression test. I did mine cold and was getting between 120-140 psi, warmed engine and got 150psi. Do you run it without firing and throttle open?
Regards,
BBT.

ramon alban · Post by **ramon alban** » Mon Mar 15, 2010 10:23 pm

Bobbybedtime wrote:Hi Ramon, Thanks for the reply, the link you have attached is the one I used for info, very helpful and detailed which makes it harder to challenge.

Bobby, If you think you have found an error or omission on my web pages, I need to know so I can check/correct as required.

Some material can be error free, most is not, as I found with my source documents, which were littered with whatI considered to be mistakes. having said that, diagrams can also contain typos as well as text.

Even tho its a hobby site, because lots of peeps rely on my web pages I need to try my best to keep them accurate.

Now, opinions vary and are a different thing altogether, but at least the facts should be correct.

Many thanks

Ramon

ramon alban · Post by **ramon alban** » Mon Mar 15, 2010 11:39 pm

Bobbybedtime wrote:When I removed the rocker end to blow through I lifted the hose and the pipe swiveled up exposing the hole so when I blew through it didn't seem blocked. Havent run it yet but effectively this was sealed all the time it was connected. Here's hoping this is the problem with crankcase pressure.

Also, is there a prefered way to do a compression test. I did mine cold and was getting between 120-140 psi, warmed engine and got 150psi. Do you run it without firing and throttle open?

Bobby, I came across the breather fault you describe only once before, not personally, but anecdotally on a forum and it drove the owner and his fellow forum members to distraction. You can see why, the bloke was totally convinced yet all the symptoms screamed - blockage.

I distilled a method of compression testing which seems to satisfy most needs.

Compression testing

# Warm engine to running temp, switch off.

# Remove all spark plugs

# Remove king lead or disconnect power to coil.

# Compression gauge into each cylinder in turn, throttle wide open, crank engine.

# Watch how the gauge increases its reading getting close to maximum within 2 to 3 revolutions. Note any laggards.

# Keep cranking until the reading stabilizes.

# Target readings may vary according to high or low compression engine and factors like throttle position, oil in cylinders, temperature, cylinder config, etc.

# Generally anything above 130 psi is OK but obviously, the higher the better.

# Even if OK the main thing to look for is the difference between the cylinders.

# Differences of more than (say) 10 psi may indicate a number of sad cylinders.

# The larger the difference, the worse the problem, but always recheck to eliminete test malfunction.

# Low adjacent cylinders would indicate possible breached head gasket.

# Not having throttle wide open for any of the readings would have only marginal effect when looking for differences.

# To measure actual PSI, not having the throttle open restricts air intake to give slightly lower readings.

# Introducing oil in the cylinder will likely increase readings especially where valve seating may be imperfect.

# Oil in a V8 may not give an expected increased reading because a piston being at an angle initially inhibits oil going all around the rings.

# Log all the results for later study/comparison

Errors and Omissions Please, Work in Progress

Bobbybedtime · Post by **Bobbybedtime** » Mon Mar 22, 2010 8:47 pm

Hi Ramon,
Really good useful write ups, I used them to test my system.
My scanner has broke so I've taken some photo's of the haynes manual, not great but you can read if you zoom in.
Please cross ref the photos with the attached links.

The fiirst one, injector circuit, paragraph 3, specifically ecu pins.

http://www.vintagemodelairplane.com/pag ... tors01.pdf

http://www.vintagemodelairplane.com/pag ... cuit01.pdf

Its probably easier if you have a look rather than me try to write. You will see in the pre 84 diagram the injectors are numbered by haynes.
I'll post the photos next as I'm having trouble attaching and I've already had to write this twice.
Regards,
BBT.

Bobbybedtime · Post by **Bobbybedtime** » Mon Mar 22, 2010 8:55 pm

hI rAMON,
Not doing to well attaching photo's, can I email them to you.

The twisted pipe in the plenum was the problem, with it in the correct place no pressure in the crank case at all.

Not done the compression test yet but will shortly.
Regards,
BBT.

ramon alban · Post by **ramon alban** » Mon Mar 22, 2010 9:52 pm

Bobby, yes please. put a dot in the dotty

ramondottyalban@btinternetdottycom

Ramon

Bobbybedtime · Post by **Bobbybedtime** » Thu Mar 25, 2010 6:19 pm

Hi Ramon,
Hopefully you recieved the email.
Regards,
BBT.