Alfa Romeo Bulletin Board & Forums - Reply to Topic
Thread: engine compression? Reply to Thread
Title:
Message:
Post Icons
You may choose an icon for your message from the following list:
 

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










  Additional Options
Miscellaneous Options

  Topic Review (Newest First)
07-30-2019 10:16 AM
slowcreek
Quote:
Originally Posted by 930cabman View Post
The theory of introducing some flammable gas into the intake manifold works. We recently did exactly that and appeared to find the culprit with the soft mounts. New soft mounts and $120.00 later the loping idle and lack of a decent reading with our vacuum gauge leads me to believe the starting fluid test did not perform as intended. Not sure where to go from here, has anyone had luck with the "smoke test" for vacuum leaks in the intake system?

Yes, we are off topic
The problem with starting fluid is that it mostly evaporates before reaching the suspected vacuum leak source. I use brake cleaner or carb cleaner. You can use water if you like. You'll know when it hits the leak......
07-29-2019 11:47 AM
930cabman The theory of introducing some flammable gas into the intake manifold works. We recently did exactly that and appeared to find the culprit with the soft mounts. New soft mounts and $120.00 later the loping idle and lack of a decent reading with our vacuum gauge leads me to believe the starting fluid test did not perform as intended. Not sure where to go from here, has anyone had luck with the "smoke test" for vacuum leaks in the intake system?

Yes, we are off topic
02-25-2015 11:48 AM
JimPunkrockford
Quote:
Originally Posted by gprocket View Post
You can check for air leaks by spraying starter fluid around the mounts. Some use propane gas. If the motor speeds up you likely have a leak.
okay, this may be something. here is a video of the test. it is hard to tell because of such funky idling but maybe....

02-23-2015 10:23 PM
JimPunkrockford
Quote:
Originally Posted by gprocket View Post
You can check for air leaks by spraying starter fluid around the mounts. Some use propane gas. If the motor speeds up you likely have a leak.
ahh that's what i was looking for. thanks i will give that a try.
02-23-2015 10:08 PM
gprocket You can check for air leaks by spraying starter fluid around the mounts. Some use propane gas. If the motor speeds up you likely have a leak.
02-23-2015 09:56 PM
JimPunkrockford
Quote:
Originally Posted by GTVMk1 View Post
Have you checked for air leaks in the rubber carbie mounts?
This will definitely make the car run like a dog when everything else appears ok.

Wazza.
i did a visual check before reinstalling the carbs. they seemed good, but i did not take them off the car to inspect. is there a way to test them? how do they come off?
02-23-2015 03:34 PM
GTVMk1 Have you checked for air leaks in the rubber carbie mounts?
This will definitely make the car run like a dog when everything else appears ok.

Wazza.
02-23-2015 02:43 PM
JimPunkrockford okay, checked the cam timing marks. i am assuming these are them and they are on at TDC.

i ordered a carb sync tool, so the carbs may still be out of tune here but here are some videos of the car running, the idle gets really fast after the car has warmed up, but like i said, we will see after i re-sync the carbs



02-21-2015 12:15 PM
101/105guy I am joking about the cams, althou some here think all Alfa cams are worn.
This method of trouble-shooting is the least likely to get results as there are so many opinions to check.
On owner went on for a long while checking and replacing parts until he found that the exhaust pipe had been filled with acorns by an industrious squirel.
Do a proper trouble shooting method. System by system as a pro would do.
02-21-2015 12:38 AM
JimPunkrockford
Quote:
Originally Posted by NMMilano View Post
Rebuilt carbs? I'm going guess the carbs are out of sync
New distributor, are you sure the timming is right?
It sounds like you have what you need, putting in new rings would be throwing money away.
Here is a good article on setting the carbs, Daves home page
carbs may indeed be out of sync. i need a sync tool and that link will be of great use, thanks

i believe the timing is right

Quote:
Originally Posted by alfaparticle View Post
Which carbs are you using - the full model number?
full number? i don't remember dcoe 40s xxxx....

Quote:
Originally Posted by 101/105guy View Post
Maybe your cams are flat......

interesting thought, i'll post some pics


Quote:
Originally Posted by gprocket View Post
It would probably be useful to define what the motor is doing:
Hard starting?
Rough idle? Rough running at certain speeds? At All speeds?
Lacking power at certain points?
Backfire out exhaust?
Backfire out of intake?
Is it worse cold, hot or all the time?
Blue smoke?, white smoke? Black smoke? No smoke?
Water in oil? Oil in radiator? Oil leaks around the head?

I'm sure there are plenty of other maladies, these are just off the top of my head.

If you can make a youtube video and post it, it may help in the diagnosis.

Sounds like you just need some tweaking and not a lot of money. I know this is not a SPICA motor but I find it interesting when you are dialing in the FI pump that as you go the motor runs crappier and crappier until the final twist of the screw driver and then every thing falls in place and it runs fine. Unnerving in the process though...
yes i should of said all this first, sorry

hard to start cold, rough idle, uneven idle, will go up then die down.

lacking power when you accelerate, also a large bog if you floor the gas pedal.

backfire out of intake, and i retarded the timing from the mark and it runs a little better.

no smoke, no leaks. here is a video of it running


thanks for the help everyone, and the shoulder to cry on
02-20-2015 04:09 PM
gprocket It would probably be useful to define what the motor is doing:
Hard starting?
Rough idle? Rough running at certain speeds? At All speeds?
Lacking power at certain points?
Backfire out exhaust?
Backfire out of intake?
Is it worse cold, hot or all the time?
Blue smoke?, white smoke? Black smoke? No smoke?
Water in oil? Oil in radiator? Oil leaks around the head?

I'm sure there are plenty of other maladies, these are just off the top of my head.

If you can make a youtube video and post it, it may help in the diagnosis.

Sounds like you just need some tweaking and not a lot of money. I know this is not a SPICA motor but I find it interesting when you are dialing in the FI pump that as you go the motor runs crappier and crappier until the final twist of the screw driver and then every thing falls in place and it runs fine. Unnerving in the process though...
02-20-2015 02:17 PM
101/105guy Maybe your cams are flat......
02-20-2015 02:09 PM
alfaparticle Which carbs are you using - the full model number?
02-20-2015 01:43 PM
NMMilano Rebuilt carbs? I'm going guess the carbs are out of sync
New distributor, are you sure the timming is right?
It sounds like you have what you need, putting in new rings would be throwing money away.
Here is a good article on setting the carbs, Daves home page
02-20-2015 01:24 PM
JimPunkrockford
dang

i am bummed about this. i bought a new compression test kit. and the compression seems okay now.

i really just wanted to know why the car runs so bad, bad rings would of at least given me something instead of just throwing money at this stupid car.

first pic is cold the second is hot.

so....
rebuilt the carbs,

new distributor and coil

good compression

should i still check the cam timing?

this thing is too much
This thread has more than 15 replies. Click here to review the whole thread.

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome