| Author |
Message |
mjb1980
Samba Member
Joined: April 22, 2014
Posts: 42
Location: Oxford
|
 Posted: Tue Apr 22, 2014 4:06 pm Post subject: Misfire help |
 |
|
Hi all,
Just bought 73 bay with a few engine problems. Its a 1600 and ha Dual Weber Carbs t installed at some point and, Im pretty sure its 009 distributor. I Can get it to start and idle but as soon as you apply throttle I can hear it misfire. Driving it is almost impossible. Have had towed to friend mechanic, but we are not sure where to look first to find cause of misfire. Possibly the carbs have ever been tuned correctly, but with the misfire its hard to tell. We tried adjusting the dizzy cap which helped a little but didn't solve the misfire. Having left for 2 weeks will now no longer start.
Apart from checking obvious (plugs, leads, dizzycap) what steps should I take?
Im tempted to buy a new distributor just to take it out of the equation. I really want to get it onto a rolling road so that the carbs can be configured properly, but getting it to running first would be good.
I will be honest and say my knowledge is very limited and learning only from what I read on here so any help would be appreciated.
Thanks |
|
| Back to top |
|
 |
OLD VW NUT
Samba Member
Joined: February 23, 2011
Posts: 2776
Location: High Desert of Washington 98823
|
| Posted: Tue Apr 22, 2014 6:54 pm Post subject: |
|
|
Why not start with a step by step full Monty tune up? Adjust valves - replace all ignition parts - if you have a known good coil put that in for the time being until you get the engine running good then stick the old coil back in.
_________________
71 Ghia Coupe - stock body - no rust! Powered by a 2110 W/Dual HPMX 44's - Rancho Pro Street Transaxle - A/C by Gilmore
Other car - 2013 VW Golf TDI |
|
| Back to top |
|
|
mjb1980
Samba Member
Joined: April 22, 2014
Posts: 42
Location: Oxford
|
| Posted: Sun May 11, 2014 12:58 pm Post subject: |
|
|
| OLD VW NUT wrote: |
| Why not start with a step by step full Monty tune up? Adjust valves - replace all ignition parts - if you have a known good coil put that in for the time being until you get the engine running good then stick the old coil back in. |
Hi chaps,
So I got a gun and found the the correct marks to adjust the timing so its correct. But Im still unable to get rid of the misfiring issue I have. Even when the timing is set to be spot on the car is heavily misfiring so its almost impossible to drive. I can start another thread for this,or I will just explain on here what I have done already. Here goes.
What ive got - 1600 engine with twin EMPI ICT 34 carbs.
What I have done:
Installed accuspark ignition kit (plugs, leads, coil, SVDA dist.)
Installed a fuel regulator.
Changed the Main jet (150), idle jet (55) and Emulsion (F6) tube on the carbs.
Idle mixture screw 1 and 1/2 turns out although changing this does nothing.
The engine seems to idle OK but I can here a faint knock sound. As soon as I add in throttle the engine breaks under load and pops heavily. The only thing that's slightly odd is that at TDC the distributor rotar arm of the accuspark SVDA was was pointing at position 2 rather than one so I just swapped over the leads.
Not sure what to do next but i think a new distributor might be a good idea? |
|
| Back to top |
|
|
rustybusjef
Samba Member
Joined: December 19, 2011
Posts: 329
Location: EVERETT WASHINGTON
|
| Posted: Sun May 11, 2014 1:39 pm Post subject: |
|
|
| make sure high tension leads are in correct order, (1,4,3,2,)and adjust the valves. then check to see if carbs are in sync. And I suppose a compression and/or leakdown test should be done to make sure engine can be tuned. |
|
| Back to top |
|
|
mjb1980
Samba Member
Joined: April 22, 2014
Posts: 42
Location: Oxford
|
| Posted: Sun May 11, 2014 1:42 pm Post subject: |
|
|
[quote="rustybusjef"]make sure high tension leads are in correct order, (1,4,3,2,)and adjust the valves. then check to see if carbs are in sync. And I suppose a compression and/or leakdown test should be done to make sure engine can be tuned.[/quote
OK thanks, how would I go about a compression/ leakdown test? |
|
| Back to top |
|
|
rustybusjef
Samba Member
Joined: December 19, 2011
Posts: 329
Location: EVERETT WASHINGTON
|
| Posted: Sun May 11, 2014 4:31 pm Post subject: |
|
|
First you must purchase one of the tools . Either a compression tester or a leakdown tester or both . A compression tester will tell you how much pressure the engine can build up . With the spark plugs out and carbs at full throttle screw gauge into head one cylinder at a time , crank engine till gauge stops climbing -record this reading . Do all four and compare , they should be about 150 to 120 psi or whatever the British equivalent is .
A leakdown test is done at TDC and measures leakage in percent .But it can help you learn where your leakage is by listening ; hissing at carb - intake valve , hissing at breather - bad rings . http://www.amazon.co.uk/Silverline-598559-Compression-Testing-5-Piece/dp/B0015NRKFE
http://www.ebay.co.uk/itm/450845-Car-Engine-Cylind...1484794289 |
|
| Back to top |
|
|
ciclibera
Samba Member
Joined: May 29, 2014
Posts: 1
Location: California
|
| Posted: Fri Jun 06, 2014 6:28 pm Post subject: |
|
|
| Hey mjb, howd the misfire turn out? It sounds like youre having had similar issues as Ive had over the years. My setup sounds similar too. Is yours a type III?... Thats not stated already is it? |
|
| Back to top |
|
|
|
