 Fixed! Thank you all!, Carbs! |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| CG-914 |
 Mar 5 2013, 08:10 AM
Post
#1
|
|
Member  Group: Members Posts: 323 Joined: 27-December 10 From: LA/OC CA Member No.: 12,526 Region Association: Southern California  |
I put the engine back in my car on Saturday that I and a very great friend build. The engine set up:
74 2.0 Euro Mahle Pistons 8:1 set at 8.2:1 9550 RAT Cam with the whole Valve Train set up Mallory Distributor Set up by Chris I put 40 IDF Weber Carburators brand new With 28 Ventures Idle jets are 55 Molsifire 20C 115/F11 The Car ran strong smooth Then I had a charging Problem and the Car started to ran worse and worse a lot of misfire. I fixed the Charging issue but I still runs worse and worse especially when you drive it longer then 15 min. I am think its the carbs but I blew out the jets after taking them out of the carbs. Still not better... Any ideas? Btw I am not looking for a discussion about a 9550 cam with carbs! |
   |
 
|
| bandjoey |
Mar 5 2013, 08:23 AM
Post
#2
|
|
bandjoey Group: Members Posts: 4,926 Joined: 26-September 07 From: Bedford Tx Member No.: 8,156 Region Association: Southwest Region |
Fuel pump issues? If it ran strong and now does not it sounds fuel related. If not the carbs what's left? Pump, fuel, fuels lines Filter? Isolate and test each part. Report back. I'm sure someone else will help.
How bout run the carbs from a gas can. If it smooths out you know it's in the lines. If it still runs bad its in the carbs... Also. Describe misfire better. Popping in the carbs? Backfire. Just a continuous sputtering motor? Good luck. |
|
|
|
| CG-914 |
Mar 5 2013, 08:36 AM
Post
#3
|
|
Member Group: Members Posts: 323 Joined: 27-December 10 From: LA/OC CA Member No.: 12,526 Region Association: Southern California |
Some Back fire mostly popping in the carbs (especially on the passenger side) lean?
Feels like its not running on all 4! Also now it does not even start well |
|
|
|
| mrbubblehead |
Mar 5 2013, 08:56 AM
Post
#4
|
|
Twodollardoug Group: Members Posts: 1,155 Joined: 17-December 10 From: calimesa ca. Member No.: 12,492 Region Association: Southern California |
maybe your charging problem did something to the unilite? do you have a nother dizzy you can drop in to verify?
|
|
|
|
| rhodyguy |
Mar 5 2013, 11:10 AM
Post
#5
|
|
Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,080 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
did you clean your tank for your brand spankin' new engine? mesh filter in the tank or a new fuel filter? avoid the little vw style. if the idle jets are plugged it's going to run poorly ALL of the time until you're off of the idle/progression circuits. the simplest test for plugged idle jets is the engine response when you gently close the idle air mixture screws (one at a time) on what you presume is the offending carb. what version of plug wires are you running? it's all pretty well spelled out in the Weber book from CBperformance. esp in the trouble shooting guide. stick a flow meter on the front barrels of each carb on a warm engine at idle. if the readings are different your linkage is off or you could have a vacuum leak in the induction system. so many variables with carbs...hard to diagnose with limited data.
what is a Molisfire 20C? the 115s are your main jets yes? |
|
|
|
| ThePaintedMan |
Mar 5 2013, 11:23 AM
Post
#6
|
|
Advanced Member Group: Members Posts: 3,886 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States 
|
QUOTE(rhodyguy @ Mar 5 2013, 12:10 PM)  did you clean your tank for your brand spankin' new engine? mesh filter in the tank or a new fuel filter? avoid the little vw style. if the idle jets are plugged it's going to run poorly ALL of the time until you're off of the idle/progression circuits. the simplest test for plugged idle jets is the engine response when you gently close the idle air mixture screws (one at a time) on what you presume is the offending carb. what version of plug wires are you running? it's all pretty well spelled out in the Weber book from CBperformance. esp in the trouble shooting guide. stick a flow meter on the front barrels of each carb on a warm engine at idle. if the readings are different your linkage is off or you could have a vacuum leak in the induction system. so many variables with carbs...hard to diagnose with limited data. what is a Molisfire 20C? the 115s are your main jets yes? I think he meant emulsion tubes. Those should be F11s for pretty much ANY Type 4 engine, right Kevin? I don't know what 20Cs are. 115s are small - that's what I had which was causing my hesitation/stumble from the idle circuit to main. But like you said, there are a number of variables to cover first before even approaching the jets. I think it sounds a lot like fuel filter/pump related. But I'll echo everyone else's sentiments... we need more info about the setup and the problem. |
|
|
|
| yeahmag |
Mar 5 2013, 11:36 AM
Post
#7
|
|
Advanced Member Group: Members Posts: 2,421 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California
|
Do you have a points replacement system of any sort?
|
|
|
|
| ChrisFoley |
Mar 5 2013, 12:21 PM
Post
#8
|
|
I am Tangerine Racing Group: Members Posts: 7,925 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None
|
My suggestion is to change to 32mm vents, 50 idles, 125 mains and see what happens.
|
|
|
|
| ChrisFoley |
Mar 5 2013, 12:22 PM
Post
#9
|
|
I am Tangerine Racing Group: Members Posts: 7,925 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None
|
QUOTE(yeahmag @ Mar 5 2013, 12:36 PM) Do you have a points replacement system of any sort? Mallory Unilite |
|
|
|
| yeahmag |
Mar 5 2013, 12:24 PM
Post
#10
|
|
Advanced Member Group: Members Posts: 2,421 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California
|
Reason I ask is if the idle jets aren't plugged I had a Unilite module fail in just that way. You can see it with a timing light as an unsteady timing at a fixed rpm. Worth looking at and easy to fix. I started running the Mallory widget that protects the module myself.
-Aaron |
|
|
|
| FourBlades |
Mar 5 2013, 05:53 PM
Post
#11
|
|
From Wreck to Rockin Group: Members Posts: 2,054 Joined: 3-December 07 From: Brevard, FL Member No.: 8,414 Region Association: South East States
|
I think the Mallory just quits altogether if the optical module fails. I say fouled plugs? or maybe clogs somewhere in your carbs. There are numerous places IDFs can clog on you, like anywhere from the main stacks to the AF control screws and not just the idle jets themselves. John |
|
|
|
| yeahmag |
Mar 5 2013, 05:56 PM
Post
#12
|
|
Advanced Member Group: Members Posts: 2,421 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California
|
That is one fail mode, but I have experienced the mode I described first hand - in my car.
QUOTE(FourBlades @ Mar 5 2013, 03:53 PM) I think the Mallory just quits altogether if the optical module fails. I say fouled plugs? or maybe clogs somewhere in your carbs. There are numerous places IDFs can clog on you, like anywhere from the main stacks to the AF control screws and not just the idle jets themselves. John |
|
|
|
| FourBlades |
Mar 5 2013, 06:44 PM
Post
#13
|
|
From Wreck to Rockin Group: Members Posts: 2,054 Joined: 3-December 07 From: Brevard, FL Member No.: 8,414 Region Association: South East States
|
I did not know they could partially fail. I went out to start my car one day and it would crank fine but no fire. On a whim I switched out the optical module and it was back in business. Went right inside and ordered the circuit guard module and never had a problem again. I still bet the OP's carbs are clogged somewhere because that is such a common problem with IDFs. John |
|
|
|
| Gint |
Mar 5 2013, 06:46 PM
Post
#14
|
|
Mike Ginter Group: Admin Posts: 16,071 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains  |
You know, my car is starting sort of similar kind of symptoms. Runs great until it gets good and hot and then starts some stumbling crap. Mild, but it's just not quite as strong or smooth at that point. The last time I had it out and hot, the tach started bouncing (beyond normal 914 tach bounce) 1k rpm swing from 4k to 3k, like a drop. I've been wondering if my Mallory is all right...
|
|
|
|
| Jake Raby |
Mar 5 2013, 07:38 PM
Post
#15
|
|
Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE I put 40 IDF Weber Carburators brand new Sounds like the problem... Carbs simply can't be ran out of the box these days. |
|
|
|
| McMark |
Mar 5 2013, 08:07 PM
Post
#16
|
|
914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
QUOTE(FourBlades @ Mar 5 2013, 03:53 PM) I say fouled plugs? That's my thought too. QUOTE(Gint @ Mar 5 2013, 04:46 PM) You know, my car is starting sort of similar kind of symptoms. Runs great until it gets good and hot and then starts some stumbling crap. Mild, but it's just not quite as strong or smooth at that point. The last time I had it out and hot, the tach started bouncing (beyond normal 914 tach bounce) 1k rpm swing from 4k to 3k, like a drop. I've been wondering if my Mallory is all right... The only time I've ever experienced that was when the coil clamp was loose and the coil negative was grounding to the engine tin. But this could also happen if the Mallory stops triggering intermittently. |
|
|
|
| ChrisFoley |
Mar 5 2013, 09:44 PM
Post
#17
|
|
I am Tangerine Racing Group: Members Posts: 7,925 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None
|
If you have a Mallory coil, try swapping it out for a stock or Bosch Blue coil. We've noticed problems with some coils when they get hot.
|
|
|
|
| ThePaintedMan |
Mar 5 2013, 11:41 PM
Post
#18
|
|
Advanced Member Group: Members Posts: 3,886 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States
|
Apparently this thread doesn't need to be named Urgent since the OP hasn't responded. (IMG:style_emoticons/default/dry.gif)
|
|
|
|
| Gint |
Mar 6 2013, 07:12 AM
Post
#19
|
|
Mike Ginter Group: Admin Posts: 16,071 Joined: 26-December 02 From: Denver CO. Member No.: 20 Region Association: Rocky Mountains |
He's busy working on the car!
|
|
|
|
| CG-914 |
Mar 6 2013, 09:21 AM
Post
#20
|
|
Member Group: Members Posts: 323 Joined: 27-December 10 From: LA/OC CA Member No.: 12,526 Region Association: Southern California |
QUOTE(Gint @ Mar 6 2013, 08:12 AM) He's busy working on the car! I was working on the car all day! And it was urgent because I plant to move to California this morning with the car but now I will leave tomorrow morning.... I tried everything you guys recommended and thank you all for your help (IMG:style_emoticons/default/pray.gif) !!!! It turned out to be the new Webers... The holding Nut for the needle pump came loose, so the Float where stocked at empty but the pump was cramped close so the right side was starving for fuel (IMG:style_emoticons/default/headbang.gif) (IMG:style_emoticons/default/dry.gif) ! Now the engine is running AWSOME! (IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/driving.gif) I love the 9550! Best cam I drove ever Jake! |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 15th May 2024 - 10:51 AM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.