| FAQ |
| Members List |
| Social Groups |
| Calendar |
| Search |
| Today's Posts |
|
#1
08-04-2003, 07:22 PM
|
||||
|
||||
new 406ci in my 67 Firebird
new 750cfm edelbrock carb new holley pump gas and regulator new spark plugs, wires, rotor and distributor cap car ran well for 3 months but just start to bug over 4000 rpm. I can use the car without any problem as long as I dont accelerate strong over 4000 rpm. I don't know if it's missing gas or sparks. Does anybody have an idea where I should look first?? http://firstgenfirebird.org/show/closeup.mv?CarID=341 Montebello, Quebec, Canada |
|
#2
08-04-2003, 07:22 PM
|
||||
|
||||
|
new 406ci in my 67 Firebird
new 750cfm edelbrock carb new holley pump gas and regulator new spark plugs, wires, rotor and distributor cap car ran well for 3 months but just start to bug over 4000 rpm. I can use the car without any problem as long as I dont accelerate strong over 4000 rpm. I don't know if it's missing gas or sparks. Does anybody have an idea where I should look first?? http://firstgenfirebird.org/show/closeup.mv?CarID=341 Montebello, Quebec, Canada |
|
#3
08-04-2003, 08:03 PM
|
|||
|
|||
|
By Bugging, I'm guessing you mean that it has a stumble or a miss above 4000 rpm!? If so, it is more than likely either spark or gas. Can you reproduce the problem with the car not moving? Or does it only happen while you are driving?
Things to check: Fuel filter Fuel pressure (at 4000rpm) bent or misadjusted secondary linkage on carb distibutor cap on properly worn/damaged contacts in the distributor cap broken or melted spark plug wire coil connectons, or bad coil You don't say what distributor you are using, HEI? Mallory? Any add on controllers? When it "bugs" do you smell gas, or get backfires through the carb? A little more info can help find the problem quicker!  If it has ti*s or tires, it's gonna cost ya!
__________________
If it has ti*s or tires, it's gonna cost ya! |
|
#4
08-05-2003, 03:55 AM
|
||||
|
||||
|
yes it bugging on each gears and neutral and it doesn't smell gas.
I have factory HEI, module and coil. http://firstgenfirebird.org/show/closeup.mv?CarID=341 Montebello, Quebec, Canada |
|
#5
08-05-2003, 05:38 AM
|
|||
|
|||
|
Could possibly be the control module in the HEI, but those usually cause the car not to start at all. I'm thinking it is more of a carb problem, check your pressure after the regulator, with the engine running at idle, then increase rpm's and monitor the pressure. Your fuel filter could be partially clogged, or your regulator could be bad or need adjusting. Hope this helps.
If it has ti*s or tires, it's gonna cost ya!
__________________
If it has ti*s or tires, it's gonna cost ya! |
|
#6
08-05-2003, 07:08 AM
|
||||
|
||||
|
Weird.
 Mine is doing the same thing but @3000 rpm. It only does it in gear I beleive though. No back fires through carb or smell of gas. I have a few things that I want to do including replacing the fuel filter. My vac. advance is not functioning either so that may be hurting me too. Plugs definitely should replaced. Guess that I will keep an eye on this post.  <A HREF="http://www.geocities.com/rpk76/1979.htm" TARGET=_blank>79TA455 </A> |
|
#7
08-05-2003, 02:49 PM
|
||||
|
||||
|
What type of Carb are you running? I had a factory quadrajet drop a secondary jet needle. It fell down into the jet & the car would not rev over 4K. It did not miss bad though. It just would fall on its face. Once I pulled it apart, I also found the float level was too low in the bowl. I don't think that was helping anything either.
68ragtop 1968 GTO Convertible (currently my resto project) 1978 Gold Edition Trans am 1979 10th aniversary T/A 1980 Pace Car Trans am
__________________
 68 GTO 4-spd Convertible 78 S/E Trans am L78, WS6 Auto 78 S/E Trans am W72, WS6 Auto 79 10th aniv W72 Trans am 80 Indy pace car Trans am 89 Trans am GTA |
|
#8
08-05-2003, 02:55 PM
|
||||
|
||||
|
Coil could be taking a dump.
__________________
You know it's going to be a good day when you wake up breathing! |
|
#9
08-06-2003, 02:21 AM
|
||||
|
||||
|
Mine did exactly the same thing at exactly the same rpm. Bad coil - replaced it and the problem instantly went away.
Agree with Larry that bad module would probably cause the car to not start. Poor fuel supply would likely cause it to fall on it's face rather than stumble. If the stumble goes away when you let up on it I'd put my money on the coil. http://kurtspontiac.homestead.com/TimSimpson66GTO.html |
|
#10
08-06-2003, 10:07 AM
|
||||
|
||||
|
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by 68ragtop:
What type of Carb are you running? 68ragtop<HR></BLOCKQUOTE> I have a 750 Holley single pump, double feed. <A HREF="http://www.geocities.com/rpk76/1979.htm" TARGET=_blank>79TA455 </A> |
|
#11
08-06-2003, 10:38 AM
|
||||
|
||||
|
A couple other things to check:
What is the voltage (while running) at the coil (+)? It should be full battery voltage (13-14v). If the factory resistance wire from the ignition switch to the coil wasn't replaced or bypassed when the HEI was installed, it will cause a weak spark, missing, and low power at higher RPM's. Also, if you're running the stock coil, they are notorious for getting weak with age. |
|
#12
08-07-2003, 04:21 AM
|
||||
|
||||
|
I'm not sure yet but I found the gas line bend direct at the carb connector under the air filter. But I cannot try it yet and hit the throttle to make it happend because it's raining like hell every night since then.
So before to go farther I'll wait to test that. http://firstgenfirebird.org/show/closeup.mv?CarID=341 Montebello, Quebec, Canada |
|
#13
08-10-2003, 02:15 AM
|
||||
|
||||
|
Going to the track tomorrow, I should say today and I can't wait.
Have you ever seen a factory HEI coil missing fire only over 5500 rpm? I resolved the gas problem but now once and a while it is doing back fire in the exhaust when I hold it over 5500. New cap, rotor, wires. http://firstgenfirebird.org/show/closeup.mv?CarID=341 Montebello, Quebec, Canada |
|
#14
08-11-2003, 03:56 AM
|
||||
|
||||
|
went to the track but it was raining.
http://firstgenfirebird.org/show/closeup.mv?CarID=341 Montebello, Quebec, Canada |
| Reply |
|
|
The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.
Linear Mode
