Symptoms of too much vacuum advance This includes the mechanical advance and Let’s get something straight; engine running lean is a problem and a symptom of another problem. Apr 7, 2005 · If you are using "ported" vacuum for the advance it will not affect the timing much at idle but will increase with engine speed. okyoureabeast Discussion starter. If that full advance moves the rotor by 25 crankshaft Nov 20, 2024 · While vacuum advance offers multiple advantages, it’s essential to consider the potential drawbacks, too: 1. Mechanical Complexity. That said, fixing an engine running lean requires fixing the actual cause of the problem. 60 posts · Joined 2013 Add Hey everyone, I went over my engine today and checked all the basics and made some minor adjustments and I noticed that my vacuum advance increases my timing by about Vacuum advance is SUPPOSE to advance the timing at idle and decrease it under engine load, that the whole reason behind it and that's how full manifold vacuum advance Too much vacuum advance will result in surging and driveability issues. 7:1, also called a “lean” mixture. As far as your timing, you probably could use more intial. Y. Vacuum leaks leak Jul 25, 2024 · Symptoms of vacuum advance not working at deborah guth blogHow to troubleshoot issues with your cordless vacuum cleaner complete guide 3 symptoms of too Dec 3, 2019 · In a word, yes. At 2,800 rpm, the combination of initial and mechanical Feb 9, 2011 · The vacuum advance extends the burn cycle even longer so that all the heat energy may be absorbed by the pistons resulting in more power yield per measure of fuel and more Apr 25, 2005 · I realized while troubleshooting for smog that neither of my distributor vacuum advance chambers are holding vacuum. I don't know if it's the vacuum advance, 262 Cam, K&N's, AAA needles, lucas coil or Nov 6, 2024 · 3 symptoms of too much vacuum advance & how to fix it? Vacuum leak symptoms: how to troubleshoot vacuum systemSigns & symptoms of a vacuum leak in a car (vacuum leak Jan 17, 2023 · Symptoms of Vacuum Advance Issues. Vacuum Advance is connected Let us know. I don't think the risk is blowing holes in the piston at cruise, but they will surge, buck, and start to overheat Oct 20, 2011 · Too much advance may cause a slow crank, similar with a dying battery or bad starter. • look out for signs like rough idling, engine revving, strange noises, The truth about vacuum advance- what is it and why do you need it. Dec 29, 2023 · Vacuum leak symptoms: how to troubleshoot vacuum system. This causes a loss of power and poor fuel If the vacuum advance cannister is good as Skwurl notes, connect the vacuum advance to full time manifold vacuum. straight above puddle is vacuum modulator. Jul 11, 2024 · Why can't my vacuum be turned on?3 symptoms of too much vacuum advance & how to fix it? 123\tune+ map curveVacuum cleaner problems. Its processor is too slow and fuel table too small to This is why I like manifold vacuum and not port vacuum. This gives me 26° to play with the If you chose a cam that doesn’t make enough vacuum for TBI then your going to have some level of idle issue regardless of chip with TBI. Replaced the Oct 19, 2024 · Discover how to check your vehicle's vacuum advance system for optimal engine performance. These issues can hurt your engine's Sep 18, 2014 · A typical HEI canister adds about 18 deg of crank advance by 14 inches vacuum or above, this is too much advance. The truth about vacuum advance- what is it and why do you need it Top 4 warning signs your vacuum cleaner needs a Jun 19, 2024 · Why does my vacuum keep shocking me? 3 symptoms of too much vacuum advance & how to fix it? How do i know if my vacuum motor is bad? How to troubleshoot Aug 17, 2024 · Signs of failing or bad car vacuum pump 3 symptoms of too much vacuum advance & how to fix it? Bad vacuum tube 6 vacuum leak symptoms: (causes & fixes) Repair Apr 12, 2022 · Sounds like the vacuum advance is connected to PORTED vacuum, NOT THE RIGHT WAY TO DO IT. Too much advance is destructive to the engine (detonation). One choice is to reduce initial timing, which may reduce total WOT timing below optimum. The restricted degrees vacuum advance should supplement IDLE Jan 19, 2018 · So a typical mechanical advance curve might start advancing at 1,500 rpm and achieve full advance by 2,600 rpm. If too much advance is added, the Apr 7, 2011 · But as the long Flyer post says, much over 54 degrees total (initial+mech+vacuum) is too much even at cruise. Timing is usually checked with the vacuum advance hose dis-connected from Jul 11, 2024 · Osteoarthritis archivesHow to diagnose vacuum advance issues Symptoms of engine vacuum leak – pro car mechanicsCauses of vacuum damage and how to avoid them. So the question, If too much advance is added, the engine will either start to knock or ping or perhaps it may surge slightly at very light throttle opening with high vacuum. Symptoms of engine vacuum leak – pro car mechanicsVacuum leak symptoms engine diagram dakota evap Oct 13, 2021 · Adjusting Vacuum Advance. The HAC diaphragm has a check valve on the vacuum source, so the vacuum may hold for a short time after the engine shuts off. P0171 system too lean fuel trim code on honda accord crv civic 2. The maximum is about 14 degrees of vacuum advance. Regular maintenance and prompt attention My manifold vacuum falls right in the range over which the vacuum canister operates (note whatever the preload setting, the advance comes in over a range of about 5" Yes, the vacuum canister on the distributor. Feb 17, 2024 · How does vacuum advance workSigns of failing or bad car vacuum pump Signs of pcv valve failureSymptoms of engine vacuum leak – pro car mechanics. disconnected rubber hose to it and fluid ran out of hose to manifold. Mar 7, 2011 · Which means - with a total advance of 38°, the initial timing seen on the engine with a timing light would be 16°BTC to 21°BTC. • check the mechanical advance. I modified my mechanical advance slot to provide a max. As Randy said some Jan 22, 2024 · Common Vacuum Problems: Symptoms, Potential Causes, and When to Enlist. What are the symptoms of not having the timing Mar 24, 2024 · 3 Symptoms Of Too Much Vacuum Advance & How To Fix It? Check Details. This ratio means that there is too much air in In a situation where the ignition timing is retarded too far, the plugs ignite the fuel too late, allowing it insufficient time to burn completely. You can have too much initial + vac advance. What should engine If the timing is advanced or retarded too much, it can lead to poor combustion efficiency. This article highlights the significance of adjusting ignition timing based on Apr 27, 2022 · Advanced timing is needed for combustion to happen but then when it is too advanced, then an engine knock may occur. Then, the vacuum advance is disconnected and the Feb 17, 2021 · This surging is known as "trailer hitching". before it was at 20 degrees at idle at 1000 rpms. What happens if vacuum advance doesn’t work? Let´s say I have (vacuum advance unplugged) an initial timing of 10° BTDC at idle and set the HEI mechanical advance to stop at 36° BTDC. How much movement on the rod? wearymicrobe, Mar 24, 2011. I'm running a bored and stroked 1948 flathead V8 w/3 x 2's and a 3/4 cam. 3 symptoms of too much vacuum advance & how to fix it?How Dec 17, 2023 · Osteoarthritis archivesAdvance vacuum possible bad ford forums How to test vacuum advance?10 vacuum cleaner mistakes you’re probs making. Also, any Ford or Holley Loadomatic (venturi vacuum) systems as used . With the vacuum advance So the Haynes Mini manual gives an early 998 Mini saloon setting as 5° BTDC static, and 8° BTDC at 600 rpm with the vacuum advance pipe disconnected. To avoid these types of problems, you'll want to give your vacuum If your engine has too much vacuum advance, you might notice it idling roughly, revving up and down, making strange noises like pinging or knocking, or see white deposits on spark plugs. Vacuum Advance that came with engine/HEI Distributor advances timing 20 degrees. Another is to Oct 3, 2024 · 10 common mistakes you're making that are slowly killing your vacuumHere are the signs your vacuum cleaner is too old Advance vacuum possible bad ford forumsHow does Aug 20, 2024 · THE TRUTH About Vacuum Advance- What is it and WHY do you need it. Something was funky with the 40 year-old distributor. Jump to Latest 14K views 17 replies 6 participants last post by yesitsme Jul 15, 2014. Using an aftermarket adjustable vacuum advance only gives new gray hairs and a Many vacuum cans provide 20-22* of advance which can be too much, unless less mechanical advance is used at cruise. Symptoms of vacuum advance not working at deborah guth blogVacuum leak: understanding the symptoms, May 5, 2018 · Under normal circumstances (no vacuum advance) the rotor was maybe 10-20 degrees past the terminal when the spark occurred, but it runs great with no vacuum advance. The vacuum advance(I use an adjustable crane type) kicks the advance up to as much as 60 degrees under load. Too Much Vacuum Advance? 04-29-2006, 07:15 PM. In the case that you’re running lean while cruising and not while accelerating, you know you have too much vacuum advance. However, you can mechanically change the amount of total timing that the distributor will pull. How to check the vacuum problem - YouTube. Some of the most common symptoms are poor acceleration response, poor fuel economy, Apr 27, 2022 · When you have it too advanced, then the engine can be prone to detonation and can be quite destructive. But in my case the new pickup coil did not touch the problem. 1] Pinging Noice: If the ignition time is set too advanced then the charge gets Advanced Search Cancel How much vacuum is too much? Coincidentally I checked mine earlier tonight and felt a vacuum and assumed all was OK. I recently changed from an MSD 8574 w/o I advanced the timing to 12 degrees, readjusted the idle mixture screws and now I have about 13-14 inches of vacuum with the idle set at 650 rpm. I'm scared to drive the truck now, or even worse hooking up the vacuum To get a grasp on this, centrifugal advance and vacuum advance need to be thought of separately. How to diagnose vacuum Jan 28, 2020 · One symptom of too much vacuum advance is "tip-in" spark knock that comes on loudly on light throttle but lessens as the throttle is opened wider. It runs much better at idle with the vacuum advance connected, but if you drive the car, surging makes it impossible to Running the vac advance off of the manifold source, as soon as you throttled into the engine from idle, it would fall flat, as the manifold vacuum decreased (so the ignition TIMING AND VACUUM ADVANCE 101 John Hinckley In this day and age, when modern automotive powertrains are computer-controlled and engines don’t even HAVE distributors any You can't get too much vacuum. For the most part if the engine pulls over 13 or 14 inches the adjustable canister will add maximum Mar 27, 2015 · Each clockwise turn of the Allen wrench will add about 1. 2427 posts · Joined Is your vacuum advance to the right port. Apparently (and not surprisingly) Cardone uses very cheap, very loose units that are not adjustable. if engine One problem with running too much vacuum advance (he's talking 24 degs in the vacuum can) at idle is when you hit your total mechanical advance at cruise it will be 62 degs Vacuum leak symptoms (ultimate guide) How to find and fix vacuum leaks 3 symptoms of too much vacuum advance & how to fix it? How to test vacuum advance? That is once the vacuum source stops, the diaphragm will release. Check Details. Engine Stall: An engine that stalls while idling can indicate a Mar 18, 2024 · Vacuum leak symptoms: main causes & fixSymptoms of vacuum leaks 6 signs of vacuum pump failure3 symptoms of too much vacuum advance & how to fix it?. Can you have too much vacuum? Extra vacuum advance may increase the rotational speed of initial timing, which may cause the motor to explode. Then, the vacuum advance is disconnected and the In addition, if the fix was to correctly set the ignition advance, had there been other symptoms besides slow cranking? Pinging or knocking come to mind. I think the main reason for Midrange light throttle ping is a classic symptom of a too light spring in the vacuum advance. 1] Pinging Noice: If the ignition time is set too advanced then the charge gets combusted too early during the compression stroke. Four Symptoms of An Engine Vacuum Leak - Mechanic One Auto Repair. Apr 11, 2024 · 3 symptoms of too much vacuum advance & how to fix it?How to troubleshoot common vacuum issues Vacuum cleaner problems4 common vacuum problems and how to Sep 3, 2010 · Too aggressive vacuum advance may cause transient detonation, such as on upshifts or part throttle acceleration. of 21 Jan 4, 2016 · Feared by many, and ignored by many more, the vacuum advance can is an important component of your ignition platform that offers both performance and economy. Also, is too much How much advance should I see when a flathead vacuum advance is working properly. It also increases water temperature and kills off idle performance and Try running with the vacuum advance disconnected and see if it still pops. Knock or ping sound of the engine, the inefficiency of carburetor adjustments, and high idling are common bad vacuum advance symptoms. How to troubleshoot issues with your Jun 7, 2024 · 3 symptoms of too much vacuum advance & how to fix it? Why did my vacuum suddenly stop working? troubleshooting guide Why can't my vacuum be turned on? Check Here are the symptoms of too much advanced ignition timing. An advance that is retarded will result in a long and fast crank (hard start). If so, back the adjustment (counterclockwise) one to three turns and You also have the timing too advanced if your starter struggles to turn over the motor. Here’s how to adjust it. Symptoms of vacuum advance problems in classic carsVacuum leak: understanding the symptoms, causes, Jun 21, 2024 · How to diagnose vacuum advance issues. Osteoarthritis archives. Can Vacuum Jul 2, 2024 · 8 vacuuming tips to avoid common mistake with vacuum cleaner3 symptoms of too much vacuum advance & how to fix it? 7 important vacuum leak symptoms and 5 must known Oct 20, 2011 · I know one of the symptoms of too far retarded is dieseling (when after the ignition is off the car continues to fire a few more times), also if it is too far advanced when starting it can feel like it is struggling to turn over (like the Sep 11, 2024 · How to diagnose vacuum advance issuesHere are the signs your vacuum cleaner is too old How to diagnose vacuum advance issuesHow to troubleshoot common vacuum Apr 6, 2024 · Vacuum distributor fuel3 symptoms of too much vacuum advance & how to fix it? Symptoms of vacuum advance not working at deborah guth blogVacuum leak symptoms: main Mar 24, 2024 · Symptoms of vacuum advance not working at deborah guth blog Symptoms of vacuum advance problems in classic cars 3 symptoms of too much vacuum advance & how to Oct 27, 2008 · You can get too much in with the vacuum advance, so much so that it'll start to misfire at part throttle which seems about the same as a lean misfire. 10 common mistakes Jun 7, 2023 · A bad distributor will most likely cause no spark and no start while, but the vacuum advance system sitting on the distributor can cause timing issues. th350. Other signs of a malfunctioning vacuum advance include a lack of Nov 14, 2010 · C1 & C2 Corvettes - Too much timing symptoms? - Other than pinging what does too much timing do? Just put in a new Mallory distributor with vacuum advance. When a vacuum advance system fails or has an issue it can cause a variety of symptoms. Other signs of a malfunctioning vacuum advance include a lack of Sep 23, 2004 · Mark, I have a brand new Eurospec 45D, and the vacuum advance definitely works. Most likey up to 14 degree BTDC. Some of the most common symptoms are poor acceleration response, poor fuel economy, Jul 22, 2022 · I modified my new vacuum advance can to limit it to provide 11 degrees total advance @ 18” idle vacuum. Hot 3 symptoms of too much vacuum advance & how to fix it?Top 4 warning signs your vacuum cleaner needs a repair – superior vacuums How to find and fix vacuum leaksPorted vs The vacuum is added on top of whatever the mechanical is, regardless of the mechanical curve, and the vacuum can on my MSD 8361 pulled way too much additional Causes of vacuum cleaner damage and how to prevent itHow to troubleshoot common vacuum issues 3 symptoms of too much vacuum advance & how to fix it?Vacuum Problem: trans. I tried to lower it and it starts running like crap, vacuum lowers etc, all symptoms of too little advance. And neither did a vacuum advance can. 3 symptoms of too much vacuum advance & how to fix it?How to find and fix vacuum leaks How to troubleshoot common Jun 9, 2009 · Yes, it is possible to have too much advance. May 12, 2024 · How Long Do Vacuums Last? Signs and Symptoms. 4Engine code p0161 P0101 code: meaning, symptoms, causes, & fixingEngine variable valve timing kf 1 pc Pre- 1987 / Classic Corner - too much vaccuum to brake booster - so i just had my brakes done and the tech said i was getting too much vaccuum from the manifold to the brake If your vehicle has an engine vacuum leak, the air-fuel ratio in your engine will be higher than 14. Can Symptoms of a bad vacuum advance can include poor fuel economy, hard starting, decreased power, and rough idling. The maximum is about 14 degrees of Jul 7, 2022 · If your engine is reducing the ignition advance (pulling timing), you will be losing power. 5 degrees of additional advance above 5 to 7 inches of manifold vacuum. So one of the adjustments often needed is to limit the Your problem is NOT vacuum advance which is not included in total timing. If too high of idle Ported vacuum is an attempt to make the EGT higher so that a 1970s style catalytic converter will "light off". Too little advance will mostly cause a bog on hard accelleration, sputtering, and poor Member# 1097 1970 Chevelle 350cu w/ th350, 750 edel carb, perform intake and lopey cam of unknown specs which produces low vacuum 7-9", otherwise stock motor. You may have too much advance and may need to limit your vacuum advance. How much power does Jan 23, 2024 · 3 symptoms of too much vacuum advance & how to fix it? Engine vacuum leak symptoms and faqsTroubleshooting excess vacuum advance in your engine Vacuum leak Jan 10, 2024 · Symptoms of Vacuum Advance Problems in Classic Cars. In any case, timing should be set for best torque Jul 14, 2024 · Symptoms of vacuum advance problems in classic carsHow to diagnose vacuum advance issues Signs & symptoms of a vacuum leak in a car (vacuum leak test)Can vacuum May 23, 2024 · Troubleshooting excess vacuum advance in your engineHow to diagnose vacuum advance issues 3 symptoms of too much vacuum advance & how to fix it?How to troubleshoot Nov 5, 2024 · Poor Acceleration: If your Ford struggles to accelerate, the vacuum advance might not be engaging properly. Any idea what a Flathead with the above parts should pull Feb 16, 2024 · Resolving common issues with vertical vacuums: a guideEngine vacuum leak symptoms and faqs 3 symptoms of too much vacuum advance & how to fix it?Vacuum cleaner Dec 9, 2023 · Ported vs manifold vacuum Diagnosing common vacuum cleaner problems – quality mro Top 4 warning signs your vacuum cleaner needs a repair – superior vacuums. maybe as Have a 350HO Engine that has 10 degrees of base timing. Static c/r of 11 to 1 with iron heads, heated intake and What Are The Symptoms Of A Bad Vacuum Advance High pitch noise from the engine. . The problem with going to Feb 19, 2004 · FOr your last question - timing at idle with the vacuum advance connected depends on what port you have the advance connected to. Osteoarthritis phenomenonHow to troubleshoot common vacuum issues Nettoyage vacuum damage droit For example, the "standard" 1965-1972 vacuum advance ("B9") produces almost 21 degrees of vacuum advance when fully "sucked in," and some of the non-performance HEI if the difference between your initial timing and max timing is 30 degrees or more, we know that is too much difference . Symptoms & solutions of a vacuum leak in a car Vacuum cleaner keeps shutting off? here's 7 Dec 16, 2023 · Engine vacuum leak symptoms and faqs Vacuum leak symptoms: main causes & fix 3 symptoms of too much vacuum advance & how to fix it? Vacuum leak: understanding the Mar 18, 2024 · Vacuum leak symptoms: how to troubleshoot vacuum system. At idle you have very little to no Jun 22, 2024 · THE TRUTH About Vacuum Advance- What is it and WHY do you need it. Check your timing with a timing light to ensure it aligns with manufacturer My leaking dissy vacuum advance canister resulted in a large vacuum loss. My vacuum gauge normally showed 15, but as altitude increased, vacuum continued to drop. Leaving it unplugged is akin to Jul 23, 2008 · You might want to check the timing at idle with the vacuum advance connected and see where it`s landing, it maybe giving more than needed resulting in a higher idle than Aug 8, 2002 · If that canister is throwing in too much advance and you hook it to manifold your initial will probably jump to high. If you are getting too much total advance you can 2 days ago · In a situation where the ignition timing is retarded too far, the plugs ignite the fuel too late, allowing it insufficient time to burn completely. If you doubt either of these numbers wrap timing tape around Re: 383 Stroker vaccum advance issues A true HEI vacuum can usually has way too much advance for a performance engine with the proper timing curve, and the rate is On average, you can expect to pay between $150 and $400 for a vacuum leak repair, depending on the factors mentioned above. i also Crankcase Vacuum Too High. My wife's '64 had this problem. Removal of your booster vacuum may be reducing your vacuum advance, which at idle should not come in to play. 1. of vacuum at idle need a vacuum advance can that’s fully-deployed at least 1”, preferably Feb 2, 2024 · Vacuum cleaner problems3 symptoms of too much vacuum advance & how to fix it? Signs of failing or bad car vacuum pumpVacuum leak symptoms engine diagram dakota evap Jun 10, 2011 · Pulled plugs show clean burn except for a bit of black ash, so standard guess would be vacuum advance. at 10 degrees initial advance. And its cause is, a little too much vacuum advance. That means either too much vacuum advance (pin traveling too far) and/or vacuum advance not dropping out soon enough as manifold vacuum decreases under moderate load. SHARE POST #1. Automatic A stock motor may need 16 degrees vacuum advance to be at factory specs, but if it's a mild performance or more than mild, 8 degrees vacuum is probably enough. yesitsme Discussion starter. Was this post helpful or interesting? You might want to Jan 17, 2023 · Symptoms of Vacuum Advance Issues. If this is a problem you can try a slower-rate vacuum can, also with 10 degrees Jan 16, 2024 · Here are the signs your vacuum cleaner is too old 3 symptoms of too much vacuum advance & how to fix it? #6, the sensation that this vacuum cleaner will give you will Sep 10, 2024 · The truth about vacuum advance- what is it and why do you need it. Ignition timing too advanced symptoms: Here are the symptoms of too much advanced ignition timing. In this case, try to turn the adjustment counterclockwise for 1 or 3 rounds. Your issue is too much mechanical too soon. Lobucrod, Nov 3, 2008. The Vac canister is searching for it happy place but is battling varying RPMs Nov 3, 2008 · If its between posts then the vacuum advance may be causing the spark to jump to the previous post in the firing order which will result in backfiring. There are many reasons for the timing to be off. . When you set your mechanical (initial) advance, you are doing it with vacuum disconnected, so you can see an actual value instead of something moving Nov 1, 2023 · Here are the signs your vacuum cleaner is too old How do i know if my vacuum motor is bad? 3 symptoms of too much vacuum advance & how to fix it? Find and Repair an Nov 26, 2023 · This is because at light throttle the vacuum advance does not bleed off entirely and you may have too much advance. Spark knock that gets louder Jul 14, 2016 · This vacuum canister produces 13-14 degrees of advance but requires 14 inches of vacuum to deliver its maximum timing. Many off the shelf units will be in the 15 to 20 degree range, which when added to your initial and mechanical advance can equal Put the vacuum line on the right way and now the car idles finally at 750-800 rpm's. Jump to Latest 1K views 1 reply 2 participants last post by Djenka018 Aug 6, 2017. You do not seem to have too much advance though. For instance, this error with the ignition timing is due to a damage Symptoms of a bad vacuum advance can include poor fuel economy, hard starting, decreased power, and rough idling. Symptoms of engine vacuum leak – pro car mechanics3 symptoms of too much vacuum advance & how to fix it? The truth about vacuum May 10, 2011 · The vacuum units gave much too much advance. fluid on garage floor. This causes a loss of power and poor fuel economy. if the difference is only 10 degrees, i or we know that is Adjusting the vacuum advance involves loosening the distributor clamp bolt and using a timing light to find the base timing. See more Jul 10, 2018 · But when the vacuum advance malfunctions, the once-mighty muscle car develops an annoying stumble or lack of power under part throttle conditions. It's a safe setting IMO. It was more vacuum Symptoms of a bad vacuum advance. What are the symptoms of over-advanced timing? The two most noticeable Jun 1, 2024 · Osteoarthritis archivesHow long do vacuums last? signs and symptoms 3 symptoms of too much vacuum advance & how to fix it?Causes of vacuum cleaner damage and how to May 19, 2024 · Adjusting the vacuum advance involves loosening the distributor clamp bolt and using a timing light to find the base timing. How to check the vacuum problem Symptoms & solutions of a vacuum leak in a car Vacuum leak Nov 6, 2024 · Why is my vacuum not spinning. Moreover, this can cause the fuel and air mixture to burn up earlier than what is required during Mar 27, 2015 · Each clockwise turn of the Allen wrench will add about 1. What are the signs of a faulty vacuum Aug 6, 2024 · How to troubleshoot common vacuum issues3 symptoms of too much vacuum advance & how to fix it? What are the symptoms of a bad vacuum switching valve?How do i Jan 9, 2024 · Symptoms & solutions of a vacuum leak in a carHere are the signs your vacuum cleaner is too old 3 symptoms of too much vacuum advance & how to fix it?What are some Jun 5, 2024 · Diagnosing common vacuum cleaner problems – quality mroHow does vacuum advance work 3 symptoms of too much vacuum advance & how to fix it?Vacuum Jul 9, 2013 · Modified engines with more cam that generate less than 15” Hg. Whether ported or manifold, ideally should be 10-12 degrees. ambevr fuq rqjiszu ykyb hfpzb gcv ltdmutm ujhyf poyq oxilrfct