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Hey everyone! Ok, I have a massively bad surging, bucking problem through all gears, under load. Decelerating there is no bucking. The surging is uniform even in neutral. I'm thinking it's a TPS, ignition timing problem, or fuel pump problem? The engine is b20e. I checked for any vacuum leafs around hoses to manifold and distributor, and anywhere else and couldn't find any loose hoses. Any thoughts and help is greatly appreciated!
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posted by
someone claiming to be Blackjackmc
on
Thu Apr 17 14:30 CST 2014 [ RELATED]
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Without a timing light you have no idea of initial timing or total advance. Before pulling pertronix bring revs up to about 3000 rpm and hold it there then slowly advance distributor until you feel a miss come in then retard until it smooths out. Lock dist this will be somewhere near total advance. I assume firing order is in direction of rotation. If this makes a difference you can rule out fuel system.
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posted by
someone claiming to be Blackjackmc
on
Tue Apr 15 16:16 CST 2014 [ RELATED]
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First off disconnect vacuum hose to advance diaphragm. If miss varies breaker plate that carries points would be worn and varies points gap and dwell when vacuum activates breaker plate. Another check would be points cam frozen to dist shaft. Plug leads can break down under load if too far advanced.
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OK, so by my description, the problem sounds like the engine is misfiring? Maybe I should check the plugs too? If the trigger contacts are dirty, what do i clean them with?
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Yep, check the plugs, points, distributor cap, etc., etc. - all things related to ignition. If the plugs are questionable, pop in some new ones. They're only $2.00 each.
The contacts in the TPS can be cleaned with alcohol and some people use an ink eraser to clean them. The ink eraser is just barely abrasive enough to clean the printed contacts without completely tearing them up. The trigger points can be lightly filed or cleaned up with fine sand paper just like you would do with the ignition points. I've found the easiest way to check the trigger points is to pull the distributor out of the car. If you only remove the bolt that holds it into the engine, and don't loosen the pinch bolt above it, you won't lose your timing. Once the distributor is on the bench, it's much easier to connect an ohm meter to the contacts and spin the shaft in order to see approximately how many degrees of dwell each of the contacts has. If you find that the trigger points are barely breaking for just a few degrees of rotation, you can pull them out of the distributor and tweak the stationary side of the points to give you more gap (or more degrees of "open").
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OK, so it turns out that I had a b20f dizzy with a Pertronix module in it. I decided to swap it into the b20e block and see if it worked any better. First start, the idle was so rough, it stalled out and quit. I decided to try to set the ignition timing by wrenching the crank to 10 deg. BTDC (I assumed the descending 10 mark next to the zero was 10 BTDC). While wrenching the crank over, I had the spark plug out and the oil cap off. I heard the whoosh sound of the compression stroke and both valves for #1 cylinder looked closed. After I set the crank, I rotated the notch on the edge of the dizzy to point towards #1 cylinder. I clipped on the cap, connected the vacuum advance hose from the intake back onto the advance diaphragm. Now, the car runs better but idles around 1.1k-900 rpm, the misfiring has stopped but it still feels slightly rough to drive.However, before this attempt to set ignition, the car was downright undrivable. I think I'm going to try and swap in the original b20e dizzy once I have installed a pair of points. I also want to carefully disassemble it to inspect for badly worn parts. Could I anyone recommend tools and chemicals to help me carefully restore it? Also, should I just set the crank to "0" ( TDC )? Thanks for taking the time to respond!
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First step is to simply install it and see if you can get it to moove smootly from 10° to 34° relatively smoothly with your timing light on Number 1. If good, try it on 4, should be the same. I like to put marks on my pulley 180+° for numbers 2&3. Set the points to .014", forget the dwell meter as they are completly useless.
Condenser(Capacitor): If you have a good one, don't ever swap it out, leave it be and just carry a spare set of points & condenser. One job a condenser does is to stop the points from pitting. Points pit in one direction or the other depending on the microfarads of the condenser, when you get a good condenser with bang on correct microfarads, you will find the face of the points won't pit & the gap will stay constant until the rubbing piece wears down, easily 25,000 miles.
Do the springs feel like they are working in the electronic dizzy?
--
Three 164's, Two 144's, One 142 & a partridge in a pear tree.
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I don't know how to tell if they are working, or whichever springs you are asking about. The car does feel like I may have slightly dulled the power, after installing the b20f's pertronix equipped dizzy; it's not bad but it feels slightly different. Thank you for the additional advice. I'll be taking it into account when I have time to tinker, tomorrow. I'll try and update this thread with what I've learned.
Today I spent all my time fixing the driver's side window regulator, which was good because it rolls up, now.
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If a dirty or worn TPS were the problem, it generally first shows up when the throttle is somewhere around the half-open position - approximately where it is when you are cruising on level road and not so much at idle or full throttle. If you are experiencing a miss under load at ANY throttle setting, I would first suspect the ignition. That being said, it costs $0 to open up the TPS and clean the contacts. If it looks like the contacts have worn a bad path across the printed board you can carefully tweak the contact to track across the board on a fresh path.
Another area to check is the dwell on each of the two trigger points. There exact amount of dwell isn't "highly" critical. You just want to be sure they are opening. I generally shoot for about 180 deg open / 180 deg closed, just to be sure.
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OK, so things I have checked: Electrical connectors at Pressure Sensor, injectors, TPS, Coolant Sensor. I checked the ground wires for the fuel pump relay, fuel pump, intake manifold ground at the thermal timer, and the vehicle ground the connects to the flywheel housing. I checked the plug wires, plugs (which are not soiled or eroded), rotor(doesn't look too worn), and cap.
As far as trigger contacts are concerned, I don't think there is anything wrong with them because I got the same problem with two identical distributors, and one of them has the pertronix module in it. The one with the pertronix module came from a my previous 142e, which never had the same symptom.
I'm starting to suspect the problem lies in the gas tank. I don't know what condition it is in and I'm starting to notice tracer fuel leaks all around the perimeter of the underside of the tank. Is it possible for back pressure to build up in the tank, restricting flow of gas? If so isn't that incredibly bad for the fuel pump? I have not yet checked the fuel pressure by hooking up a pressure gauge between the cold start injector and the fuel rail, which is what I'm going to do today. When I do that, I'm going to use one of those multi-purpose pressure guns that you can also use for doing brake bleeds. I'm sure you guys know what I'm talking about, do you think that's a proper type of gauge? How exactly do I check the fuel pressure?
Another suspicion is that I know there is a vacuum leak coming from the exhaust manifold, there's a definitive whistling sound during the exhaust stroke of cylinder 1. Also, I'm reading that an intake manifold vacuum leak could also cause misfire-like symptoms. The PO disconnected the vacuum hose from aux air valve to the intake and plugged the aux valve. He also, installed a k&n filter and by the looks of it, must have hacked up the silicon rubber connecting hose to fit it onto the intake, then clamping it with a hose clamp. Also, could an overly dirty air filter cause misfire-like symptoms?
Thanks for your time to read this exhausting thread.
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