Engine breaking up or surging?? I'm confused
A new problem has developed on Frankentruck this weekend.
On Wednesday, I took a trip back to Milledgeville and the truck did fine. No issues, nothing to be concerned about. On Thursday, I went full throttle up through the gears and noticed it started breaking up a little above 3k rpm in 2nd and then continued once I shifted into 3rd. Didn't do it the rest of the day, but I also didn't drive hard or go much faster than 50. On Friday, I drove back home. It was Friday afternoon, so I chose not to take the interstate and deal with Atlanta traffic. I took mostly 2 lane highways and going up a hill in overdrive, doing about 60, the engine started surging or breaking up. Basically, it would miss on a couple cylinders, then fire strong on a couple others and make the truck buck like a horse. It also slowed me way down and didn't want to recover until I was able to pull off the road. I didn't see anything particularly out of whack under the hood. I didn't shut the engine off, and it was idling like normal, so I continued on. It kept happening if I would give too much throttle going up a hill for the rest of the trip home, but once I could reach the top of the hill, it would stop and I could accelerate back up to speed. So, have any of y'all experienced something like what I'm describing? I'm thinking I should look at either the fuel pump, which is the mechanical pump that was on the truck when I bought it, or the ignition module, which is unknown to me as I did not replace it when I swapped to the HEI. Engine is a 283 small block, Quadrajet with an electric choke, HEI dizzy, and 3 speed manual with overdrive |
Re: Engine breaking up or surging?? I'm confused
I would check in order...
Fuel filter getting clogged Fuel cap not venting Bad HEI module Poor engine ground wires to chassis and engine Faulty fuel pump When you put the HEI in, did you remove the resistance wire power feed and replace it with standard wire? The HEI needs full 12 volts to the module. The resistance wire used on old points systems drops this down to 9 volts to slow the burn up of the points. :chevy::chevy::chevy: |
Re: Engine breaking up or surging?? I'm confused
If it’s not the filter it’s likely the pump.
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Re: Engine breaking up or surging?? I'm confused
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Here's what the filter currently looks like. I replaced it a couple months ago and it didn't look crushed like that. I haven't had any issues with noticeable chunks of trash floating around in the fuel filter in a long time. Also, I've always had an inline filter before the filter in the Quadrajet.
I did remove the resistance wire when I installed the HEI |
Re: Engine breaking up or surging?? I'm confused
What does the filter in the Quadrajet look like? Plug wires in good shape? Has the timing maybe changed because the dizzy possibly rotated (slipped) in the hole?
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Re: Engine breaking up or surging?? I'm confused
Change that fuel filter as its pleating is collapsing and will slow down fuel flow.
Check the filter in the Quadrajet, Remove the inlet fitting and if the filter is paper, replace it....if its an old bronze style filter, replace it with apaper filter and spring. :chevy::chevy::chevy: |
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I'll also check the plug wires and see if the dizzy has moved, thanks. Quote:
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Re: Engine breaking up or surging?? I'm confused
Some inline filters have a direction arrow. If that one is flow direction sensitive and was installed backwards, could explain why it is collapsing.
Had a lot of rain/humidity? Maybe some water in the gas. |
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There's always some humidity in GA, but I've never had this issue before this weekend, and the weekend was fairly dry up until today. It's been raining all day today, so I haven't had a chance to check anything |
Re: Engine breaking up or surging?? I'm confused
I haven't had a chance to check on anything yet, but I wanted to drive the truck today and did a couple tests. I can rev out to 4k+ rpm in 1st gear with no problem, but then when I grab second and continue up to 4k+, it starts to do the funky thing. Couldn't get into 3rd because I didn't go out on a highway. Because of that, I'm leaning more towards a fuel issue rather than ignition.
I'll be replacing that fuel filter tomorrow |
Re: Engine breaking up or surging?? I'm confused
Change the one in the carb also. They still clog up even with the inline filter. Evidently they filter to a smaller particle.
George |
Re: Engine breaking up or surging?? I'm confused
Good luck on the filter change. I hope that's it. If not, consider the pickup in the tank. I know my '70 has a sock on it, but not sure about the earlier tanks. You had mentioned crud from the tank.
EDIT: Just checked the online images for '63 C10 tanks and there is a sock. |
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Re: Engine breaking up or surging?? I'm confused
When you pull the fuel line apart for the filter, put the end of the line in a quart jar and crank it over.
Normal pump should have a strong shot of fuel and fill the jar in 30 seconds. |
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Re: Engine breaking up or surging?? I'm confused
Thanks, y'all for your suggestions and places to check. So after testing the fuel pump and it checking out ok, I decided to test the ignition coil since it's easier to get to rather than the control module under the cap.
So I measured the ohms on the primary winding and got 1.2 at the lowest. The secondary winding was ok at 8k+. From the research I've done, the primary should be anywhere between 0 and 1. So any recommendations on what coil I should get for a mostly stock 283? I think I'm also going to pick up a control module just in case it's both |
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If you had an ignition problem, it wouldn't matter which gear the transmission is in when the problem crops up.. I agree with about 90% of the posters in this thread --- You have a fuel delivery problem.. I'd be looking for a faulty fuel pump, a restricted filter, rubber fuel lines collapsing under load, fuel tank not venting properly, and/or a sh*t load of other fuel delivery issues. I won't elaborate on the futility of slinging parts at a problem, hoping something "sticks".. [EDIT] Since you haven't talked about it yet, I'm assuming you haven't yet removed the filter at the carb inlet, cut either of the filters open and looked directly inside for debris???? |
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I have not cut open any filters yet, but I did find lots of small, rubber chunks that had been stopped by the filter before the carb. Because of that, I'm thinking maybe one of the rubber fuel lines is deteriorating? Either way, I'm about to run to the parts store, grab some new fuel line and filters, switch those out, then run the truck to see what happens. |
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Re: Engine breaking up or surging?? I'm confused
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Thanks again, y'all for the help!
I replaced all of the rubber lines and both the inline and Quadrajet filter. Took it for a spin around the block and was not able to make the thing happen again, even with repeated stomping on the throttle through the rpm range in 2nd. I also tried it once in 3rd overdrive climbing a hill and it didn't stumble or sputter at all. First picture shows the inlet side of the Qjet filter. Second picture shows the outlet of the same filter. I'll say it definitely did its job. Also, that filter has been in there for almost 4 years at this point because I haven't changed it since I bought that carb :lol: I'm taking the truck on a trip to Lake Hartwell tomorrow to get some parts and hang with some friends. Should I go ahead and grab a coil to have with me on the trip just in case, then return it if I don't need it? Or do y'all think I'll be fine to send it as is? |
Re: Engine breaking up or surging?? I'm confused
In other words, you're looking for an opinion. Let's look at the facts.. Every time you called on the engine for speed, carrying a load, or climbing a hill, the engine would miss and perform poorly.. EVERY TIME.. 90% of the people here directed you toward fuel starvation .. For whatever reason, it took you a week to find this filter filled and plugged with crap from the tank.. After you replaced it, the engine runs fine.. I can guarantee you still have crap in the fuel tank that will eventually make it's to a filter and that one will be plugged.. How long that will take is anybody's guess.. When it does happen, will you start this thread all over again looking for a bad coil, OR, will you go directly to the filters again.. Think about it.. With a known dirty gas tank, do you want a spare coil or spare filter????
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Re: Engine breaking up or surging?? I'm confused
Well, I shall eat my words. The problem was in fact not fixed. Didn't leave me stranded, but worked great Saturday morning with no issues, then after buying some parts and heading to my friend's lake house, it started acting up. At this point, it was warm outside. Still did the thing on my way home this afternoon when hot outside.
I can take back roads and manage the issue fairly well, but interstate driving is a no go |
Re: Engine breaking up or surging?? I'm confused
All things point at the fuel pump!
Tested or not. JMHO |
Re: Engine breaking up or surging?? I'm confused
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Well, I did an oopsie with a couple things.
First, I did not realize that the dizzy cap was missing the ground wire (middle terminal of the 3 wire plug at the coil) since I put that engine and distributor in my truck almost 4 years ago. Second, with all the testing I was trying to do, I proceeded to strip out a couple of the coil mounting holes in the cap which also led to the ground wire on the coil not being attached properly. It was too loose and I ended up frying the ignition module. Pulled the cap off the dizzy and found a lot of corrosion on the terminals and the rotor tip looked burned. At that point, I said screw it, I'm starting fresh. New cap, rotor, ground strap thingy, module, and coil went in last night. I don't know how the coil was getting a proper ground without the ground strap thingy, but I figured it wasn't quite right and probably would have led to problems in the future if I had not replaced at least that. And, yeah, that still didn't fix the initial problem, so I have a new fuel pump that should be here in the morning. Picked up a Delphi unit for $30. I'm hoping that'll be the actual fix. Ok, back to studying for my CPA exams :crazy: |
Re: Engine breaking up or surging?? I'm confused
It's quite possible that I still had the original inline 6 pump in my truck. Seems to have fixed the problem now, but I had to get some adapter fittings to make the old lines work with the new v8 pump. Also, it would have helped if I had gotten the fittings tight enough the first time :lol:
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Re: Engine breaking up or surging?? I'm confused
The inline 6 pump & the V8 pump are not the same and are not interchangeable.
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