426 still missing after an inframe overhaul
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=141944
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Topic: 426 still missing after an inframe overhaul
Posted By: Commonwealth81
Subject: 426 still missing after an inframe overhaul
Date Posted: 29 Aug 2017 at 7:44pm
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First post here but I figured some of you guys would be more familiar with this motor. I drug an 8030 out of a barn that has been sitting since 2004 and don't have any idea of how it was running when it was parked. I decided to do the overhaul because it only had 50psi of compression on #1 and #3.. so, after I tore it down I found lots of broken rings. Went ahead and had injectors tested and a valve job done on the head also. I got it all back together today and fired it up but it's running very rough and seems that #1 is hardly doing anything. So, I swapped #1 and #6 injector and the miss stayed on #1.. I then did a compression test on #1 and #6 and they both were at 200 psi.. I'm thinking I got pump problems but it seems odd that a rotary pump would pick just one cylinder to act up on? Maybe because it sit so long in that spot that something rusted around that port in pump? I also checked the timing and it is only set at 10 degrees which is way low but I don't think it would cause it too run rough? Has anyone seen a ambac pump act like this? Sorry for the long post. Thanks |
Replies:
Posted By: Orange Blood
Date Posted: 29 Aug 2017 at 9:36pm
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I agree get your pump R&R'd Look up Injection Pump ED ------------- Still in use: HD7 WC C CA WD 2-WD45 WD45LP WD45D D14 3-D17 D17LP 2-D19D D19LP 190XTD 190XTLP 720 D21 220 7020 7030 7040 7045 3-7060 Projects: 3-U UC 2-G 2-B 2-C CA 7-WC RC WDLP WF D14 D21 210 7045 N7 |
Posted By: injpumpEd
Date Posted: 30 Aug 2017 at 7:37am
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A miss on one cylinder is probably not the pump, unless something in the hyd head is eroded away. Very unlikely. 200 psi is not nearly enough for a diesel. Should be at least 300, but 350 is better. Comp test another good cylinder. Maybe your gauge is just not accurate. You want to check the pump, take the injector out, turn the injection line away from the engine, or get a spare line, and put the injector on the line, and see if it will pop the injector while hanging on the inj line. ------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: Commonwealth81
Date Posted: 30 Aug 2017 at 8:57am
| Ok, thanks I may and see if I can rig something up to watch it spray. It probably has more than 200 because my tester has a flat bottom and the injector hole in the head is beveled. I could see and hear a lot blowing out around it on the test but I figured 200 was enough to fire the hole. |
Posted By: Commonwealth81
Date Posted: 30 Aug 2017 at 9:24am
| I did set the valve lash at .15.... with engine hot, those are the specs that came with my overhaul kit. Does that sound right? |
Posted By: DrAllis
Date Posted: 30 Aug 2017 at 12:05pm
| Much easier to do .017" COLD and throw the valve cover on and be done with it. |
Posted By: JC-WI
Date Posted: 30 Aug 2017 at 12:32pm
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Ciould it be a cam lobe wiped? ------------- He who says there is no evil has already deceived himself The truth is the truth, sugar coated or not. Trawler II says, "Remember that." |
Posted By: LeonR2013
Date Posted: 30 Aug 2017 at 3:19pm
| Naw, that would mess with his comp. some. Loosen the line at the inj. and spin her over real good. I know, it'll make a mess so pick a good spot to do it. I think you ought to check the pump pressure. You know, it could be the cam. Is it a dead miss, or just sorta loapy? I'd pull that line and see if you can get air thru. it too. |
Posted By: bigal121892
Date Posted: 30 Aug 2017 at 8:49pm
| This is kind of a long shot, and doesn't completely fit the symptoms, but I have had problems with the 426 engines, cracking exhaust valves, after having a head done. Whenever I had a head worked on, we always had the exhaust valves replaced. |
Posted By: Peterson
Date Posted: 30 Aug 2017 at 10:04pm
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Prolly not what's wrong with it, but did you put the injectors I the right way? Return line is towards the valve cover. ------------- 7095-685I at 255hp, 8070-225HP,8050-210Hp,8030 with 155HP,220 with 670T engine with A-pump, 7580, 185 with 140HP, 2-6080's,6070, S4 D17,wd45,CA,st34 agco, S1 D17 with 3500MK2 |
Posted By: bill2260
Date Posted: 31 Aug 2017 at 10:15am
| Make sure you put washers on bolts that hold injectors in place. After a neighbor overhauled my 185 he left washers off one cylinder and it would miss. He figured out the problem. Put washers on drawled up tight and it worked fine. Bill |
Posted By: Brian Jasper co. Ia
Date Posted: 31 Aug 2017 at 5:44pm
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A cylinder leakage test would tell for sure where it's going. I don't know for sure what a 426 should be for compression, but Duramax and Powerstroke won't fire at 300 psi. A good one in that case will be right at 400 psi. What are the known good cylinders reading for compression? Couldn't hurt to compare the rocker arm movement or even put a dial indicator on each arm and bar it over. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: LeonR2013
Date Posted: 31 Aug 2017 at 7:05pm
| That would let you know if the cam is going flat. |
Posted By: Commonwealth81
Date Posted: 31 Aug 2017 at 8:15pm
| Just figured I would update since I am getting replies. It doesn't make sense to me but I set the pump Timing up to 20 degeees and it cleared up and runs smooth with no smoke. I am happy as hell but doesn't make sense. Maybe #1 was hitting better than what I thought and it was a little miss from all cylinders. It was set at 10 degrees when I checked it. I was sure that it wasn't going to fix it but I wanted to set it correctly just to see. |
Posted By: injpumpEd
Date Posted: 01 Sep 2017 at 7:34am
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being off time is a huge deal to a diesel. Spec is 19*, and I'd rather see one timed slightly advanced in stead of retarded. ------------- 210 "too hot to farm" puller, part of the "insane pumpkin posse". Owner of Guenther Heritage Diesel, specializing in fuel injection systems on heritage era tractors. stock rebuilds to all out pullers! |
Posted By: tornado8070
Date Posted: 01 Sep 2017 at 9:26am
I have seen one set at 14 degrees and it sounded like  . 19-20 and it purrs lik a kitten! ------------- 09’ DT205B, 08’ DT220A, 83' 8070 MFWD, 83’ 8070 85’ 8050 MFWD, 83' 8030, 82' 8010, 85’ 6080 MFWD, 84’ 6080, 79' 7020, 85' M3 RWD, 85' 920 diesel,AC C-50 forklift. |
Posted By: Kevin in WA
Date Posted: 01 Sep 2017 at 10:27am
| Your headgasket will live better if it is timed at 18 That being said the intravance has to be working correctly for it to burn clean, a lot of times a worn pump wont advance correctly and will make it smoke and run hot and sound like crap. When it comes down to it these AMBAC 100 pumps are a POS. I have 2 8070s one with an AMBAC and one with an A series inlne on it, both set to about 180 HP and there is no comparison between the two tractors when it comes to governor response. The AMBAC has to have a 2-300 rpm droop to get full fuel, the inline only needs about 50. And the inline will probably run for 10,000 hrs vs 3000 hrs from an AMBAC. |
Posted By: LeonR2013
Date Posted: 01 Sep 2017 at 7:53pm
| How bout that. Thanks for letting us know. |