8070 Hard starting
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=163458
Printed Date: 08 Sep 2025 at 4:45pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 8070 Hard starting
Posted By: Gregor
Subject: 8070 Hard starting
Date Posted: 07 Aug 2019 at 3:38pm
| Hi Guys, my 8070 looses prime after sitting for a day. Probably closer to losing prime after sitting about 5 hrs and seems like it is getting worse. Use to be about 3 days of sitting before you had to crank it alot. There is no smoke coming out of the pipe for probably 7-8 secs and then runs like it is short on diesel for the 20-30 secs. It has been this way for about 10 years. Last summer, I overhauled the motor, injector pump rebuild at Beemer Diesel (very reputable), checked injectors and good. All seals on the lines have been replaced during the overhaul. No leaks. Filters changed yearly which is about 50 hrs max. New batteries and cranks fast or like it should. All this had zero difference on it and maybe even got worse. It doesn't matter is the tank is 3/4 full or nearly empty. Once started, runs great and power as advertised. With cooler weather coming, it will crank longer to start. I have a holley electric fuel pump on a parted out N5 that I was going to install on the hose from the bottom of the tank. Maybe that will show a leak on the suction side?? Will I hurt anything installing that pump on it pemanently. I think it is a 5 gpm. What am I missing? Tractor has about 5500 hrs on it and I've had this tractor since nearly new. Thanks Greg |
Replies:
Posted By: 210Postin
Date Posted: 07 Aug 2019 at 9:21pm
| Well it is about 25 dollars to replace the hose from tank to filter to filter if i remember it is half inch fuel hose and use new clamps |
Posted By: MACK
Date Posted: 07 Aug 2019 at 9:26pm
| Debra in check valves on primer. Check vent on fuel tanks. MACK |
Posted By: randy
Date Posted: 08 Aug 2019 at 7:51am
|
Mine does the same, except when its full it starts, about 3/4 full it starts fine. I have replaced every fuel hose on it and checked the hose on the return line inside the tank. I will try the primer and the tank vents next. Thanks for the info. Randy ------------- CA WD WD45 D17 D17 Diesel 7060 8050 8070 |
Posted By: Peterson
Date Posted: 08 Aug 2019 at 8:06am
|
Do you guys have the updated fuel return line that goes into the tank? Had the same problem with our 8030. Fixed it right up. ------------- 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: Ron(AB)
Date Posted: 08 Aug 2019 at 8:34am
|
What is the difference with the updated fuel return line? Should every 8000 series have it? |
Posted By: Peterson
Date Posted: 08 Aug 2019 at 8:40am
|
The first 8000 series just had the return into the top of the tank, the later ones and updated tractors have it go into the top of the tank with a tube that goes to the bottom of the tank. That way it doesn't drain the return line along with the head of the pump. Yes all should have the update done. Ill get you guys a scan of the factory update sheet. ------------- 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: Leon B MO
Date Posted: 08 Aug 2019 at 9:54am
|
I bet I've got two 80xx tractors that need this update. Never new anything about it but now I think I'll take a look at the return line in the tank. Thanks Leon B Mo ------------- Uncle always said "Fill the back of the shovel and the front will take care of itself". |
Posted By: Gregor
Date Posted: 08 Aug 2019 at 10:21am
| Figured it was the return draining away somehow. Priming pump is new with the injector pump overhaul as it is on the injector pump. Breather vent is good also. Curious too on the return line fix. |
Posted By: Peterson
Date Posted: 08 Aug 2019 at 11:21am
Here ya guys go.  ------------- 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: SteveM C/IL
Date Posted: 08 Aug 2019 at 12:55pm
| sounds like my 84 model has the "correction" |
Posted By: Ron(AB)
Date Posted: 08 Aug 2019 at 1:15pm
| Thanks for the info! |
Posted By: randy
Date Posted: 08 Aug 2019 at 5:04pm
|
Mine has the hose in it. Going to check the pump for debris in it. ------------- CA WD WD45 D17 D17 Diesel 7060 8050 8070 |
Posted By: Kevin in WA
Date Posted: 08 Aug 2019 at 5:16pm
| A lot of times that plastic tube falls off and is laying in the bottom of the tank. |
Posted By: randy
Date Posted: 08 Aug 2019 at 5:54pm
|
Inpumped, chime in on this! ------------- CA WD WD45 D17 D17 Diesel 7060 8050 8070 |
Posted By: Andrew(southernIL)
Date Posted: 08 Aug 2019 at 8:28pm
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Our 7000 tends to do this as well but I assuming it has to do with the small fuel leak im seeing on the injection pump ------------- If fishing is a sport your looking at an athlete |
Posted By: injpumpEd
Date Posted: 09 Aug 2019 at 8:33am
Looks like it's being handled plus I learned something. I as a pump re-builder, hate on engine plumbing issues! They are almost as hard to diagnose as electrical gremlins! ------------- 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! |
randy wrote: