LUVTruck.com

OK So I've owned this truck awhile now. Baught it 2 years ago. It was completely stock exept the dash and the seat:) I've replaced a few small things, water pump,belt,thermostat,hoses, engineered a new front end.. Was running great#*;!! Then one day doin about 35 wham, shaking and shuddering would barley do over 15 in 4th.. You can hear the fuel pump running. But I changed the filter anyway, added some thickening stuff to the already 20/50 oil. (Colorado)btw. And everything seems to help it a little. But the I pull it in the shop and lift it off the ground to take a look from the underside and in the air its idle is fine:\ I was so lost. On the ground it would barley keep coughing. I ran some cleaner in the oil then changed it added some zinc , and ran some bg44k in the fuel also. Ran much better. Went ten mikes to the next town and back and then parked it for 2 months, I just didn't have time. Anyway pulled the plugs yo find oil on my 4th cylinder plug. And havnt looked at it again for another month until today. And it fired right up!! Still shakey but nothing like it was. I'm so lost.... any ideas would be super appreciated it just seems like nothing adds up.

Make sure your valves are adjusted properly, then bring it up to operating temperature and do a compression test. Sudden major loss of power coupled with running rough is often either a burnt/cracked valve or blown head gasket.

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'78 Chevy LUV,1.9,4sp,headers,31's,SAS Dana 30,Dana 20,SOA rear w/Aussie Locker, rough body, bought new 12/4/78.
'87 Trooper,2.3,5sp,headers,31's,ball joint flip & spacer,Aussie Locker rear,Superwinch hubs,brush guard w/5.5K winch,more to come.

Thank you. That's deeper than my current mechanical experience has taken me. But I was thinking that maybe the valve seats were worn and that's why these things seem to be helping it?

My first guess would be a cracked valve like isuzuist said. Careful getting the head bolts off!

Good luck!

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Hannah - '79 4WD, 32/36 Weber, and a Pacesetter header.

head bolts should come off and go on in a pattern so if you attempt to do this get a manual so you know

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Previously owned 2 Luvs) 75 & 77 Fleet-side
3rd 77 Step fixing up aka The Yellow Submarine to Luv Ms (Sun)Shine=)
98 GMC Gas Guzzler~>The reason 4 my ~>3rdLuvNext2a66MALIBU =)
66 Chevelle The Oldest of all the vehicles I owned

Where are you located?

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Luvless
1980 Mikado-Sold.

1993 Lexus SC400 my Daily
2004 Yamaha WR250F my new love in life
2016 Toyota Camry my girls ride

Glenwood springs colorado.! I believe that the valve burnt up because of no leaded fuel. But I just haven't gotten around to tearing it apart. I have a great machine shop here I should just fix it. First 200$ takes it haha.

We haven't had lead in many years in California, I haven't seen a burnt valve do to no lead around here in a LUV.

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Certified pilots, looking down on people since 1903.

First thing I did to my 78 when I got it was take off the "Unleaded fuel only" sticker above the gas cap.

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Click on C.M. logo to go to my webpage


RIP R.J.B.