I just replaced the intake manifold gaskets on this car. Car ran fine, just heated up some, but ran fine. Now after replacing the intake manifold gaskets the car will fire but not stay running, even has a little backfire through the intake. What did I do wrong, I"m thinking it is a leak in the gasket, like I did not torque the bolts right or something. Right now I"m looking at taking it all back apart and doing it over. Any suggestions before I do that.
- Thread starter eremoao
- Start date
Chuck (CA)
Well-known Member
A backfire thru the intake can indicate a timing issue. Check your firing order (18436572) and also be sure # 1 is at TDC when the marks are in alignment.
HTH
HTH
Gambles
Well-known Member
Okay, I don't know if you are an expert mechanic or if you are just doing it on the side, so please forgive me if you are an expert and if you think this is a stupid question.
Here goes: The intake valve push rod and the exhaust valve push rod have different lengths on this engine. Are you sure you didn't get them mixed up?
Here goes: The intake valve push rod and the exhaust valve push rod have different lengths on this engine. Are you sure you didn't get them mixed up?
Not an expert by any means, but I made sure to replace the push rods where I took them out of. I'm going to start taking it apart down to the lower intake gasket and redo it, making sure I take my time. I had help when I did it the first time and maybe went a little to fast and didn't do something right. A waste of time but a lesson learned.
Kyle in KY
Member
Gambles is right on about the push rods. Even though I've been twisting wrench's for 30+ years, we all make mistakes. The rocker arms are not adjustable, so I'd lean towards the intake exhaust push rods may be mixed up on a cylinder. Before you tear back down, do a compression check to see if you bent a valve.
Just saying from experience (wink) an exhaust valve push rod in an intake position can bend a valve. It may idle just fine to a little rough but when you rev it up it will miss, buck, cough and spit.
The intake would have to really be loose to act the way your describing, because you can't really get the intake cocked one way or the other.
Just saying from experience (wink) an exhaust valve push rod in an intake position can bend a valve. It may idle just fine to a little rough but when you rev it up it will miss, buck, cough and spit.
The intake would have to really be loose to act the way your describing, because you can't really get the intake cocked one way or the other.
jimg.allentown
Well-known Member
All of which shows that some people will try to give a short answer - even if it is wrong - or unrelated.....
My humble opinion: Instead of short one-line answers why does nobody suggest DIAGNOSTICS?????
I have nearly preached this on this forum as well as others. Just throwing parts at the problem is the most expensive and inaccurate way to deal with ANY mechanical problem.
The man should start with the BASICS!
Compression test (before pulling it apart again).
Check and correct as necessary the firing order.
Check for vacuum lines that may have been disconnected and/or left off.
Run a scan for codes. That may point you towards something that did not get reconnected properly (like the MAP sensor on the back of the upper manifold).
A point of information.....
That particular engine has a "rat's nest" of wiring and vacuum connections on the back side of the upper manifold. Easy to get things improperly connected. Best procedure is to disconnect the "dog bone" mounts on the top front and rotate the engine forward for access.
My humble opinion: Instead of short one-line answers why does nobody suggest DIAGNOSTICS?????
I have nearly preached this on this forum as well as others. Just throwing parts at the problem is the most expensive and inaccurate way to deal with ANY mechanical problem.
The man should start with the BASICS!
Compression test (before pulling it apart again).
Check and correct as necessary the firing order.
Check for vacuum lines that may have been disconnected and/or left off.
Run a scan for codes. That may point you towards something that did not get reconnected properly (like the MAP sensor on the back of the upper manifold).
A point of information.....
That particular engine has a "rat's nest" of wiring and vacuum connections on the back side of the upper manifold. Easy to get things improperly connected. Best procedure is to disconnect the "dog bone" mounts on the top front and rotate the engine forward for access.
The thing is, I can't keep it running long enough to do a compression test. It will fire then die right away and a small backfire out the intake. I did unhook the dog bones and rotate the engine when I tore it apart. Made sure all vacuum lines and wires were connected before setting the engine back into place. I will however do it again just to verify everything before tearing back into it. The reason I'm thinking it is something I did as far a the gaskets or torques is that it ran good before I replaced the intake gaskets.
Kyle in KY
Member
Eremoao,
It doesn't have to run to do a compression test. Disconnect the power wire from the coil pack, insert the compression gauge fitting into each spark plug hole, have someone crank the engine over while watching the compression gauge. All cylinders should have close to the same reading. If one is real low or not reading at all, that is the cylinder you need to focus on.
On the back side of the intake, are you sure the brake booster vacuum line is connected? Do you hear any sucking sounds when it does start?
It doesn't have to run to do a compression test. Disconnect the power wire from the coil pack, insert the compression gauge fitting into each spark plug hole, have someone crank the engine over while watching the compression gauge. All cylinders should have close to the same reading. If one is real low or not reading at all, that is the cylinder you need to focus on.
On the back side of the intake, are you sure the brake booster vacuum line is connected? Do you hear any sucking sounds when it does start?
Thanks for all the help, got back to it today and found a vacuum line I missed. It was in the middle of the line coming from the pcv valve to the back of the motor. The middle has a line that connects to the upper intake under the venting for the air filter. Just needed to slow down and look a little closer.
Similar threads
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy