Engine trouble on 351 PCM
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=2059
Printed Date: November-23-2024 at 12:20am
Topic: Engine trouble on 351 PCM
Posted By: '72 mustang
Subject: Engine trouble on 351 PCM
Date Posted: July-13-2005 at 2:37pm
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If anyone has any advice I would greatly appreciate it... I just bought a 72 mustang and I am having some problems with the engine. First time I took it out everything seemed ok, at approx 2500 rpm the engine sputtered oput on me. Started back up and the same thing happened again. Looked at the temp and I was around 200F. Limped back to the dock at 5mph and the engine cooled back to 160F. Checked the oil it was a little low. Pulled the plugs and #1 (front on starboard, I think thats #1)had signs of water. All others were normal (no water beads milky oil). Haven't done anything else to her since pulling the plugs. Could it be anything besides a head gasket? Maybe a bad exhaust manifold or something? Any ideas? Thanks for reading. ------------- 72 CC mustang |
Replies:
Posted By: David F
Date Posted: July-13-2005 at 2:46pm
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Cutting out at 2500 rpms is usually a fuel starvation issue. See if it happens in neutral (no load). If not, then look for several things that can cause fuel starvation:
1) Loose or ill fitting hose clamp on fuel suction line. 2) Clogged fuel filter. 3) Kink in feul suction or pressure line (if rubber) 4) Carburator float setting or carburation issues. Coil (electrical issues) usually do not start right back up until the faulty parts has cooled a bit. Not sure about your water/cylinder issue. |
Posted By: '72 mustang
Date Posted: July-13-2005 at 2:53pm
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Thanks for the tips on the fuel issues. I have checke the first three ideas, how do you adjust the float setting in the carb? ------------- 72 CC mustang |
Posted By: Guests
Date Posted: July-14-2005 at 1:10am
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It's a 351? What carb do you have? It could be a 4160 (if it's a Holley), list number 81265 (number stamped in front side of choke air horn. Does your fuel line come in from the front or from the side? If you need help identifying your carb there is info at Holley.com.
If its a universal (side fuel line) without a carburator leveling wedge plate under it then it sounds like the secondaries fuel bowl has the incorrect float level (too lean). What color were those spark plugs? 200 degree's is normal for shut down. I see that on my 87 all the time when I shut down after a run. It cools down to 170 or so when I run it up again. That's 30 degrees from lack of any water movement for cooling. 
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Posted By: Guests
Date Posted: July-14-2005 at 3:31pm
| I actually have an edlebrock carb on it and the fuel line comes in from the starboard side. My biggest concern is with the water I found in the oil. Does it mean head gasket or could it be something less severe? Oh by the way I dont have the wedge plate. From what I have read the angle could be throwing off the float level in the secondaries and causing the fuel starvation. Where could I pick up wedge plate and what is the approximate cost on one of those? Thanks for the help. |
Posted By: skyhawkflyer
Date Posted: July-14-2005 at 4:46pm
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You'll have to look back, someone did post a link for the wedge plates. Due to the position of the floats in the afb/avs series those carbs would be even more prone to leanout due to carb angle/low fuel level in float bowl.
The water in the oil sounds like A. a leaking intake maniflod gasket, or head gasket. try retorquing to see if you get any bolt movement-which would indicate a suspect gasket. B. A cracked head c. possibly a cracked intake manifold (more likely if it's an aluminum intake) but not likely. You should get that water and oil out of your engine asap before it starts creating other problems, even if the engine isn't fixed. ------------- |
Posted By: '72 mustang
Date Posted: July-14-2005 at 11:41pm
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Well, not exactly the diagnosis I was looking for but more than likely an acurate one. Before I tear the top end apart, should i do a compression check to be sure? Is there any thing else I can do to determine exactly what is wrong? I appreciate any and all input as I am a new CC owner. Thanks. ------------- 72 CC mustang |
Posted By: skyhawkflyer
Date Posted: July-15-2005 at 10:35am
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I wish I had some better news, but unfortunately there are only a few ways to get water into your oil. Maybe someone else will read this and have some idea's. I mainly know holley and carter carbs so when you get back to the carb tuning I'll help you out.
maybe check a troubleshooting guide from a chiltons manual, but I don't think I'm far aff on what needs to be done. Are your exhaust manifolds OK? ------------- |
Posted By: '72 mustang
Date Posted: July-15-2005 at 6:27pm
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thanks for your help. not sure about the exhaust manifolds. would water be able to get in the oil if they were bad? like i said before, my first course of action will be a compression test, then check to see if the exhaust manifolds are bad. maybe they could be allowing water to enter the cylinder when the engine is shut down. thanks again for your help. ------------- 72 CC mustang |
Posted By: workky
Date Posted: July-18-2005 at 2:34am
| i would ge0t water into my cylinders upon shutdown,in all of them.Turned out the riser gaskets were bad .I replaced them and no more water |
Posted By: '72 mustang
Date Posted: July-18-2005 at 1:32pm
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I am going to check those gaskets after work today even though its over 100 degrees in my garage. Hot in Sacramento lately. I am keeping my fingers crossed that my problem with water in oil is related to the exhaust manifolds or the risers. That is alot easier than tearing apart the top end, but whatever the problem is I gotta get it back in the water asap. Thanks for the info I'll be sure to check the riser gaskets. ------------- 72 CC mustang |