Could it be the CPS?

Mr. Red Pony · August 13th, 2010, 02:59 PM

Bent connecting rod. I just remembered that when I bent mine is was misfiring a lot. And when they took it out they did a compress test and that cylinder was about 20 PSI less. (my piston was hitting the crank a BDC though) It wouldn't put as much pressure in the cylinder because the piston wasn't going up high enough.

ESG-642T · August 13th, 2010, 03:15 PM

Originally Posted by Walters97Racing

the only tbs i see remotely related is this

NOTE FOLLOW THIS TSB PROCEDURE ONLY IF THERE ARE NO SPECIFIC MISFIRE TSBs/SSMs RELEASED FOR THE VEHICLE SYMPTOM BEING EXPERIENCED.

ISSUE
Approximately 50% of coil on plug (COP) coils returned for warranty do not have a problem.

ACTION
The misfiring cylinder must be identified through Self-Test misfire codes or through WDS Power Balance. Rule out base engine problems, rule out fuel problems, and then look at ignition problems (be sure to rule out coil primary circuit issues). Once the above steps have been completed, and the issue is in the secondary part of the ignition system, the oscilloscope procedure outlined in this TSB can isolate the difference between a coil or spark plug problem.

How does this relate? If its about anything remotely close to our cars (push rod 3.8/3.9) it doesn't have COPS.

Originally Posted by Mr. Red Pony

Possibly not a valve closing completely allowing just a little air to escape. That's my guess. But you would figure if it would let a little out, it would let all out. I think if it was the CPS it would cause it on all. Is the spark plug letting air past it? right before I blew out a sparkplug it was missfiring on that cylinder. Could be a combination of those WITH a faulty injector.. It is fuel injected right?

Valve not closing is one of the tracks I had in my mind when I said valvetrain, and it doesn't have to let all out depending on how its bent/burnt/chipped/etc.

Mr. Red Pony · August 13th, 2010, 03:23 PM

I think it is the connecting rod. Is said engine 'real'? have you seen/heard it if so?

8A_Honda · August 13th, 2010, 07:48 PM

Well, I'm sure it has to be real. He told us that one of the keypoints to remember is that it's a 3.8 liter Ford motor. So after hearing that, it leads me to believe that it's a common problem with this motor. I could see it possibly being a bent rod or something, but makes me wonder why it'd only happen on the #1 cylinder and not the others.

mustangmike! · August 13th, 2010, 08:16 PM

I would think the miss fire part is because the lower psi, wrong mixture cause a premature detination or such not an expert so not saying thats right, doubt it would be a computing problem, sounds mechanical to me. the bent push rod idea sounds like its in the right direction, anywhere between cam and piston, so valves, springs, retainers, rods. like i said im no expert but that would be my guess from what little i know. im curious though sounds interesting to learn. i didnt take it but, sounds like your auto tech is more in depth than my hs was lol

Mr. Red Pony · August 13th, 2010, 08:57 PM

Im starting an auto tech class monday!! I get to sharpen my knowledge.

rfcsoulja · August 14th, 2010, 01:21 AM

Would a valve not seating correctly cause a missfire?

Mr. Red Pony · August 14th, 2010, 01:23 AM

Originally Posted by rfcsoulja

Would a valve not seating correctly cause a missfire?

When are you going to install my cam?

ESG-642T · August 14th, 2010, 02:11 AM

Originally Posted by rfcsoulja

Would a valve not seating correctly cause a missfire?

yes.

8A_Honda · August 17th, 2010, 10:52 PM

Okay folks. Sorry for the late reply but I was sick and skipped school yesterday. But anyway, the answer was kinda retarded cause we really didn't get all the info needed. Anyway, here's what happened.....

The headgasket blew and leaked coolant into the cylinder. It bent the rod but they didn't know it. They fixed the headgasket so there wasn't a leak in compression but it was lower because of the bent valve. I know the 3.8's are bad about headgaskets so that was the 1st thing I said. But he said the leakdown test showed no leakage. Anyway, that's the cause but was kind of a b.s. answer really cause he didn't tell the history at all. Had he mentioned that it HAD a blown gasket, I would've known the answer right away. But thought I'd report back on what it was.

Mr. Red Pony · August 17th, 2010, 11:58 PM

I win!! I was going to reply today and ask if the head blew, because I asked MY instructor and he said the essex engine have head gasket problems.

streetscraper1 · August 18th, 2010, 12:10 AM

so it had a bent valve and rod?

Mr. Red Pony · August 18th, 2010, 12:15 AM

Yup. I wonder how the valve bend though. But I bent my rod from a bad head gasket and had all those symptoms.

ESG-642T · August 18th, 2010, 12:29 AM

Oh look, exactly what I thought it was...

Mr. Red Pony · August 18th, 2010, 12:30 AM

Originally Posted by ESG-642T

Oh look, exactly what I thought it was...

WE were right sir.

August 13th, 2010, 02:59 PM	#21
Mr. Red Pony Resident badass 01 Built V6 (3.9) 13.91 @ 99.1 N/A Join Date: Jan 2010 Location: Lawton, Oklahomo Posts: 6,789 iTrader: 10 reviews	Bent connecting rod. I just remembered that when I bent mine is was misfiring a lot. And when they took it out they did a compress test and that cylinder was about 20 PSI less. (my piston was hitting the crank a BDC though) It wouldn't put as much pressure in the cylinder because the piston wasn't going up high enough. __________________ 271rwhp N/A V6 The Name is Danny. I'm a GM Technician. Suck it.

August 13th, 2010, 03:23 PM	#23
Mr. Red Pony Resident badass 01 Built V6 (3.9) 13.91 @ 99.1 N/A Join Date: Jan 2010 Location: Lawton, Oklahomo Posts: 6,789 iTrader: 10 reviews	I think it is the connecting rod. Is said engine 'real'? have you seen/heard it if so? __________________ 271rwhp N/A V6 The Name is Danny. I'm a GM Technician. Suck it.

August 13th, 2010, 08:16 PM	#25
mustangmike! I Post Entirely Way Too Much 2004,1994,1967 14.37 @ 96 Join Date: Aug 2008 Location: Texas Posts: 6,018 iTrader: 1 reviews	I would think the miss fire part is because the lower psi, wrong mixture cause a premature detination or such not an expert so not saying thats right, doubt it would be a computing problem, sounds mechanical to me. the bent push rod idea sounds like its in the right direction, anywhere between cam and piston, so valves, springs, retainers, rods. like i said im no expert but that would be my guess from what little i know. im curious though sounds interesting to learn. i didnt take it but, sounds like your auto tech is more in depth than my hs was lol __________________ 227whp N/A V6 Now w/ 8th Mile 8s ! How To Jmod Your Late Model 4R70W

August 13th, 2010, 08:57 PM	#26
Mr. Red Pony Resident badass 01 Built V6 (3.9) 13.91 @ 99.1 N/A Join Date: Jan 2010 Location: Lawton, Oklahomo Posts: 6,789 iTrader: 10 reviews	Im starting an auto tech class monday!! I get to sharpen my knowledge. __________________ 271rwhp N/A V6 The Name is Danny. I'm a GM Technician. Suck it.

August 14th, 2010, 01:21 AM	#27
rfcsoulja Hardcore Enthusiast 01 True Blue v6 to slow to matter Join Date: Mar 2009 Location: Oklahoma Posts: 1,141 iTrader: 0 reviews	Would a valve not seating correctly cause a missfire? __________________ My supercharged v6 http://www.youtube.com/watch?v=1lNkgKBw0bw

August 13th, 2010, 07:48 PM	#24
8A_Honda Regular Join Date: Jan 2007 Posts: 313 iTrader: 0 reviews	Well, I'm sure it has to be real. He told us that one of the keypoints to remember is that it's a 3.8 liter Ford motor. So after hearing that, it leads me to believe that it's a common problem with this motor. I could see it possibly being a bent rod or something, but makes me wonder why it'd only happen on the #1 cylinder and not the others.

August 17th, 2010, 10:52 PM	#30
8A_Honda Regular Join Date: Jan 2007 Posts: 313 iTrader: 0 reviews	Okay folks. Sorry for the late reply but I was sick and skipped school yesterday. But anyway, the answer was kinda retarded cause we really didn't get all the info needed. Anyway, here's what happened..... The headgasket blew and leaked coolant into the cylinder. It bent the rod but they didn't know it. They fixed the headgasket so there wasn't a leak in compression but it was lower because of the bent valve. I know the 3.8's are bad about headgaskets so that was the 1st thing I said. But he said the leakdown test showed no leakage. Anyway, that's the cause but was kind of a b.s. answer really cause he didn't tell the history at all. Had he mentioned that it HAD a blown gasket, I would've known the answer right away. But thought I'd report back on what it was.

August 17th, 2010, 11:58 PM	#31
Mr. Red Pony Resident badass 01 Built V6 (3.9) 13.91 @ 99.1 N/A Join Date: Jan 2010 Location: Lawton, Oklahomo Posts: 6,789 iTrader: 10 reviews	I win!! I was going to reply today and ask if the head blew, because I asked MY instructor and he said the essex engine have head gasket problems. __________________ 271rwhp N/A V6 The Name is Danny. I'm a GM Technician. Suck it.

August 18th, 2010, 12:10 AM	#32
streetscraper1 Regular 96 Boosted GT Join Date: Jun 2009 Location: Tyler Tx Posts: 447 iTrader: 0 reviews	so it had a bent valve and rod?

August 18th, 2010, 12:15 AM	#33
Mr. Red Pony Resident badass 01 Built V6 (3.9) 13.91 @ 99.1 N/A Join Date: Jan 2010 Location: Lawton, Oklahomo Posts: 6,789 iTrader: 10 reviews	Yup. I wonder how the valve bend though. But I bent my rod from a bad head gasket and had all those symptoms. __________________ 271rwhp N/A V6 The Name is Danny. I'm a GM Technician. Suck it.

August 18th, 2010, 12:29 AM	#34
ESG-642T [8MINUS2] 2002, Ford, v6 Join Date: Feb 2007 Location: TEXAS Posts: 12,319 iTrader: 0 reviews	Oh look, exactly what I thought it was... __________________ Hi, You can call me Kyle Random ESG fact: Had a prochamber on his v6 before it was popular. WTB: v6 BBK valve covers

Remove Advertisements Sponsored Links
Ford Mustang Forum Advertisement

Threads Similar to: Could it be the CPS?
Thread	Thread Starter	Forum	Replies	Last Post
cps	injected03stang	99-04	4	October 20th, 2008 03:27 PM
CPS??	CBSTANG	5.0 Mustangs	1	January 24th, 2007 09:37 PM

All times are GMT -4. The time now is 11:16 PM.
Contact Us - Modded Mustangs : Ford Mustang Forums - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.