Engine 1990 5.0 Engine "stutter" miss

KaptKane

New Member
Jun 19, 2018
25
2
3
76
SW FL
IMG_5257.jpg
Newb here. My 90, 5.0 5 speed has developed an occasional "stuttering" type of engine miss at low RPM and lite throttle. Running it up through the gears at full throttle (thru 3rd anyway) it seems to run smooth and strong like it always has. I only seem to get that "stuttering" miss when like cruising on a city street and I shift up to 5th and the RPMs drop around 1300/1400 and lite throttle just to keep up with traffic. Its intermittent and I can't "make" it happen.
Supposedly (as told to me by the guy I bought it from) it has a 303 cam and Explorer upper/lower intake and this "Intense Tuning" module. (please see attached pic)
All my years of fooling with cars told me it was a plug wire going bad. So, I put new plugs, wires, distributor cap and rotor. The miss is still there!
Incidentally, when I changed the plugs, all were burning that nice light tan color except #4. It was definitely darker (almost black) like it was burning more rich than the other cylinders.
Ideas?
Thanks in advance.
 
  • Sponsors(?)


General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
13,844
4,356
193
polk county florida
I would start with a compression test to see if you have a problem in that one cylinder.
there is a thread here that can help save you from chasing your tail and wasting money.
Start at the top and do it step by step. Don't skip around, the next step depends on the result from the previous one.
Jrichker put it together ant it works.
 

Real time recon

Mustang Master
Aug 21, 2016
469
203
83
...
I had a problem like you mention.I took the MAF sensor off (cleaned it with the "proper" spray cleaner). IT looked "clean" (before I cleaned it) ,but I figured W.T.H and did it anyhow. after it was cleaned, I noticed a Hugh difference in how clean it was...........Reinstalled MAF sensor 1/2 hr later after it was completely dry
002.JPG
..........and problem solved.!:) Purrs like a kitted :)
 

KaptKane

New Member
Jun 19, 2018
25
2
3
76
SW FL
Awesome! So...what's the "right" cleaner? Carb cleaner? Electrical cleaner? I sure hope my reacts the same as yours did!
Thanks.
 

KaptKane

New Member
Jun 19, 2018
25
2
3
76
SW FL
So...I removed the MAF and sprayed it good. Replaced it after I was sure it dried good. Drove it 60+ miles this morning and (knock on wood) it hasn't acted up!
Thanks for the tip. If anything changes, I'll be sure to post because I'll be looking for help!
20190629_093902.jpg
 
  • Like
Reactions: Real time recon

Real time recon

Mustang Master
Aug 21, 2016
469
203
83
...
So...I removed the MAF and sprayed it good. Replaced it after I was sure it dried good. Drove it 60+ miles this morning and (knock on wood) it hasn't acted up!
Thanks for the tip. If anything changes, I'll be sure to post because I'll be looking for help!
20190629_093902.jpg
Glad to hear that !:) I'm thinking these air filters (come from the factory) coated with a very thin coat of oil (to help keep out dirt/dust) and THAT oil over time gets sucked into the MAF sensor.
 

Real time recon

Mustang Master
Aug 21, 2016
469
203
83
...
Also sometime take a look at the PVC Valve and filter/screen that's just under the PVC
004.JPG
valve.Here's pix. of the old and new one(old on the right,new one on left) .
See how dirty the old screen is.........
 

Blown88GT

Founding Member
Nov 13, 1999
1,662
304
124
Palm Beach Gardens, FL
IMG_5257.jpg
Newb here. My 90, 5.0 5 speed has developed an occasional "stuttering" type of engine miss at low RPM and lite throttle. Running it up through the gears at full throttle (thru 3rd anyway) it seems to run smooth and strong like it always has. I only seem to get that "stuttering" miss when like cruising on a city street and I shift up to 5th and the RPMs drop around 1300/1400 and lite throttle just to keep up with traffic. Its intermittent and I can't "make" it happen.
Supposedly (as told to me by the guy I bought it from) it has a 303 cam and Explorer upper/lower intake and this "Intense Tuning" module. (please see attached pic)
All my years of fooling with cars told me it was a plug wire going bad. So, I put new plugs, wires, distributor cap and rotor. The miss is still there!
Incidentally, when I changed the plugs, all were burning that nice light tan color except #4. It was definitely darker (almost black) like it was burning more rich than the other cylinders.
Ideas?
Thanks in advance.
Bad News.
 
  • Useful
Reactions: General karthief

KaptKane

New Member
Jun 19, 2018
25
2
3
76
SW FL
Thanks for the update. I was being "cheap" and figured I could pick up another 10hp for $20. I guess I got what I paid for!
If you look at my updated pic in the thread (that shows the can of CRC MAF Cleaner sitting atop the MAF housing) you'll notice that the "Intense Tuning" module is gone. I removed it as part of trying to get me engine running correctly again.
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,120
2,647
224
73
Dublin GA
You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
27,192
9,620
224
Box behind Walmart
www.stangnet.com
You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
You mean the one from post 2? :p