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My car runs like crap

  • Thread starter Thread starter htrdmstng
  • Start date Start date Jun 14, 2004

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 14, 2004
#1
  • Jun 14, 2004
  • #1
Okay, my '91 LX is still running like crap. I have searched the threads here and have tryed everything sugggested in them but no luck. All of my mods had been on the car for a year before the problem started.

For the problem. It started about a year ago when it was becoming difficult to start when cold (cranked a long time before firing), but started fine when hot. It progressivly got worse until it is where it is at now. It will fire right up, but it sputters and stalls on cold start. When it stays running it idles kinda rough, it also backfires out the intake and bucks a little when driving until it is warmed up. When it is warmed up it has no power below 3000 RPM.

Now for what has been done to fix it so far. I pulled codes And have done repairs accordingly. I can't remember the codes but as for the repairs I have replaced the evp, ect, act, tps, idle control assembly, spark plugs, cap, rotor, wires, TFI module, coil, timing chain and added a MSD 6A module. My fuel pressure is at 45 psi, timming is currantly at 20 degrees but has been retarded all the way back to 10, but runs better with more advance, and compression is at 110 psi but I don't trust my gauge I want to check it again with a different gauge.

Sorry to be so long winded but wanted you to have all the info. Any help would be great, Thanks
 

79'293stang

Active Member
Jan 5, 2003
505
11
29
Cedar Rapids, Iowa
Jun 14, 2004
#2
  • Jun 14, 2004
  • #2
i dunno but 110 seems a lil low to me for compression my engine that came with the car when i bought my stang a couple years ago came out of a worn out truck and still pushed between 130 and 150 but im not to informed on that kinda stuff so i may be wrong
 
N

Nottoofast50

Founding Member
Dec 9, 2000
386
0
0
Cali
Jun 14, 2004
#3
  • Jun 14, 2004
  • #3
110 does seem kind of low but i think what matters is that all cylinders are within 5-10% of each other..
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 14, 2004
#4
  • Jun 14, 2004
  • #4
It is at 110 on all cylinders, but my gauge has been dropped so many times I don't trust it. I want to check it again with another gauge.
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 14, 2004
#5
  • Jun 14, 2004
  • #5
Okay, I just rechecked my compression and it was at 125-130 across the board. I also check my friends and his was the same.
 
1

14secSleeper

Founding Member
Aug 30, 2002
59
0
6
Jun 14, 2004
#6
  • Jun 14, 2004
  • #6
have you checked your mass air???? my car would run like that before i replaced mine. It would run like cccraaaap when i first started and i would hear a popping coming out from the intake. it would sound only when cold then when she would warm up the car would run better but would lack power across the board. I changed that and it made a world of difference. C+L junk....try to borrow a friends or something to see if that could be the problem????
 
S

somersdp

New Member
Nov 16, 2003
191
1
0
WPB,Florida
Jun 14, 2004
#7
  • Jun 14, 2004
  • #7
$100 says its the 02 Sensors........
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 14, 2004
#8
  • Jun 14, 2004
  • #8
Thanks guys, I replaced the O2 sensors and mass air about a two years ago, but then that doesn't mean they are any good. I will check them to be sure.

Thanks again
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 15, 2004
#9
  • Jun 15, 2004
  • #9
ttt
 
H

Horsepower67

New Member
Feb 1, 2004
62
0
0
Jun 15, 2004
#10
  • Jun 15, 2004
  • #10
Check the TPS voltage as well. Should be .95 to .99.
Check out the procedure here:
http://www.50tech.com/articles/display_article.php?catid=9&id=10
I'm betting it's in the ignition system somewhere.
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 15, 2004
#11
  • Jun 15, 2004
  • #11
TPS is at .98. I have good spark and the ignition has been completly overhauled. As stated above I replaced the plugs, cap, rotor, wires and TFI module, not stated above I put in a MSD coil and 6A module all after the problem started. The distributer was replced about 20k miles ago because the old one seized.

Thanks everyone for the ideas
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 15, 2004
#12
  • Jun 15, 2004
  • #12
MAF it is. Swaped it out with my friends and my car ran great for the first time in a year. Thanks guys.
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 18, 2004
#13
  • Jun 18, 2004
  • #13
Well that didn't last long. I'm right back to where I started. Any more ideas? My friend is letting my barrow his 91 to swap parts back and forth to help out. Thanks again.
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 18, 2004
#14
  • Jun 18, 2004
  • #14
ttt
 
H

Hydrocarbon

New Member
Nov 18, 2003
160
0
0
Medford Oregon
Jun 18, 2004
#15
  • Jun 18, 2004
  • #15
Check timing advance to make sure its working. If the car runs better with 20 degrees of timing the SPOUT circuit maybe open.

You can try forcing the computer into "failure mode" to pinpoint problems, by unplugging the MAF, o2s, ACT, or ECT. I used this method to find out my o2s weren't being heated.

Double check all computer ground wires and clean and pack the 10-pin connectors with de-electric grease.
 

bluevenom867

I will have images of molesting stuffed animals in
Dec 15, 2003
1,704
1
0
St.Petersburg,FL
Jun 19, 2004
#16
  • Jun 19, 2004
  • #16
Bad strater solinode? Coulden't think of any thig else at the moment.
 

bluevenom867

I will have images of molesting stuffed animals in
Dec 15, 2003
1,704
1
0
St.Petersburg,FL
Jun 19, 2004
#17
  • Jun 19, 2004
  • #17
man,I'm tired,good night 5.0 board.
 
M

mstangracer

Founding Member
Oct 30, 2000
196
0
0
Houston TX
Jun 19, 2004
#18
  • Jun 19, 2004
  • #18
why so high puel pressure ? try droping it back to 40 or even 38 psi

good luck
phil
 

htrdmstng

New Member
Oct 16, 2002
21
0
0
SLC, UT
Jun 19, 2004
#19
  • Jun 19, 2004
  • #19
hydrocarbon, the timing does advance and retard as I install and remove the spout. It also advances when I snap the throttle with the spout in.

mstangracer, set the fuel pressure back to 38 psi with no change.

I didn't think to mention this before, but when all this started I went from 26 mpg highway to about 10 mpg highway.
 
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