HELP! - Intermitant Tachometer and Rough Idle
#1
HELP! - Intermittent Tachometer and Rough Idle
Truck started acting up a few days ago. Tachometer goes off for a second and engine runs rough, then tach comes back and engine smooths out. This triggers the Check Engine light. After a few OFF-RUN cycles on the key light goes out but comes back when tach falls off again.
I spent an hour or so on Saturday cleaning connections and grounds and test drove without problem but today while running errands it happened again but this time worse; tach stayed off for about a minute or so. While tach is off engine surges and sputters.
I've read a previous thread here on this but there isn't any conclusion on it so I figured I'd ask this again.
Please help!
Thanks
I spent an hour or so on Saturday cleaning connections and grounds and test drove without problem but today while running errands it happened again but this time worse; tach stayed off for about a minute or so. While tach is off engine surges and sputters.
I've read a previous thread here on this but there isn't any conclusion on it so I figured I'd ask this again.
Please help!
Thanks
Last edited by Toomany Tools; 04-07-2008 at 05:03 PM. Reason: spelling error
#2
Registered User
Join Date: Jan 2005
Location: East Bound and Down Loaded Up and Truckin'
Posts: 233
Likes: 0
Received 0 Likes
on
0 Posts
I would say LP, IP, Apps, or ECM. The only reason why I said all of those is because I had the same kind of problem and those are all of the things that I have replaced in the last 4 months. I would look at your cam shaft position sensor also.
Are you getting any codes?
Are you getting any codes?
#3
Just got back from AutoZone where they pulled the codes for me: P0336 Crankshaft Position Sensor; P1680 IPM crank sensor does not agree with ECM crank signal.
If it's the position sensor I don't understand why the issue is intermittent?
If it's the position sensor I don't understand why the issue is intermittent?
#4
Registered User
Join Date: Sep 2004
Location: Albany MO
Posts: 140
Likes: 0
Received 0 Likes
on
0 Posts
on my 1998.5 it came and went like yours. Pulled the starter and changed the crank sensor and no more problems. Do a starter contact replacment while you have the starter pulled. I didn't and about 30 days later had to pull the starter and do the rebuild anyway.
TallTom
TallTom
#7
Changed out crankshaft position sensor this morning and seems to have fixed it.
Found BIG difference in price on the part: AutoZone - $62; Checker - $55, Dealer - $112, and NAPA $45. I'm glad I shopped around by phone before I bought.
Found BIG difference in price on the part: AutoZone - $62; Checker - $55, Dealer - $112, and NAPA $45. I'm glad I shopped around by phone before I bought.
Trending Topics
#8
Registered User
Same Problem??
I've had the same problem with my Tach, but ONLY when it's raining and the roads are wet. When the roads are DRY, I never have a problem.
Where should I check for loose connections? or Where should I spray some silicone to water proof my connections?
Thanks
-Tim
Where should I check for loose connections? or Where should I spray some silicone to water proof my connections?
Thanks
-Tim
#9
Registered User
Join Date: Mar 2008
Location: New Bern NC
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
Believe it or not-I had same problem with 99 QC 2500 frequently an wound up being fuel cap. Apparently was not venting ,creating vacuum and starving engine of fuel.When tach bottomed out I had to open cap an truck would be fine. Such a vacuum- it would cave in fuel tank until relieved.
#10
Registered User
Join Date: Jul 2008
Location: Seymour, IN
Posts: 165
Likes: 0
Received 0 Likes
on
0 Posts
check your connection on the back of your transfer case that should be on the tailhousing. That is where i would start.
Thread
Thread Starter
Forum
Replies
Last Post