1992 inline six engine skips
Thread Starter
|
Freshman User
Joined: Jun 2005
Posts: 27
Likes: 0
1992 inline six engine skips
have 1992 4.9 6 cyl pick up with 5 spd and 99.000 miles. Always runs smooth at highway speeds and idles great but at low speeds it skips and misses.
A mechanic told me to disconnect the vacuum line from the egr valve and plug it and the miss would go away. I did this and it ran great but I got a check engine light.
I was told by the ford dealer to replace the vacuum control device that controls vacuum to the egr valve and if this did not solve the problem then replace the egr valve itself. I have replaced the Egr valve and the vacuum control with no change (still misses at low speeds) but with everything hooked up correctly the check engine light is out.
Plug wires, rotor, Dist. cap are new, last spark plugs were at 78,000 miles so they have 20,000 on them but the truck had the miss when they were new. The truck is bone stock and unmolested. Based on no change after putting in new egr valve I am sure I have a perfectly good used one in case some one needs one real cheap. Any ideas?
A mechanic told me to disconnect the vacuum line from the egr valve and plug it and the miss would go away. I did this and it ran great but I got a check engine light.
I was told by the ford dealer to replace the vacuum control device that controls vacuum to the egr valve and if this did not solve the problem then replace the egr valve itself. I have replaced the Egr valve and the vacuum control with no change (still misses at low speeds) but with everything hooked up correctly the check engine light is out.
Plug wires, rotor, Dist. cap are new, last spark plugs were at 78,000 miles so they have 20,000 on them but the truck had the miss when they were new. The truck is bone stock and unmolested. Based on no change after putting in new egr valve I am sure I have a perfectly good used one in case some one needs one real cheap. Any ideas?
Elder User
Joined: Dec 2003
Posts: 660
Likes: 3
From: Northern California
Originally Posted by dracip
have 1992 4.9 6 cyl pick up with 5 spd and 99.000 miles. Always runs smooth at highway speeds and idles great but at low speeds it skips and misses.
A mechanic told me to disconnect the vacuum line from the egr valve and plug it and the miss would go away. I did this and it ran great but I got a check engine light.
I was told by the ford dealer to replace the vacuum control device that controls vacuum to the egr valve and if this did not solve the problem then replace the egr valve itself. I have replaced the Egr valve and the vacuum control with no change (still misses at low speeds) but with everything hooked up correctly the check engine light is out.
Plug wires, rotor, Dist. cap are new, last spark plugs were at 78,000 miles so they have 20,000 on them but the truck had the miss when they were new. The truck is bone stock and unmolested. Based on no change after putting in new egr valve I am sure I have a perfectly good used one in case some one needs one real cheap. Any ideas?
A mechanic told me to disconnect the vacuum line from the egr valve and plug it and the miss would go away. I did this and it ran great but I got a check engine light.
I was told by the ford dealer to replace the vacuum control device that controls vacuum to the egr valve and if this did not solve the problem then replace the egr valve itself. I have replaced the Egr valve and the vacuum control with no change (still misses at low speeds) but with everything hooked up correctly the check engine light is out.
Plug wires, rotor, Dist. cap are new, last spark plugs were at 78,000 miles so they have 20,000 on them but the truck had the miss when they were new. The truck is bone stock and unmolested. Based on no change after putting in new egr valve I am sure I have a perfectly good used one in case some one needs one real cheap. Any ideas?
Most noted and common is the throttle body gasket being sucked in.
It's easy to replace...... go with a Felpro brand if you do replace it, It's thicker.
Other areas to check.....
Upper to lower plenum gasket
PCV valve
PCV hose (might need a couple of hose clamps on each end of it).
Lower intake to exhaust manifold gasket
Loose vacuum tree on the upper intake plenum
Allen wrench nut (for lack of a better term) on top of throttle body leaking
Charcoal cannister vacuum lines
Coffee cannister / hoses leaking
Leaking EGR valve....have you done a vacuum test on the valve to see if it holds vacuum ?
If all else fails, you can do the EGR restrictor plate "thing" or better yet, do what I did.
Go a hardware store and get a couple of 3/4" diameter fender washers, one with a 5/32" hole in it, and the other with a 7/32" hole in it.
Loosen the tube nut on the EGR valve and slide it back a little and insert the fender washer with the 7/32" hole in between the EGR valve and the flange for the EGR tube then snug it all back up.
This will allow EGR to flow (at a reduced rate) into the system and keep the CEL light off.
Test drive your truck a couple of days. If there's the slightest hint of a stumble or hesitation, do the above again and replace the washer with the 7/32" hole in it with the other washer that has the 5/32" hole in it.
In a sense.....it's an inline EGR Restrictor Plate !!!!
My total cost for this fix was 34 cents....and that was for 2 washers !!!!
Happy wrenching,
Bob
Last edited by Truckin Bob; Jun 27, 2005 at 05:52 PM.
