88 mustang gt idle problem

[fiveohfox]

i have an 88 mustang 5.0 ho 5 speed, speed density t top... well i put on an off road h pipe over the winter replaced the starter and cap and rotor spark plugs and spark plug wires oil change and now when i start my car it idles fine for 10 mins and then starts surging and then sometimes when i down shift it pops and crakes and then backfires and when i go to really jump on it there is a lack of power it dosent slam u in ur seat it has a hesitation.. idk what to do someone help me..... i was told to run the check engine codes but idk what that is or how to do it!!!

 

[bagged89-5.0lx]

Sounds like you may have a timing issue... Or a couple plug wires crossed...did you actually remove the distributor?

 

[bagged89-5.0lx]

The port u plug the code reader into is under the hood on the driver side,in the corner between the fende and brake booster. And any good parts store should be able 2 read the codes for u.good luck...

 

[fiveohfox]

i tried changing the timing and it made it worse so i set it back to where it was witch is stock..and no i just changed the cap and rotor... and the plug wires are perfect i have checked everything!! any other computer problem it could be or anything i am not thinking of..... it kinda feels like theres to much air moving throw the off road h pipe... like there might not be enough back pressure???

 

[HISSIN50]

As suggested you need to pull codes.

The Useful Tech sticky has info about doing it if you don't want to look in your repair manual.

 

[Dachipsta]

Somewhere around here there is a link to a page about checking and cleaning up the connections on the "Salt & Pepper" connectors. These are the two wire harnesses in the back of the engine compartment that fasten to the back side of the stock upper intake manifold. If your manifold has been replaced and upgraded then they may just be laying around the back of the engine somewhere. Anyways, if the connections on these two harnesses get loose or dirty, they can cause quirky little problems with how the engine runs and idle issues is one of them. Someone on here may chime in with the link I'm talking about or you can do a search for "Salt and Pepper Conectors"........l8r

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

The checklist has the procedure on how to dump the computer codes and lots of help on finding and fixing the idle surge problems.