Idling Issues
03-05-2011, 12:59 AM
#23
3rd Gear Member
Thread Starter
Join Date: May 2004
Location: Richmond, VA
Posts: 614
1994 Mustang GT, 306, TFS heads, cam, intake, BBK CAI, 24# MAF and injectors, headers, exhaust, 3.73s
Alright, so here's an update on the car. I took it to a different speed shop because I was pissed at the first one who couldn't fix the problem. After a ton of wire tracing, they determined that an injector (cylinder #7) was installed wrong & turned such that it caused the ground wire to short out. This backfed everything else and fried the CCM and ECM. Also, they had to replace the IAC and TPS because the IAC had a crack where a bolt was supposed to be and thus creating a small leak. They got the car back in good shape and tuned it. Everything is good. Right?
Not yet. The car idles perfectly, and under normal or hard acceleration it's great. I've only driven it about 20-25 miles from the shop, but I noticed when I pulled away that it sputtered a little bit. I've sort of attributed this to the engine being cold, cam being in the car, and basically a whole new computer system. However, when I was cruising in any gear and I eased off the throttle slightly, the car spit and sputtered. There was almost like a clanking noise as a result of the sputtering. Because the trip home was mostly on the highway, I noticed it more in 5th gear around 55-60 mph and 1700-1800 RPMs.
I plan to call the shop on Monday when they're open and let them know what's happening, but again I wanted to see if anyone had suggestions. I have limited ability to test things on my own, but I appreciate any advice. They did change the spark plugs along with replacing the computer modules. Is this behavior the new computer "learning"? Cats? O2s?
Alright, so here's an update on the car. I took it to a different speed shop because I was pissed at the first one who couldn't fix the problem. After a ton of wire tracing, they determined that an injector (cylinder #7) was installed wrong & turned such that it caused the ground wire to short out. This backfed everything else and fried the CCM and ECM. Also, they had to replace the IAC and TPS because the IAC had a crack where a bolt was supposed to be and thus creating a small leak. They got the car back in good shape and tuned it. Everything is good. Right?
Not yet. The car idles perfectly, and under normal or hard acceleration it's great. I've only driven it about 20-25 miles from the shop, but I noticed when I pulled away that it sputtered a little bit. I've sort of attributed this to the engine being cold, cam being in the car, and basically a whole new computer system. However, when I was cruising in any gear and I eased off the throttle slightly, the car spit and sputtered. There was almost like a clanking noise as a result of the sputtering. Because the trip home was mostly on the highway, I noticed it more in 5th gear around 55-60 mph and 1700-1800 RPMs.
I plan to call the shop on Monday when they're open and let them know what's happening, but again I wanted to see if anyone had suggestions. I have limited ability to test things on my own, but I appreciate any advice. They did change the spark plugs along with replacing the computer modules. Is this behavior the new computer "learning"? Cats? O2s?
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