lagging at takeoff and squeaking
 

First time posting, long time reading. I have a '99 F250 7.3PSD w/115000 miles. I have Superchips 1705 at 90hp, 4in exhaust ,napa 6637 filter and 2 1/2 leveling kit. Mods came from ideas after reading your post. I have a problem and need some expert advise. Today, after 15mins of driving fine, I stopped at a light and when I went to pull away it would hardly move, with pedal down it slowly pulled through the light then caught and took off like it normally does. I have had this problem on 1 or 2 other occasions, but rarely. Today it did not cure itself. It started lagging on any acceleration at any speed. It did not do it ever time, but way to often. I also now hear a squeaking noise somewhere on the motor. I can't tell where it is coming from. I read the codes and pulled a P1119 and a P1211. I think I have seen these before, since the 1705 upgrade. I had to replace the CPS and the VSS last year. New fuel filter last month. Any ideas or comment are welcomed. Thanks

Sounds like the EBPV. (Exhaust Back Pressure Valve) I had the same problem so I just eliminated it. If you just unplug it you will get a code that comes up so I ordered a EBPV Eliminator from Black Cloud Diesel. If it is cold more often then not where you are from you might not want to disconnect it. Warms the engine up faster! I don't know what the squeeking is, sorry!http://www.blackclouddiesel.com/Ford/ebveliminator.jpg

Welcome to the ranks of the posting. Glad to have you aboard.

The P1211 code is the "normal" ICP code caused by performance tuners, so it probably is unrelated.

The P1119 (manifold air temperature sensor high input) is a new one for me. The PCM does adjust fuel and timing based on the MAT sensor input, so if that sensor has failed it may cause the symptoms you describe.

Squeaking noise??? Is it only while moving? Like maybe a binding universal joint on the driveshaft?

Thanks for the response. The squeaking is in or on the motor. I hear it more after the truck warms up. Don't matter in or out of gear. It responds to engine RPMS. Sounds sorta like a belt or bearing. I can't find a reason. It started the same time as the other problems. I did find a wire harness with two wires unplugged from some sort of sensor on top of the engine. I was on the front of the base of the intercooler. I have not had a chance to find out what it is for. I did not notice the lagging after plugging it back. The throttle response seems to be back to normal. The P1119 code has been showing up since I did the air filter mod. Hope to get to drive more tomorrow and see if the lagging shows up again. Still open to any suggestions. Oh yea, I looked for the EBPV, where is it? I did not have much time to look, but could not see it. Thanks,

Here is a link with instructions. http://www.blackclouddiesel.com/Tech...2005-08-17.pdf.

Dont mean to change the subject, but the squeaking noise? I recently have been hearing one, and it sounds like its underneath the vehicle but only in 1st and 2nd gear, soon as I shift into 3rd it doesnt squeak. Kkiwwkordead, you said possible a u joint? I hope not, I just put in a new universal joint! Its a high pitched squealing with the presence behind it that its rotating or moving. Ne ideas?

What did you do with the temp sensor that was in the stock box? Wonder if it is tied into the "The P1119 (manifold air temperature sensor high input) is a new one for me. The PCM does adjust fuel and timing based on the MAT sensor input, so if that sensor has failed it may cause the symptoms you describe." I have never heard of this either, and could not find anything remotely similar in the schmatic besides the AIT (air intake Temp). Anyone know anything more about the MAT sensor?

The air temp sensor that was in the original filter box is tied to some wires on the fuse box. I think the 2 wire harness I found unplugged was the MAT sensor. It is located on the front of the crossover where the intercooler ducts meet at the TC. I drove some last night and then on the way back from work and did not notice any lagging or pausing at all, in fact it seemed very strong and responsive. I haven't had a chance to clear the codes and recheck yet. I will keep checking back for more advice and help. Thanks again.

The MAT sensor is the one on the front side of the five way intake manifold. Right smack in the middle of the engine. It sounds like that is the one you plugged back in.

Yep, that the one that was unplugged. I hope that solves the lagging problems. What problems will it being unplugged or not working cause? Still can't find the squeaking, but still looking. Thanks for your patience with me, I bought the truck new in '99 but still don't know the names or purpose of alot of the parts. I had alway ran gas trucks before and worse yet Chev. I do most of my work myself and not afraid to tackle the job. Most of what I have learned is from reading these post. Your ideas on mods have cost me some but worth every penny. The help I found on repairs and tips saved me more that the mods have cost. thanks guys http://campaigns.ford-trucks.net/for...cons/icon7.gifhttp://campaigns.ford-trucks.net/for...ons/icon14.gif

Now I know where it is, thanks Cookie & zx250