How can a person test for a bad cop/plug when there are no codes? I called a shop to get a tune up estimate and he said how with these trucks it could be a bad cop and that he could test for it. I have a reader that attaches to my computer which gives live time info etc. So do I already have the tools, if so what do I look for?

 

If you can read pending codes you may be able to find the culprit. I had a really bad stumble that didn't trigger the CEL, but the information was in the pending codes. I don't have a reader, the dealer pulled the info.

 

I had the same problem and I had to drive it hard to get it to finally throw the code.

 

I am having a similar or I should say exactly the same problem but it has never thrown a code. Put new plugs in in july. This problem is driving me crazy as well. Mine usually happens in between 1200 and 1500 rpms but if I step on it it takes off like a rocket. Are there 2 fuel pumps , A low pressure and a high pressure or am I heading in the wrong direction all together? I have a '99 5.4 ltr. and am going to change the plugs and try to test each cop while it's off. The last time this happened (in July) changing the plugs fixed it so it's worth another shot. I also replaced one cop that was underneath a leaky heater hose but didn't solve the problem. I have also thought of using the one new cop and going one by one till I find the bad one. It has never thrown a code or died and only does it at low rpms under a load.
Sorry for the hijack


Bernie

 

Problem fixed!! Went to Lee Auto and picked 1 cop and started with the hardest one(#4 under the heater hoses). Changed it, no difference. Did the same to the #3, #2 then the #1 (the easiest to change)and that was the one. Didn't have try any others the truck is running smooth as silk. It took a little time and patience to track it down but was worth the effort and was only $42.00 out the door and a little time.

Bernie

 

Glad it worked out that way. The day I was to take mine, it started making a clicking sound on the upper right toward the front. Took it to the shop and the say timing chain

 

Bernie,
You have a lot more patience then me, starting at # 4. Good thing you didn't need to go further on the driver's bank. Just changed plugs this weekend again and it reminded me that also having to remove the fuel rail to access #'s 7 and 8 is no fun either.
Glad to hear it's fixed.

 

quote]Glad to hear it's fixed. [/quote]
Thanks, I know what you mean. I changed the plugs last July, what a pain. But I muscled through it.

Bernie

 

Ouch!! Sorry to hear about that. I've got 142k on mine and that's probably not too far off in the future for me as well. Hope it works out ok.

Bernie
12amracerGlad it worked out that way. The day I was to take mine, it started making a clicking sound on the upper right toward the front. Took it to the shop and the say timing chain