hi, ok I just got home from work and when I pulled into my driveway my truck started surging at idle ............rev it up and it smooths out ???..........back to idle and it surges<br><br>so I'm thinking maybe it's the comp box, so while engine is running I unplug it ............still surges.........I plug it back in and the check engine light comes on .......I should have turned the truck off first to plug it back in right<br><br><br>soo, how do I reset the check engine light first, and does anybody have any ideas on why it might be surging .........up untill tonight it had a silky smooth idle<br><br><br>it's a 99 quad cab 4x4, 5sp .......with a 24valve .......has rv275 injectors and an edge comp on it .......<br><br>help please, it would be much appreciated .......<br><br>

 

I have a couple of questions for you to help diagnose the problem.<br>1: When was you last fuel filter change or drain?<br>2: How long have the new injectors been in?<br>3: What is your tach reading at idle?<br>4: Does it act up from start up, or after the engine warms up?<br>Answer these questions, and we will see if we can help.

 

filter was last changed in october .....but the fuel pressure gauge still reads 15 idle, 12 cruise &amp; 10 WOT<br><br>injectors were installed in january<br><br>tach reads around 800 jumps up too 900 on surge<br><br>was fine when I left work with the truck cold.. .....it was 86 degrees out side, 30 mile trip, temp gauge on the truck read just slightly above 195 degrees<br><br>when I got home and the truck was hot is when it acted up .....started it this morning before I left for work no surge but there was still a check engine light .......<br><br><br>I didn't drive it to work so I don't know if it still acts up after it's warm<br><br>thanks

 

you might need to reset your accelarator position sensor or clean the plug mine was doing that until i cleaned it.

 

I am not sure how to reset the computer, maybe someone else can inform us. After you reset the computer, run the self check and pull the codes. Below is the instructions on how to do both.

If you hold the trip/odometer button in while turning the key to the 'on' position, the computer will go into a self check mode.The gauges will all max out, one by one in this mode. When it is done in this mode, turn the key off. Then, turn the key on-off 3 times, ending in the on positon to retreive the codes. Below is a link that takes you right to the OBDII list of codes.

http://www.obdii.com/codes.html

 

Sounds like the crankshaft position sensor (CPS) might be going bad. That will cause the symptoms you are having.

 

just wanted to say thanks for the replies, got my problem fixed<br><br>turned out to be a hole worn in the main line from the fuel tank and the lift pump was sucking in air and causing the problems ........new fuel line fixed the problem <br><br><br>

 

Thanks for letting us know the problem.