hi everyone, i recently purchased a 2000 jimmy 4x4 sle. ive been a mechanic for 2 years and have tinkered my whole life. ive been having the usualy handfull of issues with my new ride and a few of them have left me clueless, i searched the internet and came upon this website, it seems very helpfull so ill give it a try, first and biggest problem. upon cold startup, or after running and sitting for about a half hour the truck seems to bog out when the gas pedal is pressed, almost like nothing happens. you can floor it during this time and its a no go. then after a few minutes of running all is well. the truck has no codes engine related. it has a new fuel pump and fuel lines. when i purchased the truck for an as-is lot this was a big mistake as i have already had to do the pump, brakes all around, both wheel bearings, various suspension parts, i had the drivers door esentialy fall off, i have yet to drop the front diff to put in axle seals, and i need to replace the air bag module. the list goes on, most of it being general maintnance. the plugs wires, cap and rotor look relitavly new. i know this is a huge post but id really aprechiate any help . thanks in advance.

 

my 2000 blazer had the same problem, did a tune up and it helped. i checked the old plugs and the gaps were all over the place (whoever did it before me didnt give the 2 seconds it takes to gap them) they ranged from a gap of .020 to .080 i i would check that and make sure your getting spark at all the plugs and all at start up.

 

My EVAP system, and secondary air system gave me lots of problems and my vehicle had similar issues. If you have any EVAP codes, try the gas cap. Like get a new one. For 5 dollars it cleared 3 of my codes. What codes are popping on your truck?

 

last time i checked i had absolutlry no engine related codes, just airbag, abs, and tranny, airbag and abs being the only current issues, airbag , i need to replace the module is the most commopn idea amoung my coworkers, and the abs i have an eratic right front sensor so i gotta replace it , probly just do the whole bearing scince it will need done anyway. my gas cap is kinda decrepit but i dont remember any evap codes. ill check again on monday though. cap and wires look newer, plugs i can tell their delcos but i havnt pulled any was they are a , well you know, to get to. i sprayed brake clean around the intake looking for any manifold leaks to no avail. so. this is were im at.

 

anybody at all?

 

Can you get ahold of a Mass Air Flow sensor-say from a pick and pull or swap one temporarily from a buds truck? Just a thought...jp

 

i could, what leads you to the mass airflow? it runs fine when warm . do you have the voltage ranges and or test procedure for it?

 

Welcome to the forum. Like any online forum, we have rules that we expect our members to abide by. Please have a read through them as they can differ from other forums you have been on in the past. Above all else, please be patient when asking for help.

Have you had your truck onto a scan tool that allows you to monitor the various sensors?

 

sorry if i broke any of them, ill read through. i hadnt heard from anyone in a while so i bumped up. no i havnt ben able to drive with one yet, maybe i can give it a shot while on my lunch tomorow. what should i watch for? leaning out? egr? etc.

 

I would pay attention to the O2 sensor output on B1S1 & B2S1 as well as TPS, MAP, MAF outputs. If you can record the data and then play it back, even better. Something is not properly reporting the conditions.