no power under load

Slaver · #1 02-14-2005, 11:50 PM

I own a 1996 Jimmy, V6 vortec 4.3L VIN Code W. I have read through all the threads and haven't exactly seen anything like this. Recently I drove through a large puddle which made my wipers unable to turn off and set off check engine light. Things dried out wipers worked, light would not go off. Got codes checked came up PO446 - EVAP system Canister Vent Blocked. Checked gas cap, fuel lines and vacuum lines in system and no leaks. Reset computer and the light went out and has not come back on two weeks later. Now there is a lack of power, a clicking noise from the dash, and some indecision with the jimmy when going up hills or under load. Checked the tranny, it was very low so I filled it up. Also put new air filter and fuel filter in as first steps in hopefully diagnosing the problem. Still having same problems. If anyone could please get me going in the right direction it would be very much appreciated. Thank you.

BlazerLT · #2 02-15-2005, 12:52 AM

Check your evap canister for water.

Slaver · #3 02-15-2005, 09:42 PM

Jimmy seems to be getting rougher not so much at Idle but when driving. I pulled the canister out today. No water, tubes were not plugged, everything seems OK. I did see a lot mentioned about the PCV so I looked into it. I pulled the hose off and there is no valve in it. I went and bought one but it doesn't seem to fit anywhere. I'm looking at the tube that comes off the air intake and goes into the Valve cover on the passenger side. Any ideas or direction would be great. Thank you.

BlazerLT · #4 02-15-2005, 09:52 PM

Quote:

Originally Posted by Slaver

Jimmy seems to be getting rougher not so much at Idle but when driving. I pulled the canister out today. No water, tubes were not plugged, everything seems OK. I did see a lot mentioned about the PCV so I looked into it. I pulled the hose off and there is no valve in it. I went and bought one but it doesn't seem to fit anywhere. I'm looking at the tube that comes off the air intake and goes into the Valve cover on the passenger side. Any ideas or direction would be great. Thank you.

The PCV valve for your year is in the driver's side valve cover.

Maybe you should look into doing a full tuneup.

Slaver · #5 02-17-2005, 05:34 PM

BlazerLT thank you for letting me know where the pcv was, found it and replaced it. I also now have put in new air filter, fuel filter, Oil and filter, plugs, cap, rotor, and wires. Unfortunately no change in jimmy function, no power, surging, rough shifting, and I only get about 375km to a tank. Any other suggestions. Thank you.

BlazerLT · #6 02-17-2005, 10:29 PM

Quote:

Originally Posted by Slaver

BlazerLT thank you for letting me know where the pcv was, found it and replaced it. I also now have put in new air filter, fuel filter, Oil and filter, plugs, cap, rotor, and wires. Unfortunately no change in jimmy function, no power, surging, rough shifting, and I only get about 375km to a tank. Any other suggestions. Thank you.

What kind of plugs did you use?

Clean you MAF as well and take a gentle toothbrush and TB cleaner to it and get the grunge of of the two sensor wires. Then rinse with cleaner.

How many kms on your truck?

smonaldo · #7 02-18-2005, 01:49 PM

Surging? What kind of surging? In the rpms. It almost sounds like you are describing something I had a problem with, where the vehicle was sluggish, felt like it wasn't shifting right, slipping, and would constantly drop rpms when I got up to 3k. Mine turned out to be a Transfer control module shorted out by a damaged wire harness, and the computer/transmission believed that the vehicle was in 4wd low when it was not, thus tried to limit rpms and such. I even lost the drop down capabilty when I tried to pass. Gas mileage dropped to about 8-10 mpg. I took it to AAmco, they had it for a whole day and said the trannny was fine. The dealer diagonosed and repaired the problem. Can you relate to any of the above symptoms?

Slaver · #8 02-23-2005, 07:00 PM

I cleaned out the MAF sensor and the EGR, no difference. My jimmy has 145000KM on it. The fuel pressure is getting checked later today. I'm starting to lean towards a new CPI ,or which ever injection system is on this motor, there is a really strong gas odour through the throttle body. As for Smonaldos' reply I'll check out the Transfer Control Module, thanks.

Slaver · #9 02-24-2005, 01:00 AM

Well I had the Jimmy checked out today. The fuel pressure is good, the vacuum readings are good, everthing checked out. Then we pulled out the O2 sensor infront of the Catalytic Converter and the damn thing ran great, by pulling the O2 sensor it gave the exhaust some where to go. So it was a plugged catalytic converter all along. Now I just have to find one for a decent price, I guess they go for about $500.00. Anyone else that has these symptoms try it out, this simple step will save you time and money.

Thanks to BlazerLT for all your help, it was appreciated.

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