Trouble code 43,44 help

[rivermtnman]

Hey All,

I need some help trying to troubleshoot some problems I've got on my '88.

It's giving 3 codes:
32-EGR-had this since I bought blazer 3 years ago, never tried to fix.

These I've got in past 2 weeks:
43-Electronic Spark Control-manual says to check A-B connector terminal B7 for atleast 6 volts, checked, about 9 volts. Says to replace ESC sensor and or module.
44-Lean exhaust-manual says to check fuel pressure, oxygen sensor wire, vacuum leaks. Says to replace oxygen sensor.

OK now what the blazer's doing. Highway speeds, runs fine. Getting there it sucks. If I go up a hill, my ridin mower could out run it, or if I kick down on it, it does nothing power wise. To get up to speed less throttle the better.

2 months ago put new plugs, wires, rotor button, cap. About a month ago installed a Airaid TBI spacer. It seemed to help power also. But as I said earlier in past 2 weeks it is running like crap. It seems more of an erratic miss(sputtering), because I can let off gas pedal to get sputtering to go away, than a firing miss.

My question is with the last 2 codes, one says possibly fuel, the other says electrical. Has anybody seen this, and does anybody no where I should start, fuel or electrical?

I also changed out fuel filter/pump about 2 years ago. Blazer has 159k and 700R tranny.

Could fuel filter be clogged? What about the ESC not allowing the timimg to advance? Either might cause this problem?

I checked timing its on 0BTDC, connect wire back on firewall and it goes to 12BTDC. We put it in gear, held brakes, and gave it gas (tried to simulate a load on it), and timing started coming back toward TDC, made it to about 6BTDC. Is this the right direction?

Anyway, I believe I've explained all I've done, but I dont know what to try next. Hate to start buying things, just hoping to get lucky.

 

[Thunder]

1st thing to do is change the fuel filter.
Should change your fuel filter yearly. Sounds like the filter is clogged.
Change filter and see if the 44 goes away. Also check for vacume leaks.

The bad/stuck open egr can also cause a 44 by leaning out the fuel mixture..Check for proper EGR operation and also the Egr solonoid.
Usually your truck will idle like crap if the EGR is stuck open
43 is usually the knock sensor. But it could be that your engine is running so lean because of a bad filter or EGR that it sets off the code 43 because it is pinging. When the knock sensor detects pre detnotation /pinging. it reduces timing advance till it goes away. This will cause a power loss. if it doesn.t go away it sets the 43

 

[rivermtnman]

BINGO!!!

Thanks a ton, Thunder! I was hesitant on the fuel filter because last time I changed it, the braided hose on the TBI side about 2' long had a hole in it at the filter. After several hours and a couple of hose clamps I finally got it to quit leaking. This time I went to Napa and they sold me a 1' piece of fuel injection hose, and I cut the braided line out. No leaks now. Anyway pulled fuel filter off, had this mud, rust mixture from tank side. Runs great now.

Awesome advice, thanks again. /forums/images/graemlins/thumb.gif

 

[Thunder]

Glad you got it running good /forums/images/graemlins/thumb.gif