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Installed 1" body lift....Now idles bad.

wheels87k5

wheels87k5

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Installed new body mounts and 1" lift......after truck warms up, it wants to idle too low and seems like it wants to die.

It ran fine before the install.....and no codes are popping up. I checked all ground connections and wiring. And also checked fuel lines. I haven't found anything smashed or unplugged.

Is this a coincidence and maybe a sensor has failed or did I do something that I haven't found yet.

It's running at 13-14 lbs of fuel pressure so that hasn't changed. I get good spray at the injectors.

And it suprises me that it's not throwing codes.

Where to start? I'll run winaldl and see what it says.....maybe it'll throw a flag and I can start there.

And your suggestions?
 
Maybe pinched a wire running back to fuel tank? I think a wire loom runs right by those body mounts. Maybe causing an intermittent pump issue?
 
wheels87k5 said:
Installed new body mounts and 1" lift......after truck warms up, it wants to idle too low and seems like it wants to die.

It ran fine before the install.....and no codes are popping up. I checked all ground connections and wiring. And also checked fuel lines. I haven't found anything smashed or unplugged.

Is this a coincidence and maybe a sensor has failed or did I do something that I haven't found yet.

It's running at 13-14 lbs of fuel pressure so that hasn't changed. I get good spray at the injectors.

And it suprises me that it's not throwing codes.

Where to start? I'll run winaldl and see what it says.....maybe it'll throw a flag and I can start there.

And your suggestions?
Click to expand...

My buddy has an '89 that was doing similar, we used the shotgun approach seeing as I had a complete known good running TBI 350 sitting on the floor in my carport. We methodically replaced every single sensor with no change. Truck had no codes either. Finally pulled the cap on the distributor and it appeared to be self destructing. Full of red dust...it was wrecked. We swapped in the distributor from my spare TBI 350 and problem solved.

Maybe the firewall hit the cap on your distributor when you were doing the body lift?
 
I checked timing thinking that maybe the body moved the dist. out of it's original setting. With the wire (black and tan) unplugged, the timing was at 8 degrees. Reached for the dist cap and was able to move it but it took both hands to get it to turn....I set timing to 0 and plugged wire back in.

Seems like it runs at idle ok now but has a slow surge to it....I sprayed carb cleaner all the way around the gaskets and vacuum lines....didn't change anything so no leaks found.

I do remember that when I changed out this gas tank 2 weeks ago, I had to readjust the fuel pump in its mounted position because it would bottom out and I couldn't close the retainer ring. When I had to lower and raise the tank from beneath, I wonder if it has done something to the pickup tube on the pump. I'll pull the pump and sending unit out and look to make sure it didn't get damaged.

I'll also check the dist cap and make sure it didn't get damaged.

Other than that I don't know where the slow surge is coming from.

Thanks for the input.

willie
 
I remember seeing a similar post in the past couple of months... I seem to think it was a linkage issue after the body lift?
 
Mine's running rough after I installed a 2" body lift too..... what type of linkage issue???? I'm stumped.

RIZ
 
Sorry to mislead you guys, I was confusing a couple of different threads. I usually click on any TBI idle issue threads since I struggled for over a year resolving all of my TBI issues. The one I was thinking of had suspected a throttle linkage issue and had recently installed a 1" body lift, turned out not to be the culprit. I'm curious what the cause turns out to be...
 
Altitude. The body is at higher altitude and the reduced air pressure is causing idle problems...............

Seriously, there is a base idle adjustment. Its a mechanical adjustment that sets how much the throttle is held open when you take your foot off the pedal.

You set it with the IAC unplugged as I remember. Usually when its set wrong, you have too high an idle because the IAC is closed all the way but the throttle is still open too much.

Its possible that it got knocked out as you were moving things and the IAC is operating out of its sweet spot.

There are some threads on here somewhere that tell how to adjust it.
 
I do remember reading about setting the IAC and saved it in my favorites.

http://www.thirdgen.org/tpimod2

I was checking out the dist cap and rotor and thought that while I was in there I would swap out the ignition module with the spare I carry.

PROBLEM SOLVED ???

Now it idles as it should and doesn't surge anymore. Actually sounds damn good.

I'll take the module in and have it tested...If it fails then I'll get a new one....If it doesn't fail I'll get a new one anyway.

willie
 
wheels87k5 said:
I do remember reading about setting the IAC and saved it in my favorites.

http://www.thirdgen.org/tpimod2

I was checking out the dist cap and rotor and thought that while I was in there I would swap out the ignition module with the spare I carry.

PROBLEM SOLVED ???

Now it idles as it should and doesn't surge anymore. Actually sounds damn good.

I'll take the module in and have it tested...If it fails then I'll get a new one....If it doesn't fail I'll get a new one anyway.

willie
Click to expand...

:waytogo:
 
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