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Sporadic loss of power - suspect fuel issue 700 1990

Howdy folks.

So about a week ago, I tore apart my dash to get to the heater core. As I removed the fuse/relay tray, I saw a jumper wire running from my fuel pump circuit to the sunroof, which I'm sure doesn't belong there. I think it was a hack-ish fix to a failed hybrid fuel-pump circuit on an old ECU. I removed it, and the car ran great for about a week.


Finally actually swapped cores last night and flushed (ran it around the block with tap water in it), then filled with Zerex G-05 and distilled water.

Now, I'm getting weird power losses at steady cruising speeds - any engine speed, it will start to bog down and moving the gas pedal does nothing unless I push it far enough to kick down a gear. If I am accelerating, it doesn't do it. If I'm cruising it does it the most, and sometimes if I am decelerating.
I got a Check Engine Light (CEL) and it threw two codes: 2-3-2 and 1-3-3.
I've never seen a 1-3-3 code before. The FAQ says that's 232 is too rich/lean at idle and the 1-3-3 says faulty TPS. I did get a high idle when I parked just after the CEL came on.


I pulled the AMM to try to get it to limp-home mode, and of course the idle jumped to 1300 when I did. Then I tried to drive off and it died. Restarted and died again. AMM reconnected it runs.
So I thought it must be a vacuum leak. In the process of doing the heater core last night, I moved this vacuum line that runs from the manifold on a 1/2" line to a check valve and then to a tiny vinyl line that runs through the firewall and supplies the vacuum reservoir mounted under the dash.
I checked around by spraying starting fluid at every vacuum fitting and air intake junction, and nothing made a difference. I don't think this fits the symptoms for the ignition amplifier overheating (plus it's 70F here, and I replaced the thermal paste 3 years ago. I do have a spare.).

What I think it might be:
-The jumper wire was critical to feed power to the fuel pump (with it attached, it runs constantly in KP2) because my non-pink label ECU somehow failed. The ECU is from 92. Don't recall the code off it right now, but it's easy enough to check.

-I caused a massive vacuum leak that I can't find somehow or damaged the check-valve.

-I messed up a wire to something like the Engine Coolant Temp Sensor that feeds the ECU somehow in the process of doing things.

-My brick is possessed by demons angry that I removed the original heater core

-The TPS is misadjusted so badly that it's playing with the IAC valve while I'm cruising with a part-open throttle. I think the easy fix for this is to simply disconnect the TPS (assuming it idles at all then). I cleaned the throttle body (TB) about 5-8K miles ago and replaced the TB gasket. I also adjusted the TPS when I did this. Maybe I left the adjusting screws slightly loose and they're managed to work their way completely loose so the TPS can flop around.

-The Radio Suppression Relay (RSR) has very haggard wiring from my engine swap 3.5 years ago. I pulled a pigtail and relay from the local wrecker on my way home. When I held my hand on the RSR and revved the engine, I could feel it sort of clicking, but not a solid click, more of a vibration or clicking on and off.


Can anybody help me narrow this down? I think that right now, I'll go replace the harness for the RSR after reinforcing this new-to-me used relay's solder. Then I will see if it runs with the TPS disconnected (or IAC). Then I will reconnect that jumper wire from fuse 11 to fuse 10 that I swear should not be there.

Cheers








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    Sporadic loss of power - suspect fuel issue 700 1990

    New thread started. CPS seems fine. New one installed, no problems with the engine running when I play with the wiring.

    I suspect it might be the RSR I pulled from the JY. It's jumpered right now.

    More details on the new thread:

    https://www.brickboard.com/RWD/volvo/1594057/740/760/780/replaced_cps_stumbling_powerloss_still_persists.html








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    Sporadic loss of power - suspect fuel issue 700 1990

    I had similar problems which turned out to be bad wiring at the plug to the RSR. The sorry rubber around the terminals that hold them into the plug had deteriorated. The fix was to replace the the plug with a good one. Hope this helps. Larry








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      Sporadic loss of power - suspect fuel issue 700 1990

      Ah, thanks for the input. I did have some pretty haggard wiring at the pigtail. I went by the JY on the way home and got a relay with about a 16" pigtail attached, reflowed the solder on the relay, and replaced the hack job that was my RSR wiring before with heat-shrink butt connectors. Heh, butt connectors :P

      I'm convinced it's the CPS. It's cheap enough and my cranking to start has been slightly longer than usual the several months or maybe longer. Plus, I pulled on the CPS wiring today and it just about died at idle.








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        Sporadic loss of power - suspect fuel issue 700 1990

        That is a good sign the CPS is at fault, is there any insulation missing or cracked.
        Dan








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          Sporadic loss of power - suspect fuel issue 700 1990

          I replaced the CPS today - no change.

          I am hoping it's the wiring. I plan to swap the old cps back in and splice the wires together. Rockauto offers a new engine-harness side pigtail, and the volvo at the wrecker's here has one too.

          What's with the bare wire in the wiring bundle?








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          Sporadic loss of power - suspect fuel issue 700 1990

          There isn't, but there's a good bit of kludgy old oil built up on the bottom few inches of it. It's only 4 years old, insulation looks good. I replaced it as preventive maintenance. The original had been in there for .... sheesh, must have been 10 years.

          I think I might have routed it wrong and it was somehow under strain, or I put the plastic clip meant to hold it in place in the wrong spot.








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          Sporadic loss of power - suspect fuel issue 700 1990

          FYI. Mine #1 fuse also overheated the block. Know issue. I added a fuseable link to it and also the blower motor fuse(melted base also). Can't remember which one but one of them has a jumper feeding another fuse. So you just can't cut the wires and add the link. Check the FAQs, it's was covered there.
          --
          Post Back. That's whats makes this forum work.








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    Sporadic loss of power - suspect fuel issue 700 1990

    Updates:

    -Tested TPS with OBD1 test mode 3&4. all sensors checked out, all things made noise - injectors, CSI, IAC, but I did not hear the RSR or fuel pump come on. Maybe it did, but it seemed like it skipped them.

    -replaced wiring pigtail and replaced RSR with used (reflowed/added solder)
    -reconnected fuse 10/11 jumper
    -Loosened and retightened injector ground bolt (will remove and do a real cleaning tomorrow)
    -disconnected TPS

    I'm now leaning towards having damaged the CPS by being rough with things bundled to it on the firewall (the 1/2" climate control vacuum line especially). Nothing else makes much sense to me.

    The tach drops simultaneously with the loss of power. Moving the pedal does nothing. It's only a problem at part load, not idle nor full load (WOT or enough to be in boost). It's a very brief loss of power, but it starts to happen more and more often the longer I drive. Driving constantly accelerating a little or decelerating a little helps, but that's kind of inconvenient. I can't cruise at any steady speed.

    If anybody has even a wild guess, please say so. The only thing I can think of having touched that could affect ignition/fuel is the wiring that runs along the firewall behind the engine where the climate control vacuum line runs.


    PS I was at the JY today and saw a gold 780 bertone. Body was in good condition, 240,000 miles, looked like it had a b230ft..? and the interior was pretty trashed. I wonder if that moon roof would fit my car...

    Cheers

    PS: Also, the Fuel pump relay and RSR aren't clicking while I'm driving.
    Reading some other posts, CPS seems most likely.
    Also replaced the #1 fuse, which was a little heat-warped, and hard to remove.







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