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First time guy finally on the road! Need help with next step

 
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gml  



Joined: 04 Mar 2021
Posts: 117
Location: Ontario Canada

PostPosted: Mon Jun 14, 2021 11:41 am    Post subject: First time guy finally on the road! Need help with next step Reply with quote

Today I finally got the coupler sleeve torqued in and got all the rest back installed, and took my 924 around the block!! What a feeling to have it running. My work is far from done though.

It starts up no problem but runs quite badly. It feels like the throttle is in and out. When it first starts and idles, it tries to die unless I give it gas — then eventually it idles on its own, but it is low, at around 600 RPM on the tach. A lot of the time the gas pedal does not feel responsive — I can floor it and it struggles to reach 3K RPM. At one point when I drove around the block, it really started struggling, I couldn't go faster than 20 km/h and I was flooring the gas, it wasn't revving higher than 2K RPM and felt like it was about to stall. Does this all sound like a vacuum leak or is there something else I should look into? I have a HPSI silicone vacuum hose kit ordered. It does look like at least some of the vacuum lines were already replaced, looks like with rubber fuel line hose...

It also is very loud and smells strongly of gas fumes. One of the previous owners installed a Magnaflow exhaust, but I heard that people found them to sound pretty much like stock. It was coupled to the engine exhaust with a steel clamp, is it most likely my fault for not closing it up properly, or is this another common issue with a different cause? Are the fumes likely related to my gas tank re-install?

Finally, there is a buzzing sound in the cockpit from the moment I put the key in and does not stop even when its driving around. The low fuel light was on, and the driver door doesn't quite close — would these be the cause of that buzzing?

Thanks for all your help as I've posted questions throughout this journey! With some help I'm hopeful it will be humming along smoothly soon.

Edit: got it running on day 50 of owning my 924, and wrote my 50th 924board post to share the good news on the same day
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George

1982 924 NA 5-speed
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jacobroufa  



Joined: 18 Nov 2016
Posts: 529
Location: Belvidere, IL

PostPosted: Mon Jun 14, 2021 9:54 pm    Post subject: Reply with quote

Congrats! I think there are a few answers you might be looking for in the 924.org FAQ: http://www.924.org/techsection/GarageFAQ.htm

Sounds like you have some tuning to do. Be sure to replace all the vacuum lines first! This CIS system is very vacuum sensitive in its tuning.

I don't know if others have suggested to you yet but our cars seem to respond well to the Techron fuel additive. To aid in cleaning the fuel system you can dump a bottle in the tank with your next fill up.

The door buzzer comes on with key in the ignition and the door open, so it sounds like that's what you've got going on there.
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Cedric  



Joined: 27 Aug 2004
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PostPosted: Mon Jun 14, 2021 10:20 pm    Post subject: Reply with quote

I think a measurement of fuel pressures is more or less the only way to go here, it can be an endless trial and error if those arent correct.
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gml  



Joined: 04 Mar 2021
Posts: 117
Location: Ontario Canada

PostPosted: Tue Jun 15, 2021 12:10 am    Post subject: Reply with quote

Thanks for the reminder, I will definitely run through the tune-up section on the 924 FAQ. I think a fuel system clean up is just the ticket as well, I'll grab a bottle of Techron.

The driver door being broken must be causing that buzzing then, I will figure out how to disable that on my 82 model. I'll only have that fixed once the car is roadworthy.

Hoping a tune up will solve most of my issues but I will share my progress. I'd be happy to do a fuel system diagnostic if need be.
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George

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gml  



Joined: 04 Mar 2021
Posts: 117
Location: Ontario Canada

PostPosted: Wed Jun 23, 2021 2:21 pm    Post subject: Reply with quote

Bought this Pelican Parts tune up kit: https://www.pelicanparts.com/More_Info/RN9248182.htm

So far I've changed the spark plugs and the fuel filter.

When changing the spark plugs my old ones had a threaded stud at the terminal (top) but the new ones had a rounded terminal. Turns out they are removable. I used slip-joint pliers to grip the terminal and twist it off so that I could pop in the spark plug caps. With the rounded terminals the caps wouldn't fit on properly.

To change the fuel filter I bought a 19mm flare nut wrench to counter and hold onto the filter nuts while I twisted off the fuel line nuts with a regular 19mm (top nut) and 17mm (bottom nut) wrench. I wasted so much time trying to get the bottom bolt tightened. Lesson learned: make sure you can hand tighten as much as possible since the bolt can be finicky to thread in — I managed to hand tighten that bottom fuel line bolt until almost all the threads were out of sight and then just did a few small angle countered wrench rotations until it felt quite tight. Removing the air filter and housing was essential to get the wrench angle but I don't think removing the intake would be worth the trouble at all (I was tempted to do this as I idiotically struggled earlier, when I was basically tightening a bolt threading into nothing......)

As predicted, the fuel dripping out of the old fuel filter had a lot of rust particles and debris due to the poor condition of the previous (replaced) fuel tank. The car seems to be running way better with the new fuel filter! It didn't start at first but I believe as the fuel line refilled it started and then gradually began to run much better.

When I play with the throttle on the engine it seems quite responsive, but pressing on the gas pedal it doesn't seem responsive. Specifically, it runs okay at medium gas, then flooring it, it actually revs down. Hoping that issue is gone now that its running cleaner, I'll be driving it a bit tomorrow to confirm. I am waiting for my silicone vacuum line kit but until then I am not sure I have any more tune ups I'm eager to do.

Hope this helps another amateur mechanic on their 924 tune up!
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Glemon  



Joined: 05 Jan 2016
Posts: 262
Location: Lincoln, NE

PostPosted: Fri Jun 25, 2021 3:16 pm    Post subject: Reply with quote

Check the door hinge mounts to the body, they can crack/fail. Check the intake snorkel, they crack. Others here have a lot more expertise on the Bosch fuel injection and ignition.
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gml  



Joined: 04 Mar 2021
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Location: Ontario Canada

PostPosted: Sat Jun 26, 2021 4:05 pm    Post subject: Reply with quote

Thanks Glemon. My driver's door hinge is most certainly broken, I need to take it to the shop later to get it professionally welded. I noticed a small crack near the entrance of the intake snorkel but it gets clamped. My cigar vacuum leak testing today didn't reveal any cracks in that part.

Right now my problem is that the car idles quite low. When I apply throttle and release it, it goes very low and almost stalls. Other than that it has been running much better with the new fuel filter. Today I replaced some of the vacuum control lines and other small diameter vacuum lines, it may have slightly improved. I will try to dig around a bit more for common fixes before I dive into trying to pressure test the whole fuel system.

Waiting for a new odometer gear to come in, right now the instrument cluster is pulled out since I wanted to count the teeth on the broken gear before I ordered the replacement (it has 10). The speedometer bounces around a bit so I might pull out the cable and re-grease it when I get the speedo back in place.
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