924Board.org

loddyjr · Joined: 05 May 2012 Posts: 20 Location: Kingwood, TX

OK so if you have seen my previous post I did allot of routine maintenance to my 1982 924 over the last two days. Fuel filter, timing belt etc. During a recent test drive I experienced what feels like a miss fire at high RPM's above 3K? I'm not sure what this is. My fuel pump is making a loud wine all the time and I have not touched any of the fuel injection system other then the filter. I do not experience this problem when reving up the motor under no load? Any help or direction would be appreciated. I believe this could be an issue with the accumulator but I'm not sure. I have read Rasta Monsta post from the newbies section and I did adjust the idle mixture adjustment screw to achieve 900 RPM during idle! I did this with the engine warm and turned it about 3/4 full turn. I was having idle issues this seemed to solve the problem! I have not had a chance to fully test drive the car as it has been sitting for years so I changed all the fluids, belts, filters, spark plugs, plug wires etc. Did I mess up by adjusting the idle mixture screw? Seem like I maybe running lean cause when it bumps around at high RPM there is allot more potential power. Plz let me know your thoughts and I apologize for the discription I'm new to the 924!

joejax · Posted: Mon Sep 03, 2012 12:37 pm Post subject:

Did you adjust the idle or the air/fuel mix? I would assume the idle. A/F mix requires a long 3mm allen wrench inserted into the small hole on the air filter thingy.

At any rate, if the car has been sitting, you may need to go through the fuel delivery system and clean everything being careful to not mess up anything.

May want to check the injectors for proper spray pattern and rate of delivery.

Have you checked, then double check, then go back and check again for vacuum leaks? Seems these cars don't like vac leaks.

I still struggle with mine keeping it running right. I have to run high octane gas, feed it Techron cleaner every once and awhile, and try to keep it running as cool as possible.

I am convinced that this thing hates to run during the summer. When it is hot out, I tend to have more stuttering and not wanting to start. Was running a coolant additive for lower temp, busted a hose so that was inconclusive.
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I got nothin'
Uhhh...you got any pics?

loddyjr · Joined: 05 May 2012 Posts: 20 Location: Kingwood, TX

joejax · Posted: Tue Sep 04, 2012 12:11 am Post subject:

That screw on the upper intake is the idle. The A/F screw is behind the fuel distributor on the air intake, there is a small hole there which requires a 3mm allen to adjust.

I doubt adjusting the idle would make it run any worse, sounds like you may have a fuel issue, vac leaks, and/or timing problem.
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I got nothin'
Uhhh...you got any pics?

!tom · Posted: Tue Sep 04, 2012 8:45 am Post subject:

Do a fuel flow test to verify:
1) Even fuel flow to all cylinders
2) Sufficient flow

The specs. are available in Hayne's and through a search here.
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78 924 NA
5-lug

loddyjr · Joined: 05 May 2012 Posts: 20 Location: Kingwood, TX

Tom thanks for your comments I need to get a manual ASAP. I now know for sure I have a fuel problem! My inline fuel pump sounds like the bearings are shot! I decided to tap on the fuel tank and well lets just say that was a bad idea. My car will barley idle now so I'm going to pull the in tank pump, and the inline fuel pump. This will also allow me a chance to clean out the gas tank as the car has been sitting for a couple years. I believe the in tank pre pump is still in good condition but the inline making all the noise concerns me. I have posted a WTB under the parts forum to try and locate one at a reduced cost. I hear nightmares about the in tank pump and changing it so i will do my research b4 hand.

Thanks everyone for your comments I really want to get her on the road hopefully I can get all the parts by next weekend if not I will be rebuilding the brakes!