944 won't start

jblobner · 12-22-2018, 11:48 PM

1987 944 NA. Had been running perfectly, until last week. I started it and the RPMs jumped from 200 to 800 several times, then leveled off at 900. Took it on a test drive no issues at all. The next day it started fine and RPMs at idle were normal, but the throttle was only providing power for the the 1st 2/3rds of pushing the gas pedal. The last 3rd would cause a loss in power. Shut it off came back a few hours later it started fine again, but I shut it off and tried to restart it and it would not fire up. After several attempts I could smell gas. Let it sit a few hours thinking it was flooded or something, but it still won't start. Any thoughts of where to start looking.

Swennydawg · Swennydawg's Garage

Assuming that all is OK w/belts etc. make sure that you have spark, air flow and that the fuel is reaching the injectors. So some basic trouble shooting then you can advance to a more "refined" trouble shoot. I just checked every system on my 924S only to find dirty gas and clogged injectors.

jblobner · 12-23-2018, 09:05 AM

Yes it's getting spark. After sitting over night it started, but just once. It won't start again. Could the alternator be causing issues. I notice the battery was low and volt guage was reading just above 10. The battery is brand new.

matt1415 · 12-23-2018, 03:41 PM

Quote:

Originally Posted by jblobner

Yes it's getting spark. After sitting over night it started, but just once. It won't start again. Could the alternator be causing issues. I notice the battery was low and volt guage was reading just above 10. The battery is brand new.

When you say it won't start do you mean it cranks but won't turn over or is it just not cranking period?

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PHillary · PHillary's Garage

Try giving it a jump start! If it starts then you know you have power issues

DannoXYZ · 12-24-2018, 09:18 PM

Vacuum leak after AFM

jblobner · 12-29-2018, 07:07 PM

It cranks but won't turn over. It struggles to crank as if the battery is weak, but it's not. Brand new battery (12.7 volts)

jblobner · 12-29-2018, 07:15 PM

Put a jump on it same result.

jblobner · 12-29-2018, 07:16 PM

Checked for a leak couldn't locate one.

PHillary · PHillary's Garage

Starter....have your started tested.....Autozone its free

Jfrahm · 12-30-2018, 08:10 AM

If it's struggling to turn over even when jumped with a good battery and good cables look for something like a seized alternator or AC or PS, or some other drag. Camshaft maybe.

I suppose the starter could get weak (very uncommon though) but that would not explain the running problems you also observed.

Try turning the engine with a socket wrench, it should be pretty easy to turn but for some bumps when you hit compression and you should be able to let the compression bleed off as you slowly turn past these spots.

matt1415 · 12-30-2018, 01:17 PM

Check the main ground in the battery compartment. It's the one that leads directly from the negative terminal harness on the battery. This ground can cause many electrical issues if it becomes corroded. Simply remove the bolt holding down the strap to the body and clean all points of contact with some fine sandpaper or a wired brush. That's where I would start.

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Bukowski · 12-30-2018, 01:53 PM

What parts are new?

Check my posts for details on cleaning the engine ground. There’s a voltage drop test there (thanks djnolan!). The symptom was sorta like a dead battery.

jblobner · 12-30-2018, 03:56 PM

Quote:

Originally Posted by Bukowski

What parts are new?

Check my posts for details on cleaning the engine ground. There’s a voltage drop test there (thanks djnolan!). The symptom was sorta like a dead battery.

Rebuilt steering rack from Ian at 944 and rebuilt Bosch alternator. Relplaced a Bosch. I will check your posts. Thx.

PHillary · PHillary's Garage

Quote:

Originally Posted by Jfrahm

I suppose the starter could get weak (very uncommon though) but that would not explain the running problems you also observed.

It is the starter solenoid which is usually the piece which becomes weak and non responsive or slow to engage on the starter, from old age and general weathering associated with non-use over a period of time.

Once we get the car running then we can diagnose the rough running issues he is experiencing.

Bukowski · 12-31-2018, 05:03 AM

How’s the alternator belt? Is it tight? Mine loosened slightly after installing alternator.

If you can get the Harbor Fright alternator/battery tool, it’s about five bucks.

Distributor cap, ignition cables, spark plugs - they could give spark, but if they’re sorta bad, could this be it? I mean they are how old?

Good luck

jblobner · 12-31-2018, 05:40 PM

OK I'll check the starter solenoid. As I was checking the vacuum lines I got a pretty shock from one of the plug wires. Rubber boot has a good sized crack exposing the wire. So, I'll be replacing that. I'll update once I get the new ones.

jblobner · 12-31-2018, 05:42 PM

The belt is tight but squeaks a little. Thanks for the tool suggestion I'll pick one up.

jblobner · 01-02-2019, 01:54 PM

Ok I have checked all items you guys have suggested and replaced the fuel pump. Same issues. The first revolution of the starter is slow but it kicks in and starts. Once it's started there is no power when accelerating and the engine oil light comes on. Oil is to the top lines on the dip stick.

Thoughts.

Jfrahm · 01-02-2019, 04:01 PM

So the engine is not hard to turn by hand?

Crank the starter with the coil wire removed and see if it spins up faster. If so, check the rotor and cap and the plug wire order, connections, etc.