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View Full Version : Help! Won't start and running rich



dsteph79
04-27-2003, 09:58 AM
Brand new SC owner needs help.Had the car started twice but
it is pouring blask smoke out have to keep it half throttle to keep
it running.Now I cant get it started.Pulled three plugs and they
were gas fouled.Put hose on fpr and turned it over no fuel coming
out so I dont think the fpr is bad.Could it be o2 sensors?Any help
would be greatly apreciated!

Duffy Floyd
04-27-2003, 10:39 AM
Check to see if the crankshaft pulley is wobbling....if so the harmonic damper broke.

No way it could be O2 sensors...until you get to NOT they are off line as far as engine control is concerned because you are in open loop.

kevenj90sc
04-27-2003, 02:09 PM
check fuel pressure. if it's too high, due to bad fuel pressure regulator, it will pump raw gas into the engine. Should be around 35 to 40 psi running. A buddy had a similar problem on a 90 F250 with a 460, his regulator was bad and he was running 140 psi fuel pressure!......raw gas was dripping out of his tailpipe.........

Duffy Floyd
04-27-2003, 02:36 PM
Good point to check but the stated fuel pressure is incorrect. Idleing with say near 20" vac the correct fuel pressure should be around 30 PSI. All SC's have a 2.7 Bar (39.508 PSI) fuel pressure regulator that maintain a 39.5 PSID across the injectors, When idleing you are basically at a "negative pressure" so the FPR will reduce the actual fuel pressure to maintain the required PSID.

kevenj90sc
04-27-2003, 06:13 PM
hmmmm.....well my Ford shop manual from Helm says fuel pressure specs are 30-55 psi running and 35-45 psi with the ignition on , engine off. Mine goes to about 38 psi when you turn on the key and stays about the same running, then goes up just a little when you shut it off. My friend's '89 does exactly the same thing....

Duffy Floyd
04-27-2003, 08:56 PM
Not sure where in your Helms you are looking but I am looking at the 1990 Engine/Emissions Diagnostics Manual and it lists for the SC 30-40 PSI Engine running and 35-40 PSI Key On engine off.

What you read with the engine running at idle is dependant on the amount of vac. you get. You are supposedf to get the 2.7 bar with the engine off but key on but it can be lower if the pump has shut off (like it will after 3 seconds with no engine start detected by the EEC/PCM)

dsteph79
04-27-2003, 09:40 PM
Thanks for the response guys I will check the harmonic balancer
and the fpr. Is the fpr from a standard 3.8 the same as a SC?
What about the sensors are they the same as a SC? I have a
91 standard 3.8 parts car and a 91 cougar xr7 parts car.

dsteph79
04-27-2003, 10:17 PM
Ok just went out and checked the harmonic balancer it seems to
wobble just a little bit could this be the problem? Does this car
have a map sensor or a bap sensor as stated in the haynes
book? Does the bap look just like map sensor?
THanks for your help. Davey Stephens

dsteph79
04-27-2003, 10:20 PM
Where is the best place to get a harmonic balancer?

Duffy Floyd
04-27-2003, 10:49 PM
All SC's have BAP sensors mounted on the passenger side of the firewall. In my mind the harmonic balancer/pulley should not wobble at all. The effect of the wobbling is to alter the timing which is why I suspected it in the first place. You could be off so far now thet there is allot of unburned gas in your exhaust system.

As far as where to buy???? Depends on how long you intend to keep the car. If you might only own it a few years I would go stock with the Ford Unit. If you intend to keep it or mod the motor then got to recommend a BHJ Damper which you can get from Blue Tongue or Super Coupe Performance or I think BHJ themselves.