Question on SC CIS?????????????

damian911 · 05-21-2011, 09:17 AM

Hello all, My 83sc has been acting up lately when i shut it off after a drive and i restart it. The car immediately starts up no problem but it has a hard time running smooth like it coughs and spudders pretty hard until i drive it 3 or 4 miles and it evens out. Is it the fuel accumilator??......thks for any imput out there....damian

70SC · 70SC's Garage

Debris / water in the fuel . Ethanol sucks , up moisture . Hygroscopic

Joe Bob · Joe Bob's Garage

Filter and/or low fuel pressure.

damian911 · 05-21-2011, 08:36 PM

thks for the replys...........first thing i did was chang the fuel filter and it wasnt it...soooooooooo

damian911 · 05-21-2011, 08:41 PM

low fuel pressure hymmm yea maybe ....how can u put in a fuel pressure gauge anyone know???

Joe Bob · Joe Bob's Garage

Got spark? Try quick start,,,,if it starts it's a fuel pressure issue....

psalt · 03:19 AM

Damian,

The fuel accumulator is a device to hold pressure for a restart, if the engine starts right away, it is not a problem. Start with the basics, a cold engine needs a very rich mixture or it coughs and sputters. A hot engine is the opposite and often won't start if the mixture is too rich. What could be causing a too rich mixture on a hot restart ? In your case several things. There are two temperature related switches that alter fuel enrichment that should be tested. If the switches are telling the ECU the car is cold when it is hot, you get too much fuel. My advice would be to test the electrical part of the CIS lambda system on your car, and observe the duty cycle when this is happening. If the ECU is getting the correct signals and the duty cycle readings are correct, I would check the control pressure and the WUR. You don't say how hot hot is, but a hot engine should not be getting extra enrichment from lower control pressure. I would be checking the pressure cold, during warmup and after a hot restart. The bimetalic spring or the heater could be failing and the extra enrichment does not disappearing until you drive several miles and the engine gets really hot.

stealthn · 05-22-2011, 07:35 AM

Bang your WUR with a rubber hammer a couple of times and see if it goes away.

Bob

damian911 · 05-24-2011, 10:28 PM

sorry i forgot to say my warm up regulator has been unhooked since early winter when it ran quicker with the elect. connection...my computer is unhooked and of course no 02 censor cuz im running headers into a m&k exhaust....so since alot of these things are unhooked and havent been hooked up that elimantes alot of things...so thats why i was guessing the fuel accumalator??? any suggestions?

damian911 · 05-24-2011, 10:31 PM

Like i said it starts and runs pretty good when i leave for work but if i have to stop for more than a few minutes the car starts no problem but runs like crap until i run it for a few miles like 4-6 miles and all the bugs go away and almost back to normal.....

j911brick · 05-24-2011, 10:44 PM

Quote:

Originally Posted by damian911

sorry i forgot to say my warm up regulator has been unhooked since early winter when it ran quicker with the elect. connection...my computer is unhooked and of course no 02 censor cuz im running headers into a m&k exhaust....so since alot of these things are unhooked and havent been hooked up that elimantes alot of things...so thats why i was guessing the fuel accumalator??? any suggestions?

You got it backwards. All that stuff being unhooked is probably a large part of your problem.