Struggling to Fix the SC

Phillio99

Registered User
Ok I can't seem to get the SC running. I've checked out all the vacuum lines and they are good, I have the Wynn Gaskets in so I don't think its a leak. Now, Ive run a compression test and both banks came out 150 or above. Nothing out of the ordinary. The plugs are AP4544 double platinum and the wires are good. I replaced the IAC and the TPS with sensors that came off a working SC. The coolant sensor was replaced as well. I keyed up the engine twice to do the MAF test and still nothing. The car dies at idle and will only run when the throttle is used to keep it running. I ran codes before switching out those sensors, I forgot the exact ones at school but they were regarding the specific sensors mentioned. Could it be the EEC? Any help would be great.
Phil
 
Phillio99 said:
Ok I can't seem to get the SC running. I've checked out all the vacuum lines and they are good, I have the Wynn Gaskets in so I don't think its a leak. Now, Ive run a compression test and both banks came out 150 or above. Nothing out of the ordinary. The plugs are AP4544 double platinum and the wires are good. I replaced the IAC and the TPS with sensors that came off a working SC. The coolant sensor was replaced as well. I keyed up the engine twice to do the MAF test and still nothing. The car dies at idle and will only run when the throttle is used to keep it running. I ran codes before switching out those sensors, I forgot the exact ones at school but they were regarding the specific sensors mentioned. Could it be the EEC? Any help would be great.
Phil

Have the fuel filter or regulator been replaced? Do a fuel pressure test and see what that shows. Also, if you can get a code scanner and check to see if there are any codes.
 
Reply

Yes I forgot I did a fuel pressure test 43 PSI at idle. If i allow the car to warm up for awhile it will hold a very low weak idle. I did a code scan too, I forgot the exact list of codes at school but I remember they were MAF, IAC, TPS, something about throttle snap, O2 sensor and coolant temp. Ill post the exact codes tommorrow. Possibly fried computer?
Thanks again,
Phil
 
Reply

Could it be a TPS voltage issue? I know there are three prongs, on the sensor, which ones do I want to test to find voltage? Should be in the neighborhood of .9-1 and when the throttle is opened it increases smoothly right? How can I adjust it if its not in that range?
THanks,
Phil
 
Reply

Ive been doing some research and it looks like 43PSI of fuel pressure is a little high for idle. Any ideas? Possible vacuum leak?
Phil
 
Phillio99 said:
Ive been doing some research and it looks like 43PSI of fuel pressure is a little high for idle. Any ideas? Possible vacuum leak?
Phil

I was thinking the same thing. Should be 35-40psi. I'd look at the fuel pressure regulator and see if it's bad. I bought one from Ford for about $65.
Make sure that's what it is before buying a new one.

If the regulator is bad, it could be allowing to much fuel and flooding the car out at idle.
 
Reply

Alright, at school codes with KOEO are 82, 63, TPS too low, 66 Maf singal CKT ground
KOER 72,No Maf 73, Maf Snap 74, Brake 12 Cn't control RPM 21, coolant temp 41, EGO not switching 91 02 not switching.
Those are the codes replace IAC, Coolant temp and, TPS, no change. IAC is ohming out at 10 ohms and I still can't get a TPS reading. Please Help.
Phil
 
That does sound like a lot of problems all at once. One problem might be causing another one though. Since you have already replaced some things with no change, I would suggest doing more testing on the parts that are showing bad, before buying anymore parts. You can go broke buying parts that way and still not get it fixed.

If you had an computer to switch yours with, that would let you know if it's the computer or some other problem. Are there any other SCers near you that you can borrow parts from to try?
 
Reply

Thats what I did with the IAC, TPS and the ECT sensors. Im thinking its pointing to whacky TPS voltage for the throttle snap code, and I remember reading if the MAF and the TPS aren't reading the same it can be trouble. NCRED thank for all the help. Any other suggestions?
Phil
 
what year is the car?
It might be the TB needs to be cracked open a little thats that my car need to idel or the IAC is gone bac or the adjustment is off.
what the car do if you give it some gas if it dies it's the fuel filter or regulator. 43 is a little hit at idel.
 
Reply

OK, set the TPS voltage and nothing. Same situation, when the car is started it dies out right away, to keep it running the gas pedal must be raced, (ie revving) When the car comes to a stop and the engine quits there is almost like a huff noise like when you exhale, not the goose honking though. I installed the wynn gaskets but i started from the bottom IC connection and went up, i didn't tighten them all at the same time. Possible vacuum leak? should i loosen all the IC connections then reconnect them this time tightening eachone a little at a time?
Thanks,
Phil
 
If you thing it a vac leak get some brake clean (as long as you did not paint any tubes with spray paint) and spry all the areas at joints with it as someone it trying to kept the motor running. If you get it to jump up in reves theres your leak.
 
Reply

I gave that a shot Jason, but since the thing is being revved to stay running i couldn't tell. Should I race the engine and keep it alive until it starts to warm up? The longest IVe kept the thing running is for a minute tops. Will i do any damage by constantly revving up to 3000-4000? It seems to me like this is never a good situation.
Phil
 
Stumped

Im really stumped, I guess Im gunna go over the IC tubes one more time to see if thats the problem, Ive been reading posts in the past and that seems to be common mistake. Intake manifold gasket maybe? I also have an 80mm Lincoln MAF that i was thinking of installing to see if it fixes the MAF problem. Is that a good idea?
Thanks,
Phil
 
Revs

At start up I have to blip the throttle to keep it running. 4000rpm is probably a little high more likely in the neighborhood of 2500-3000rpm. Still, thing won't hold an idle. Can i keep blipping the throttle like this so i can get codes again, I did it once before and it hold a really rough idle with 5 Hg inches of mercury. Is it ok to blip like this, Im worried im doing damage.
Phil
 
With that low a vac reading I think you've got a big vac leak somewhere.
Until you get it to idle better than that I dont think codes will be that usefull to you. Have you tried unpluging the MAF sensor? if the MAF is bad the engine may not idle like your describing and unplugging it will help to run. Should that not help try unplugging the TPS, if neither one of those helps you at all you have a big vac leak.
 
REply

Any idea on the location of the vacuum leak, I assume it would have to be pretty large. I doubt it's the IC tubes becuase I do have the Wynn Gaskets on but I am in the process of taking all the IC tubes and reinstalling them. Hopefully that will help. Could it possiblely leak at the intake manifold gasket? Would it give me such a bad idle condition?
Thanks,
Phil
 
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