Fuel Issues Hope and Patience fading, Changed Many Parts

RedMosesSC

Registered User
Fellas and Ladies,

This is my third thread on this Prob, Car hasnt moved in 2 months, Been paying Insurance and sunk several hundred in parts.

After all that has been done, the car now starts and drives. When you get on the road and give it more than 50% throttle is stalls. WTF?

Thought it was the ECU, it is now Obsolete. Found a Place that rebuilds them (ECUDirect.com) got it done for $169. Put it in today, same problem. And spittin out NO CODES

Before that Changed the Fuel Pressure regulator to get the car started.

Before that changed the KOER pack (DIS), Cam sensor, crank sensor and so much more that i dont even remember what i did.

Could it be the MAF? what can i be? Im stumped, my mechanic is stumped. Im loseing alot of money and going Gray. If i cant figure it out soon it may become a nice parts car for you guys and ima have to get a Freagin Rice Burner and Junk my Baby that ive given all my Money and time for the last 5 Years. This is the last straw.

Thanks for all your help yall, the SC community is full of great peeps. I wish we all lived in one town, life would be better.

:(
 
RedMosesSC said:
Fellas and Ladies,

This is my third thread on this Prob, Car hasnt moved in 2 months, Been paying Insurance and sunk several hundred in parts.

After all that has been done, the car now starts and drives. When you get on the road and give it more than 50% throttle is stalls. WTF?

Thought it was the ECU, it is now Obsolete. Found a Place that rebuilds them (ECUDirect.com) got it done for $169. Put it in today, same problem. And spittin out NO CODES

Before that Changed the Fuel Pressure regulator to get the car started.

Before that changed the KOER pack (DIS), Cam sensor, crank sensor and so much more that i dont even remember what i did.

Could it be the MAF? what can i be? Im stumped, my mechanic is stumped. Im loseing alot of money and going Gray. If i cant figure it out soon it may become a nice parts car for you guys and ima have to get a Freagin Rice Burner and Junk my Baby that ive given all my Money and time for the last 5 Years. This is the last straw.

Thanks for all your help yall, the SC community is full of great peeps. I wish we all lived in one town, life would be better.

:(

Just a guess would be fuel filter or pump. Sounds like it's not getting enough fuel to support the boost. Get fuel pressure checked as it can have enough pressure to run the car, but not enough under boost conditions. Good luck!
 
Sounds like a fuel delivery problem, or lack thereof. It's the only thing that makes sense if it runs and idles ok but has problems as you increase the demand for more gas. Sounds like the fuel delivery is not keeping up with the demand.
You could even check for a bent of crushed fule line somewhere under the car. I know it sounds off the wall, but I ran over road debris once and it kicked up and dented the fule line, hindering fuel delivery at WOT(wide open throttle). Pulled my hair out for almost 6 months and then it hit me. Sure enough, found the crushed line 2 minutes after I climbed under the car.
Sometimes ya just gotta think off the wall. ;)
 
sounds like a problem i just fixed.. I changed everything you did and more. Finally out of desparation i removed the harmonic balancer, it had spun on itself and was tight with no wobble. Take it off.. you have nothing to lose
 
RedMosesSC said:
WHere exactly is the harmonic balancer?
It is behind the crank pulley. Before you pull it apart start the car and watch the pulley and see if it has any wobble to it. When mine went it still ran good but it had no power. If the balancer is bad buy a BHJ balancer and have it forever.
 
I have to Check on that Fuel Line comment, its possible that its bent but the Fuel Pressure Reg has been changed and checked, so we are getting pressure. The Harmonic Dampner doesnt sound like it could be the issue but i will have take a look at it.

The only logical thing (even though nothing is logical on this motor) seems to be the MAF. I need to buy one, does anyone have a used one or cheap one they are willing to part with for a 93 SC Auto?

Thank Fellas
 
after reading your many post ..you mention it firing on 4 of 6 cyclinders ....
do you know which 2 are not firing ? coil pack fires cyclinders in pairs [1-5] [2-6] [3-4] ...now disconecting the wires on the coil pack .....one at a time with insulated pliars ...you can see and hear the spark jump ..and hear/feel it's effects on a running motor ...so you can confirm if they are all firing @ the coil pack ..if you find a pair listed above not firing ..then you have electrical issues...if you find ...say #2 and #3 are not firing ..2 cyclinders side by side ..then head gaskets could be in question or spark is jumping via bad or burnt wires.or 2 wires say like #1 and #4 would likely be wires or plugs .....after confriming you have spark to all cyclinders from coil pack ..and still not firing on all cyclinders ....check ...the ones.. that don't seem to effect rpm .....when disconnecting the leads on the coil pack ..check plug wire first... then pull spark plug..... see if the electrode is still on the plug ..or melted from running too lean ...also listen for spark jump from the wires may have melted through ...also check your plug gap
which you set at ? ....dave
 
Last edited:
RedMosesSC said:
I have to Check on that Fuel Line comment, its possible that its bent but the Fuel Pressure Reg has been changed and checked, so we are getting pressure. The Harmonic Dampner doesnt sound like it could be the issue but i will have take a look at it.

The only logical thing (even though nothing is logical on this motor) seems to be the MAF. I need to buy one, does anyone have a used one or cheap one they are willing to part with for a 93 SC Auto?

Thank Fellas

If you think it's the MAF just disconnect it. Don't start replacing parts because you "think" that's what it is. That isn't troubleshooting, and will cost you way more in the long run. You said the fuel pressure was checked well what was it? and did it rise with boost?

Jeff
 
No codes (make sure you pull them, don't assume there are not any just because you don't see a light) typically means a mechanical problem.

Obviously, just swapping parts isn't going to solve the issue. So you should re-adress all parts of the system piece by piece and start eliminating issues.

Maybe start with a better description of the problem. I.E. what does "stalls" means.
Does it sound like a fuel problem or a electrical problem? I.E. Instantly stalls, tack drops to zero or engine sputters and dies.

You can test if the MAF is the cause of the problems by simply disconnecting the MAF connector and running with it disconnected. The EEC will plug in some default values for that, throw a code, but should run o.k., not great, but o.k.

Have you verified fuel pressure at the rail? You should get a gauge you can read while driving and you can see the pressure when you do your greater than 50% throttle opening. A bad regulator can show good pressure at idle and fall on it's face when demand occurs. Same thing can occur with the fuel pump. It can maintain pressure at idle, but can't flow enough at greater than part throttle to maintain pressure.

Get back to basics on trouble shooting this.
 
:( In my past posts i had the problem of two cylinders not firing, that was remedied by replacing the DIS and KEOR pack.

Car was running 100% for about 4 weeks, one day i would start the car, put it in drive and it sputtered and Back fired. Started changing parts and eventually got the car to run but stalls when u apply Gas.

I dont have the exact number of fuel pressure because my mechanic is doing most of the labor. He changed the Fuel Pressure Regulator and thats wat got the car started, so i am assuming he made shure the pressure is gud and it followed with Boost, although it sounds like that may be an issue becuase it stalls wen given throttle.

I just dont know wat to do, runnin out of money and patience.
The Motor was rebuilt 30 K ago Tranny was Rebuilt 50 K ago. INterior ive never seen on another SC, top 1/4 is leather bottom portion is heavy stiched Black and Grey Cloth. I really dont wanna part with it but i just might if u any of u guys are unterested. I wanna see my baby of over 5 years in Gud hands and whos better than you guys. its got 130k on the odometer, bought it with 70K and gave it alot of love. If u can figure out the prob its a great driver, otherwise theres tons of great parts on it. Im in Queens NY if any one is interested. If i cant figure this out in the next week its goin on ebay if no one shows interst.

Thanks
 
We'll, you shouldn't have allowed the mechanic to go hunting for issues rather than solutions.

Fuel pressure could be fine at idle but fail at road speed due to a bad pump or blockage in the tank restricting fuel flow.

Heck, it could even be a big vacuum leak.

Ever watch Texas Hold'em tournaments on TV? I'd say your Pot Committed so don't give up now. ;)
 
I was leaning towards a vacume leak ...but first was wanting to make sure it had spark ...and plug/ wires were good ..I use to have one wire fall off the plug on mine..and it didn't like boost when it fell off ...no matter how hard I pressed the gas and swore at it ..same with a vacume leak ....dave
 
I dont think its an issue with the Spark, becuase that was adressed when all the Cylinders werent firing (changed DIS) and it drove fine after.

The next issue was sputtering Back fireing and black smoke.

FPR took care of the black smoke. But my guy says you can drive it at minimal throttle, its wen u start to open it up that it stalls.

They say the best poker players know when to fold even when they have a hand with money in the pot.

Thanks Yall
 
Well guy I think that's the problem, this isn't a poker game everything is right there in front of you you just have to look and see. You never gave fuel pressure readings, nor have you really given anything for anyone to go on. You can't expect to get any real help unless you answer the questions asked. just saying "I checked" or "it's good" isn't enough. You haven't even given a good description, "It stalls" might mean something different to you than it does me. We can't see your car nor hear it, much less drive it, so you are our eyes and ears. Help us help you.

Ever heard the person that has "starter problems". The guy with the problem says "my car won't start", guy askes "does it crank?" The guy with the problem says "no it just turns turns and turns, I think I need a new starter".

Jeff
 
Well, we can't force ya to keep the car. If you're set on parting with it at this point then you should cut your losses and get it back from your mechanic to avoid any more parts replacement troubleshooting.
To be quite honest, and pardon the bluntness, but I think you're a damned fool for parting with the car after all the work and effort you've put into it. :( Regardless what car you own, there are going to be times when you're going to have trouble with it and it's going to give you headaches. But, in all honesty, it seems quite obvious the mechanic you have working on your car does not understand the intricacies of the Super Coupe and he is just swapping parts with the hopes he'll get lucky and find the part that's causing the trouble. I'm sorry, but that's not the way you repair cars. Trust me, I'm a mechanic and NYS Inspector. ;) Ask him if he's hooked up a fuel pressure guage and driven the car to check pressure at the rails. I'd be willing to bet he hasn't got a clue what you're talking about. Before giving up on this car, I would search out a knowledgeable technician that understands these cars and can accurately troubleshoot and diagnose your problem.
If you look at all the suggestions given so far as to possible causes, realistically there isn't anything mentioned so far that would be a staggering blow to a bank account. I understand you've put alot of time and effort into this car already, but at this point it seems senseless to give up on finding what's really wrong and admitting defeat. But again...it's your decision...
 
Back
Top