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Bad situation. Need help

1

1965Mustang

Member
To make an extremely long story short. I need someone to tell me who to talk to for help. I have posted several times and got a lot of help. Got my engine build finished in May. Ran great. Took it to Roush Racing for a tune. It is a 93, efi, 302 with several upgrades. Went to get it from Roush and the water hose had blown and torn up my brand new hood I just had painted. It can be fixed. Drove the car home and it would not start the next day. Finally found the adapter between the TPS and painless harness was missing. Fixed that. It would not idle consistently. Took it back to Roush. They said it was fixed. Went less than 1/2 mile and it was idling at 2500 rpm. Took it back. They were lost. Said to bring it back. Never did since I had no confidence in them. The head of the dyno room called someone else for advice. Took it to a friend who restores cars. He went back through all the wiring (Painless), changed IAC, changed to stock computer, and ran diagnostics. Never could get to idle consitently. Still between 1800 and 2500. Read the forums and found Pro Dyno in Rock Hill, SC to be one of the best. It has been there for 6 weeks now. Changed computers again, IAC, and TPS. Added FPA headers and Magnaflow 2 1/2 exhaust and retuned. Pulled over 300 rwhp, 330 torque and they told me to come and get it. I drove it around the block and it ran great. Was going to get gas across the street and it went crazy again. Then it woiuld not start until I bled the fuel rail. It is still there and they are lost. Only suggestion is to start changing parts which are all new. It is now grounded to the frame=twice, battery, and body twice so it is not the ground. It could be coincidence but I have not been able to drive it anywhere since I took it to Roush in May. Pro Dyno is supposed to be the best and they are baffled. Only way they could get it to idle correctly was to disconnect IAC. I need help. I am totally disgusted. If you need to talk, PM me and I will give you all my personal contact info. Thanks for any help. I am out of options.
 
Yes, but as I understand it the 93 OBD computers won't tell you a lot so I was told. Is this what you were talking about and is this correct? All the info it gave was about the IAC valve which was fixed. If I am being a dummy, please tell me. I am all new to efi. I need all the help I can get.
 
Start simple... sometime the clocking of the MAF sensor can impact how the engine runs... Loosen the clamps rotate the MAF a little..keep changing it to see if if makes any difference.

If you had to bleed the fuel rail, I wonder if your fuel pressure is too high. You might want to put a fuel pressure gauges on that port to monitor fuel pressure.

Also, What specific engine mods were done?
 
Post your questions over at www.sbftech.com There are some knowledgeable guys there. Pay close attention to a couple guys (Joel5.0 and Liljoe) they seem to really know those computers well and how to diagnose them. Tell them Bill sent you.

Bill
 
"67 Fastback" said:
Post your questions over at www.sbftech.com There are some knowledgeable guys there. Pay close attention to a couple guys (Joel5.0 and Liljoe) they seem to really know those computers well and how to diagnose them. Tell them Bill sent you.

Bill
Click to expand...

I appreciate the info and have registered on the site. Thanks
 
Is the car fixed. If so post the solution. If not I would think something is telling the computer what to fuel is bad. It be a simple as a ground wire for the sensor loose or just not making a good connection. Did you go through a idle setup procedure? When it's unplugged the engine should change VERY little. That kinda tells me the blade is not set correctly and this can be your problem. Sometimes the most simple thing is over looked.
 
The specific mods that drive the engine are: 1993 5.0 GT EFI HO roller engine
BBK Performance 8003 24# 75mm mass air
Comp 35-351-8 hydraulic roller cam-270 intake 276 exhaust-Lift .512/.512
Ford Powertrain Applications Custom long-tube ceramic header
Magnaflow 15815 stainless steel exhaust
Mallory MAL-11106M 110 GPH electric fuel pump
March Performance P560 100 amp, single wire, chrome alternator
MSD 31329 8.5mm Super Conductor spark plug wires
MSD 8227 high performance coil
MSD 8456 Pro-Billet distributor
Painless PRF-60510 wiring harness
ProDyno, Rockhill, SC, tuned-SCT6600 chip
Trickflow 51400510 1.6 roller rockers
TrickFlow 5182AITK cold air kit
TrickFlow 24575 75mm throttle body
TrickFlow 51500002 intake kit
TrickFlow 89024 24# injectors
Trickflow 51400004 Twisted Wedge 61 cc aluminum heads-170 cc intake
 
"1965Mustang" said:
The specific mods that drive the engine are: 1993 5.0 GT EFI HO roller engine
BBK Performance 8003 24# 75mm mass air
Comp 35-351-8 hydraulic roller cam-270 intake 276 exhaust-Lift .512/.512
Ford Powertrain Applications Custom long-tube ceramic header
Magnaflow 15815 stainless steel exhaust
Mallory MAL-11106M 110 GPH electric fuel pump
March Performance P560 100 amp, single wire, chrome alternator
MSD 31329 8.5mm Super Conductor spark plug wires
MSD 8227 high performance coil
MSD 8456 Pro-Billet distributor
Painless PRF-60510 wiring harness
ProDyno, Rockhill, SC, tuned-SCT6600 chip
Trickflow 51400510 1.6 roller rockers
TrickFlow 5182AITK cold air kit
TrickFlow 24575 75mm throttle body
TrickFlow 51500002 intake kit
TrickFlow 89024 24# injectors
Trickflow 51400004 Twisted Wedge 61 cc aluminum heads-170 cc intake
Click to expand...

I tried two new MSD 8456 distributors and I could not get the car to run well at all with either. The idle was terrible, power was non-existent and it would cut out. I tried a Mallory with no change. I have been running a 20 year old Ford Mustang distributor and all is good.
 
I was having a lot of strange things going on, and it turned out that on the '89 wiring harness, there's a ground for the computer chassis that I didn't connect. Hooked it up and the strangeness went away.
 
"kb3" said:
I tried two new MSD 8456 distributors and I could not get the car to run well at all with either. The idle was terrible, power was non-existent and it would cut out. I tried a Mallory with no change. I have been running a 20 year old Ford Mustang distributor and all is good.
Click to expand...
You are not the first to say that. That is what I was told when all of this started a few months ago but it checks fine. Spark is good every time it is checked
 
"66gt350" said:
I was having a lot of strange things going on, and it turned out that on the '89 wiring harness, there's a ground for the computer chassis that I didn't connect. Hooked it up and the strangeness went away.
Click to expand...
Actually that is why the last ground was run but that did not help.
 
Does it go nuts under the same conditions always or is it sporatic?

Do you have to bleed the fuel rail every time to get it back to normal?

Have you tried reclocking the MAF?

Have you checked the throttle blade? Is it sticking?
 
"1965Mustang" said:
You are not the first to say that. That is what I was told when all of this started a few months ago but it checks fine. Spark is good every time it is checked
Click to expand...

We had good spark, the car started and ran but could not get it to idle right and sounded off. On the road it had terrible manners. Hours of web research and under hood time led me to the distributor. May not be your problem but if you have a stock one to borrow may be worth the ten minute test to rule it out. Google that model....lots of problems out there.
 
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