93 SC Jerking & cutting out at boost

One diagnostic tool that can used here, is the "search" feature. A code
172Lack of oxygen sensor (HO2S-1) switches, indicates lean (BANK#1)
This is from the Ford factory training manual. Hook up your voltmeter to a O2 sensor signal line, and with a steady idle, and cruise, it should the DC voltage should cycle back between around .2-.85 vdc, with an average close to 4.6 vdc. Give it 60-85+% throttle, and the O2 volts should be .8-.9 vdc, and hang there. If it goes low, especially under .5 volts, the fuel is lean. Pump, screen, filter, or injectors.
For a coil pack, read this to the end. The HEI tester is usually all you need.

How to diagnose a faulty coil pack

I have been trying to troubleshoot a rich shuddering condition on my 92 supercoupe. After going through the process if eliminating several things it could be I suspected the coil pack could be the issue. I didn't have another extra unit laying around so I did some digging on how to bench test...
www.sccoa.com
 
too wide of a spark plug gap will cause bucking under a load also. I doubt it would throw those codes but just something to think about
 
Got the new ignition coil installed last night... That was definitely an improvement and now i get a better response once its warmed up.
I only took it for a short run.

If this is doesn't cure it I have some suspicions on the MAF, when unplugged there is no difference at idle.

This car hasn't been driven for 10+ years and I wouldn't doubt some other sensor issue causing problems.
 
I have a new method I'm working on to help guide those without professional experience, training, service information, and testing equipment. It works like the wheel of fortune. In the segments of the wheel, It will have the name of parts, like sensors, ignition, fuel system, components, etc. No testing, or knowledge required. You just spin the wheel, and when it stops, the pointer will tell you what part to replace.
 
SC-AL said:
One diagnostic tool that can used here, is the "search" feature. A code
172Lack of oxygen sensor (HO2S-1) switches, indicates lean (BANK#1)
This is from the Ford factory training manual. Hook up your voltmeter to a O2 sensor signal line, and with a steady idle, and cruise, it should the DC voltage should cycle back between around .2-.85 vdc, with an average close to 4.6 vdc. Give it 60-85+% throttle, and the O2 volts should be .8-.9 vdc, and hang there. If it goes low, especially under .5 volts, the fuel is lean. Pump, screen, filter, or injectors.
For a coil pack, read this to the end. The HEI tester is usually all you need.

How to diagnose a faulty coil pack

I have been trying to troubleshoot a rich shuddering condition on my 92 supercoupe. After going through the process if eliminating several things it could be I suspected the coil pack could be the issue. I didn't have another extra unit laying around so I did some digging on how to bench test...
www.sccoa.com
Click to expand...

The car is running pretty good now, got a few tanks of fresh fuel in it.

I am a genuine novice and much better with 2-strokes, so i will likely ask stupid questions.
You mentioned testing the O2 sensor voltage, How do you connect to the O2 signal line without interrupting it?

I am not getting a check engine light. But I do have a EECM reader, its a very basic interface. ill hook it up and see if that code 172 comes up.
 
I ran a self test with me Code reader and got 2 codes

118 : Engine Coolant temperature sensor above maximum voltage / 0 to-40 °F
157 : Mass Air Flow sensor fault, low voltage

More to come
 
E_train said:
I ran a self test with me Code reader and got 2 codes

118 : Engine Coolant temperature sensor above maximum voltage / 0 to-40 °F
157 : Mass Air Flow sensor fault, low voltage

More to come
Click to expand...
I have had the sensor unplugged recently. Anyone know if the code reader self test displays old codes or recent ones?
 
You need to clear those codes from memory. From your last post, I would say your injectors are dirty. I have done many professional level cleanings, on car, with great success. I think for now, I would run Chevron premium fuel, and add a bottle of techron, for every 12 gallons, or so. Some people have good luck with Seafoam, also. Make runs on the freeway/highway, and throttle it up, every now and then, especially under a load.
 
Looks like the KOEO self test ran fine.... no codes.
The KOER testing state a code 523

I grabbed some of the techron and added it to a fresh tank of premium

Ill have to see how she does
 
Started running some techron and fresh tanks of fuel. In my second round, and the bucking has really gotten better.

Seems unrelated but just recently the boost Guage is only like 12in.Hg. before it was >20.

Not sure
 
E_train said:
Started running some techron and fresh tanks of fuel. In my second round, and the bucking has really gotten better.

Seems unrelated but just recently the boost Guage is only like 12in.Hg. before it was >20.

Not sure
Click to expand...
Half way on my ride home it was running running pretty rough and then all of a sudden the Guage is reading normal. I swear there is a ghost in this thing or something.
 
E_train said:
Half way on my ride home it was running running pretty rough and then all of a sudden the Guage is reading normal. I swear there is a ghost in this thing or something.
Click to expand...
This really sounds like at least one if not multiple ground issues .
 
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