Rough Running

[DissT]

Ok so I have had an issue with the way the car runs and idles for almost a year but little to no time to really get into it.

I have changed the coil pack, plugs, wires and MAF. Checked for vac leaks in every imaginable way thinking this was the issue to no avail. Engine was rebuilt by KDK and ran great for about 50 miles and this issue came up, like I said it's been about a year. I dumped the fuel this time and put stabilizer in the tank and the fuel filter looked good and pressure is at 40.

Issue is idle and when you first get on it. It idles very rough and sometimes dies after a few minutes once it goes closed loop, starting is never a problem.

When you smash the go peddle it will stutter and spit until it seems to adjust itself out with boost. When in boost no isses and will break the ass end loose at 40mph, no knock with 850 readings. Cruising speeds with a little throttle blip will sometimes make it studder, sometimes not but always in the 200-400 range.

039-100 at idle and sometimes 000. If you bump the throttle it goes up to 828 and then back down to 100's.

af 05
L8 38-40
bat 13.6
int 128
bl 125
clt 175
ats 100
r 725 - 900
tps .46
iac 20
cc 228
nal 34

Thanks in advance for any help with this issue as the car will become my "driver" when home for the 4 weeks a year I am home

 

[DissT]

Nobody has any idea or suggestions? Should I do a compression check? Do you need more information? Anything?

 

[jimski]

Im no expert but how is fuel pressure, and are the fuel injectors good??The fuel injectors may be bad on a few cylinders

 

[DissT]

Im no expert but how is fuel pressure, and are the fuel injectors good??The fuel injectors may be bad on a few cylinders

Constant 40lbs on the guage and the injectors where cleaned when rebuild was done, might have to pull some out and take a peek. Does ethanol in the fuel affect injectors like it does on small carbs? I have had to send off both my dirt bike and my sons to have the carbs cleaned from being gummed up by ethanol.

 

[DissT]

Do the scanmaster numbers mean anything to anyone as to what is going on?

 

[whitecobra98]

the 34 is a malfunction code..check Turbo Regal Web Site for the proper code...it may be MAF..i'll check...it is..MAF signal LOW...replace with a known good one and drive it....the rest of the numbers look decent

 

[DissT]

the 34 is a malfunction code..check Turbo Regal Web Site for the proper code...it may be MAF..i'll check...it is..MAF signal LOW...replace with a known good one and drive it....the rest of the numbers look decent

That was the first thing I changed out, wonder if the wiring might be bad. I'll try to untape and retape the wiring. I also bought it from autozone and it is much smaller in the middle then the one I took off.

 

[whitecobra98]

That was the first thing I changed out, wonder if the wiring might be bad. I'll try to untape and retape the wiring. I also bought it from autozone and it is much smaller in the middle then the one I took off.

that could be the problem...i am NO expert when it comes to these cars as I am relatively new to the TR world, but most say AC Delco MAF's only...i can only tell you that the scanmaster trouble code relates to the MAF and the symptoms you describe make sense for it being bad...good luck

 

[DissT]

that could be the problem...i am NO expert when it comes to these cars as I am relatively new to the TR world, but most say AC Delco MAF's only...i can only tell you that the scanmaster trouble code relates to the MAF and the symptoms you describe make sense for it being bad...good luck

Put in the old MAF and reset the ecu and no more error code 34. Still runs a bit rough but is much better at idle sitting around 800-900 with no issues. Studdering problem is there only when you mash the peddle at low rpms, it's ok if you slowly press it to the floor.

Is it normal for readings to go from 800 down to 000 when you let off the pedal and coast?

 

[whitecobra98]

Put in the old MAF and reset the ecu and no more error code 34. Still runs a bit rough but is much better at idle sitting around 800-900 with no issues. Studdering problem is there only when you mash the peddle at low rpms, it's ok if you slowly press it to the floor.

Is it normal for readings to go from 800 down to 000 when you let off the pedal and coast?

they can read 000 when your foot is off the gas, as mine has several times..the problem I noticed is that mine was staying in the 100's and advancing slow..it exhibited some of the same symptoms as yours such as when trying to mash the throttle..02 sensor was going bad, but no code on the SM..make sure the counts are changing at a steady rate while driving, not holding for a while on one number