Misfire on First Start-up
09-14-2012, 02:54 PM
#16
8th Gear
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Join Date: Apr 2011
Location: Geneva, IL
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Sharky - My coolant levels have remained constant, and I've noticed no coolant smell or white smoke at startup. I'm due for an oil change in 1k and I don't expect to see any intermix issues.
So, I cleaned the MAF as a preventative measure, changed the plugs and re-checked my coil connectors. The last 3 days there have been no misfire issues and no codes. Car has run smooth and powerful.
Cross your fingers, but I think it's solved.
So, I cleaned the MAF as a preventative measure, changed the plugs and re-checked my coil connectors. The last 3 days there have been no misfire issues and no codes. Car has run smooth and powerful.
Cross your fingers, but I think it's solved.
09-14-2012, 04:24 PM
#17
Race Director
Not so fast... The issues have resurfaced and I'm getting misfires on both sides now. I've replaced all six coils, replaced the plugs (which looked good to start with), and made sure that all the coils connected with a nice "click". The codes I'm getting right now are P0102, P1316, P1313, P1319 and P0306.
This only happens during cold starts.
I only have an OBD-II reader, so my diagnostics are limited to the reader and a multi-meter. I'm thinking I'll have to break down and take it to my independent.
This only happens during cold starts.
I only have an OBD-II reader, so my diagnostics are limited to the reader and a multi-meter. I'm thinking I'll have to break down and take it to my independent.
The errors are misfires, emissions related, which I take to mean are rich misfires. The risk from rich misfires is this dumps raw gas into the converters which can damage the converters. You do not want to damage them for they are expensive (>$1K/each parts cost alone) to replace.
If you insist on going ahead with self-diagnosis and realize there is a risk to the converters, and maybe the engine too, one thing you can try with your reader -- provided it supports OBD data viewing -- is to look at intake air temperature, coolant temperature at/shortly after cold engine start to see if either of these differ too much from each other or from what the ambient temperature is.
If you see a difference of opinion between the intake air temp and what you know ambient temp is you can suspect the MAF, which is also responsible for the intake air temp. The same applies to the coolant temperature sensor reading and ambient.
But I mentioned intake air temp first, because the P0102 is a MAF below limit which points to a MAF problem.
P0102 can arise from an open circuit, short circuit to ground, MAF faulty.
The wiring from the MAF to the DME must be checked for continuity, the wiring from the MAF to the DME must be checked for a short to ground, the signal from the MAF must be checked, and last but not least the engine air filter air box cleaned and the the filter element replaced.
The 1st 3 require some "special" tools and a good knowledge of these cars their wiring systems. The DME can be severely damaged -- read ruined -- if one is trying to test for continuity or a short in the wiring and he static discharges into the wiring that leads to the DME.
Sincerely,
Macster.
