LS1 - 5 Dead Cylinders - Strange Issue
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LS1 - 5 Dead Cylinders - Strange Issue Hi everyone I have a heck of a problem. I have an LS1 in my off-road car being controlled by a MIFI computer. Car last year was completely required and I’ve put 1500 miles on it with zero issues. Last trip out it started running awful, first thing I thought was injectors as I’ve had a similar issue. I sent all the injectors out and they came back OK and I’ve used this company 3 other times. I have cylinders 3,4,5,6,8 all dead. I’m using an infrared on the exhaust and I know they are dead. So I swapped the coil, no change then the plug, no change then the wire, no change. I read about broken springs, I pulled the valve covers and BAM I found a broken spring and a loose rocker. I call an engine builder friend and he sends me out some new springs and I install them. I decided when I had the rockers off I would do a leak down, this would be the best time, all cylinders came back very good I was impressed. After I got new valve seals and springs installed I fired it back up and still no change. I have a Noid light and all the injectors are pulsing as should, I compared each one to a cylinder that is OK. I then bought an in-line spark tester, all cylinders appear to be ok, I tested that using a good running cylinder. The last thing I did was a compression test and they were all from 178 (lowest) to 192 (highest) with an average of 188 so I think that’s fine. I’m at a loss here, I can’t see it being a crank or cam sensor. I checked my big cannon plug in the motor and All pins OK, fuel pressure is at 61# like I said this car has 1500 miles with no issues so I can’t see it being a wiring issues considering I feel injection pulse and spark are present. Let me know what you think to check next, I’m going to use jumper cables to try as a ground to see if something odd is going on.
Dirt in Fuel Injector Filters Hi, I "prep" many Baja Race Cars finding MUCH dirt in the fuel system from Sand, Dirt OFTEN found in the "dump" cans.
FIRST, I would inspect the fuel filters, cut them open/replace the elements, inspect the elements.
I would have the fuel injector cleaned/flow tested.
Lance
FIRST, I would inspect the fuel filters, cut them open/replace the elements, inspect the elements.
I would have the fuel injector cleaned/flow tested.
Lance
You have spark, fuel and compression.. Sounds like it may be firing out of time on those cylinders.
To verify if it is or is not, find TDC on those cylinders and mark your crank pulley then shoot it with a timing light and see if it's close to the mark or a bit off.
To verify if it is or is not, find TDC on those cylinders and mark your crank pulley then shoot it with a timing light and see if it's close to the mark or a bit off.
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Well after all this my final hope was to verify the injectors were truly good so I swapped them around and we’ll guess what.... that was my issue, I’m beyond pissed at this point. That’s why you never trust someone’s word and I should have known this. I ordered 8 new injectors and will put them in this weekend and report back.
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My "tech", an injector ISSUE IS = NO THANKS Hi 503, WELL AS OFTEN, no good turn.
THUS MY TECH IS CORRECT !
Jacob (Pontiacolypse) ordered injectors FROM Pantera EFI (Lance) as of this day, at best price.
Would you be willing to STATE your cost ?
Lance
THUS MY TECH IS CORRECT !
Jacob (Pontiacolypse) ordered injectors FROM Pantera EFI (Lance) as of this day, at best price.
Would you be willing to STATE your cost ?
Lance
