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DISCUSSION => Engine + Driveline => Topic started by: RIPDOTCOM on December 13, 2007, 02:48:00 PM

Title: No Fuel On Cylinders 1 And 2
Post by: RIPDOTCOM on December 13, 2007, 02:48:00 PM

Last problem,, I think. I am definitely not getting fuel to cylinders 1 or 2. 3 and 4 are fine. Could a CPS or crank sensor affect this? Or is it more likely faled injectos, wiring or ECU?

Title: No Fuel On Cylinders 1 And 2
Post by: Abrax on December 13, 2007, 03:56:14 PM

I doubt crank sensor...

Check injectors voltage and pulses at first and than the injectors themselves..

Title: No Fuel On Cylinders 1 And 2
Post by: RIPDOTCOM on December 14, 2007, 07:06:00 AM

Swapped injectors 3&4 with 1&2 and same results (no pulse on 1 & 2 ) so they must not be getting voltage. I will pick up a noid light today to be 100% certain. I swapped ECU's from my other 91 that runs fine to no avail. I assume that 1&2 fire fuel at the same time and 3&4 fire fuel at the same time (correct me if I am wrong)  so the circuit must not be complete for 1 & 2. I understand that the Cam position sensor controls firing of fuel into the cylinders so I will swap that out as well today. Any other ideas would be great.

Title: No Fuel On Cylinders 1 And 2
Post by: Abrax on December 15, 2007, 03:16:07 PM

Your ideas are right ;)

And You are right, that M42 has semi-sequential fuel injection system... Fires injectors in pairs.

So If You are not getting any pulse on half of the injectors the ECU may be broken or wires may be broken.

I'm not sure if there are  any fuses for injectors themselves, but if there are no such fuses -> changing the ECU unit may point You the real reason for the absence of the pulse.