Running on 5 Cylinders, Help!

[mikes_ca]

Hey Everyone,

After a year of being down, I finally turned the key to start her up last week. Built bottom end, refreshed head with type B poncams, Haltech PnP ECU with MAP sensor, etc. Wouldn't run worth crap, but figured out there was an issue with the connection to the MAP sensor, and corrected timing.

Now it runs and idles, but only on 5 cylinders. Checked the coils, Splitfires, all but one had resistance of 1.3-1.5, cylinder 1 had 2.5. Replaced this with the best of my stock coils which read 1.2. Now I'm not sure what the resistance for the Splitfires should be, couldn't find that info. Still no luck.

Check the ignitor as per the manual, voltage at the connector going to the coils was 11.2-11.3 across all 6 wires, higher than the 9.5V the manual says they should be, but nothing out of line.

Checked spark plugs, and they all look the same, carboned up smelling like fuel (need a tune!).

I'm at a loss as to what to check next. Any ideas would be appreciated! Need to get this running so Vex can tune it for me.

Thanks,

Mike

[TW]

First, your best bet is to narrow down which cylinder is dropped. Unplug your coilpacks one by one, and listen for change. The one that doesnt make the engine drop ANOTHER cylinder is the one thats not firing. Thats a good place to start. seems strange that the plug would look the same though. Check to see if youre getting spark at the problem cylinder's plug, if you are then it's a fueling issue. in which case, you chould check the injector on that cylinder.

[GTS-James]

compression test dude, i took out an exhaust valve last year and was running on 5, oh and if u dont have the compression test tool go to canadian tire buy it, do the test and than return the tool lol thats what i did

[mikes_ca]

If it's an exhaust valve I better go buy a lotto ticket, the odds are slim. The head was decked, new oil seals, and checked thoroughly by D&W custom engines, and I don't think it has been damaged yet. But a compression test might be a good idea.

Checked the coils as per your suggestion TW, thanks. Cylinder 1 seemed to have the least effect on the engine, though there still was an effect, so hard to say which cylinder still. Swapped some coils around and it started running much better, idling around 1000 rpm, but still on 5 cylinders.

Using a timing light, it's showing a missing cylinder (not flashing constantly, missing one flash). Not sure what else to check.

Could it be a timing issue? Something off either so much or so little that one cylinder per revolution, not always the same, is not firing properly?

[GTRADDICT]

Plug gap? I'm saying this because you said cyl. 1 got more worst when you pulled the coil.

[mikes_ca]

Plugs are NGK iridium, heat range 7 I think, pre-gapped at 0.8. Shouldn't be plug gap since it's not seeing any boost yet. They all looked the same when I pulled them yesterday, carboned and smelling like fuel, which baffled me given not all cylinders are working.

[TW]

Thats odd..... youd definitely be able to isolate which cylinder wasnt firing by pulling the coils, if that was the problem. Maybe a timing issue then..

[GTRADDICT]

Meaby your plug is fouled (fawked) You wont see it but the inner core might be cracked... Try an other plug... Or take out the plug, attach it to the coil pack, ground it and crank. See if there's a spark.
Idiot proofing... you need a partner lol

[DBar]

I just fixed an issue like this on my car. what you should do is go get a set of copper ngk bkr7e plugs and gap them to your preference. Then when the motor is running try pushing in the plugs for the ignitor chip and moving them up and down to try to make up for a broken connection. My ignitor chip was the problem on my car. when i tested it it all looked ok cuz when i pressed down on the pins to probe it, it completed the connection inside the unit. When it was in the car the connection on the faulty pin was lost. Also an easy way to check your injectors to see if they are pulsing is take a 1/2 or 3/8 inch extention and gently press one end against the body of the injector and the other end to your ear while the car is running. if the injector is firing you should hear a smal click or ping like noise. If you can hear this then your injector is most likley working. the other thing you can do is check the ohms between the pins with a meter. your problem sounds just like mine and all i had to do was replace my ignitor chip.

[mikes_ca]

Thanks for the help guys. Still running on 5 cylinders and out of time after a major leak on my water pump. I'm sending the car to Vex in Red Deer for them to figure out and tune. I'll certainly recommend that they swap in a working ignitor to check if that's the issue.

Mike

[EtienneGignac]

Using a timing light, it's showing a missing cylinder (not flashing constantly, missing one flash).

How did you test cylinders 2 to 6? If your procedure is valid, you have your answer right there, inconsistent spark on that cylinder.