6 Replies
Yes, it could be the PCM but you need to be sure a s to what isn't happening for cyl's 4 & 6 first. Make sure you're gettiing spark from the coils. if so, check the injector circuits for power and ground. This injection system is ground side controlled, you should have 12 volts on one terminal and no ground until the engine is cranked or is running, then you should see ground as a signal to fire the injectors. I've seen problems in the ground side of these vehicles causing an injector to fail to operate.
yes but first u need to check for vaccum leak at the pcv hose and the upper to lower intake gasket . these cars are bad about that .
Ditto that. We see alot of the lower Intake manifold gaskets leaking on these. They are just Oring gaskets and they get hard over time
sorry my answer which follows is wrong..but thought i would share my issue....Same issues a lot of you are having the misfire was caused due to leaking valve cover gasket.. the coil paks go down thru the center of valve cover and the seal to keep out the oil was bad so oil leak down into the tube where the spark plugs are and the spark from the coil didn't make to the spark plug (grounding to the block) thus causing the misfire..if you take out the coil pak and see that their is oil on the rubber tubing you have a valve cover leak..hope this helps someone..
I would like to thank one member for admitting stupity. recently changed coil packs and sparkplugs in 2001 mazda tribute, upon restart had bad misfire .went back and switched coil packs and plugs around could not find issue . took in for code ck there were no codes other then a o2 sensor. have been reading all comments here checked wire harness all vacume lines everything I saw here, then saw one I had previously kinda ingored switching coil wires between 4 and 6 . omg was I happy alls well now just a thought some times stupity may be hard to admit but you never know how helpful it can be TYVM
Just want to say thanks to the member that told us about switching coil wires 4 and 6 it fixed our 01 Ford Escape
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I have verified three different ways that the coils are getting power from the PCM. 1. Pulling the coil and hooking it to a spark plug tester I see a good spark. 2. I hooked up a noid (used to test fuel injectors) to each coil pack wire for 4 and 6 and with engine running the noid was flashing. 3. With the engine running I pulled the connector for cylinder 4 and got code P0354 (Ignition coil D primary or secondary circuit malfunction). If I pulled the connector for cylinder 6 I got code P0356 (Ignition coil F ...). Also, if I pull the connector for 4 or 6 I do not notice a change in engine sound or idle quality. However, if I pull 5 (a good cylinder) it is very noticeable. I have also verified the fuel injectors are getting power using the noids. I have checked engine vacuum at the manifold and it is 18 in Hg at idle. Fuel pressure at the schrader valve near the injectors is 53 PSI.