99 Misfire, Help and input needed
Thread Starter
Joined: Dec 2013
Posts: 18
99 Misfire, Help and input needed
Okay so here's the story, recently my car wasn't starting so I got the starter changed and the day after I noticed a very bad misfire to where the car shakes like a stripper and sounds like a truck. I can't even drive a mile or over 60 without the SES light flashing. So I get a scanner and a few codes came up, 4 for Random Cylinder Misfire and 1 for the Crankshaft position sensor, then I decided to get the misfire situation fixed first. I buy all 6 ignition coils and spark plugs and when I go to install them, its still misfiring on the same cylinders. It looks like the connectors to the ignition coil are getting current to "power" the coils. I took the car to a mechanic to see what the problem is and he tells me "it look like it could be the ecu", although to me ecu's aren't a common maxima issue. So my question is, with all the information provided, does it sound like my ECU is bad? Or could it be something else? Any help or input is greatly appreciated, I've tried searching but my keywords weren't matching.
Member
Joined: Jun 2015
Posts: 249
Okay so here's the story, recently my car wasn't starting so I got the starter changed and the day after I noticed a very bad misfire to where the car shakes like a stripper and sounds like a truck. I can't even drive a mile or over 60 without the SES light flashing. So I get a scanner and a few codes came up, 4 for Random Cylinder Misfire and 1 for the Crankshaft position sensor, then I decided to get the misfire situation fixed first. I buy all 6 ignition coils and spark plugs and when I go to install them, its still misfiring on the same cylinders. It looks like the connectors to the ignition coil are getting current to "power" the coils. I took the car to a mechanic to see what the problem is and he tells me "it look like it could be the ecu", although to me ecu's aren't a common maxima issue. So my question is, with all the information provided, does it sound like my ECU is bad? Or could it be something else? Any help or input is greatly appreciated, I've tried searching but my keywords weren't matching.
Senior Member
Joined: Oct 2012
Posts: 2,974
From: Portland, Oregon
Question..... the starter was replaced, then your car missfired, all the plugs and coils repaced, and now the ecu?
Was all the work done by the mechanic?
Situations like this cause me to question the competence of this person.
A misfire can be isolated to one cylinder. Why replace all the coils? Original coils often outlast the after market ones.
Seems like your mechanic is using a shotgun approach. This is getting expensive quickly.
Consider finding another mechanic. Or learn how to do the work yourself.
Was all the work done by the mechanic?
Situations like this cause me to question the competence of this person.
A misfire can be isolated to one cylinder. Why replace all the coils? Original coils often outlast the after market ones.
Seems like your mechanic is using a shotgun approach. This is getting expensive quickly.
Consider finding another mechanic. Or learn how to do the work yourself.
Thread Starter
Joined: Dec 2013
Posts: 18
Did u change the crank sensor? Or even look at it? I just had same issue with random misfiring...look at my hard starting post...everybody on there had potential culprits of misfiring...I got great advice from everyone...also when u search make sure to click the Google search box
Thread Starter
Joined: Dec 2013
Posts: 18
Question..... the starter was replaced, then your car missfired, all the plugs and coils repaced, and now the ecu?
Was all the work done by the mechanic?
Situations like this cause me to question the competence of this person.
A misfire can be isolated to one cylinder. Why replace all the coils? Original coils often outlast the after market ones.
Seems like your mechanic is using a shotgun approach. This is getting expensive quickly.
Consider finding another mechanic. Or learn how to do the work yourself.
Was all the work done by the mechanic?
Situations like this cause me to question the competence of this person.
A misfire can be isolated to one cylinder. Why replace all the coils? Original coils often outlast the after market ones.
Seems like your mechanic is using a shotgun approach. This is getting expensive quickly.
Consider finding another mechanic. Or learn how to do the work yourself.
Member
Joined: Jun 2015
Posts: 249
I had the starter replaced by a mechanic then I noticed the misfire, then I decided to change the plugs and coils by myself. I bought the coils used, they're oem btw, and bought the plugs brand new. Once I noticed there wasn't a change when I changed the first cylinder I tested them while still connected to the connectors and found no spark. Then afterwards I took the car to another mechanic and he told me about the ecu.
Senior Member
Joined: Oct 2012
Posts: 2,974
From: Portland, Oregon
Yes, deal with the crank sensors. The computer makes decisions based on available information. Oily or corroded connections tell the computer a bunch of lies.
Thread Starter
Joined: Dec 2013
Posts: 18
Well quick update, i know its been a few days, but I finally got around to changing the crank sensors (both of them) and the cam sensor. I replaced them with used OEM sensors but nothing has really changed. Seems as though it just might be the ecu because the isn't any electricity flowing through the connectors on cylinder 1. The mechanic tested each connection right on front of me. Oh and also the injector on the same cylinder isn't working neither and he told me that its the computer causing all of this.
Junior Member
Joined: Oct 2015
Posts: 24
From: Williston, ND
I had the starter replaced by a mechanic then I noticed the misfire, then I decided to change the plugs and coils by myself. I bought the coils used, they're oem btw, and bought the plugs brand new. Once I noticed there wasn't a change when I changed the first cylinder I tested them while still connected to the connectors and found no spark. Then afterwards I took the car to another mechanic and he told me about the ecu.
Thread Starter
Joined: Dec 2013
Posts: 18
Hear yeee! he changed your starter now you have electrical problems?? The answer is quite simple he fried something during the install, and its funny he says the ecu cause thats bout the only thing that would fry haha idk if you trust him but i wouldnt. Also the crank sensor in the bellhousing reads your flywheel teeth to time ignition in essence, maybe he broke some teeth off or somethin who knows, all i know is if he wrenched on your car and now you have 4 misfires he fouled something up without a doubt
@ef9 I'm not too sure if its NATS related or not because my key doesn't have the chip in it like mostly all other 99s. Idk if that was done by the previous owner or it didn't have any to begin with
NATS just keeps the engine from starting. It will not interfere with an engine that is running.
But all 1999 models came with/have NATS. If your key doesn't have a chip in it, the previous owner must have done one of several things.
1) took the chip out of a key and taped it in the steering column by the NATS receiver. People did this to avoid the hassle of needing to pay over $100 if you needed a new key.
2) added a remote start system to the car. The NATS system had to be bypassed to do this and the chip from a key had to be put into the remote start system.
3) was swapping engines and didn't want to deal with all the pollution parts, so got an ECU from a 1995 and installed it. This also eliminated the NATS working.
But all 1999 models came with/have NATS. If your key doesn't have a chip in it, the previous owner must have done one of several things.
1) took the chip out of a key and taped it in the steering column by the NATS receiver. People did this to avoid the hassle of needing to pay over $100 if you needed a new key.
2) added a remote start system to the car. The NATS system had to be bypassed to do this and the chip from a key had to be put into the remote start system.
3) was swapping engines and didn't want to deal with all the pollution parts, so got an ECU from a 1995 and installed it. This also eliminated the NATS working.
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