4G93 cam sensor, Cylinder misfire issues
#1
4G93 cam sensor, Cylinder misfire issues
Hi all, just wanted to get some input on a few issues I've been having. I'll give a bit of history.
I have a 4g93 head and cam, with all sensors, off a mirage motor. I've had random and infrequent cam sensor codes thrown, and tried to replace the sensor...but they don't work (bought from rockauto). Do 4g93 heads use different cam pos sensors depending on the year? The scrap yard I bought the head from didn't have a year for the mirage. If there are year ranges, I'll just have to buy several until I find one that works...
That being said, I haven't had a code in a while. I hard to park the car for 10 months, long story short, cam and crank seals had to be replaced.
I had driven it for 500 miles prior with only issue being a p300 cylinder misfire or random misfire code every now and again. I chalked this up to needing new plugs.
Well, after the mechanic did the seals, I got a cam sensor malfunction again. I cleared it, no issues. Then I started getting cylinder 3 misfire codes once a week. Then every day. SO I replaced all plugs with NGKs (was using bosch before, never again). It got WORSE. Random cylinder misfires at startup and at all RPM. So I replaced the OBX coils with stock, cleared it right up...
until I got cocky and did a WOT test, random cylinder misfire at 5500k. Okay, I cleared it, and have new plug wires coming just in case the rest of the OBX setup is ****e. That being said, now I'm getting random cylinder misfires about 3500k, regularly.
I'm wondering several things:
Did the jackhole who worked on my car screw up the timing?
Or is my cam position sensor finally crap and needing replacement (no codes throwing, though)?
Trying to get this resolved, as the car is NO FUN TO DRIVE atm.
Thank you for any and all help! I've searched and only found EVO issues related to the p300 codes, and no answers...and a bunch of additional issues introduced with a turbo. Or threads dating back to 2008, and I'd get flamed for reviving
I have a 501 MAF and it ran fine with that and ecuflash...no issues for years. No vacuum leaks, but I will recheck. New EGR last year, have a new IAC to put in but haven't yet...have pre-existing idle surge/drop issues that I'm trying to fix. Other than these, stock setup for engine.
I have a 4g93 head and cam, with all sensors, off a mirage motor. I've had random and infrequent cam sensor codes thrown, and tried to replace the sensor...but they don't work (bought from rockauto). Do 4g93 heads use different cam pos sensors depending on the year? The scrap yard I bought the head from didn't have a year for the mirage. If there are year ranges, I'll just have to buy several until I find one that works...
That being said, I haven't had a code in a while. I hard to park the car for 10 months, long story short, cam and crank seals had to be replaced.
I had driven it for 500 miles prior with only issue being a p300 cylinder misfire or random misfire code every now and again. I chalked this up to needing new plugs.
Well, after the mechanic did the seals, I got a cam sensor malfunction again. I cleared it, no issues. Then I started getting cylinder 3 misfire codes once a week. Then every day. SO I replaced all plugs with NGKs (was using bosch before, never again). It got WORSE. Random cylinder misfires at startup and at all RPM. So I replaced the OBX coils with stock, cleared it right up...
until I got cocky and did a WOT test, random cylinder misfire at 5500k. Okay, I cleared it, and have new plug wires coming just in case the rest of the OBX setup is ****e. That being said, now I'm getting random cylinder misfires about 3500k, regularly.
I'm wondering several things:
Did the jackhole who worked on my car screw up the timing?
Or is my cam position sensor finally crap and needing replacement (no codes throwing, though)?
Trying to get this resolved, as the car is NO FUN TO DRIVE atm.
Thank you for any and all help! I've searched and only found EVO issues related to the p300 codes, and no answers...and a bunch of additional issues introduced with a turbo. Or threads dating back to 2008, and I'd get flamed for reviving
I have a 501 MAF and it ran fine with that and ecuflash...no issues for years. No vacuum leaks, but I will recheck. New EGR last year, have a new IAC to put in but haven't yet...have pre-existing idle surge/drop issues that I'm trying to fix. Other than these, stock setup for engine.
Last edited by jwick76; Jan 16, 2014 at 06:26 PM.
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That mechanicx (Dec 19, 2022)
#4
That and I think the "valve job" I had on the head was bogus. I kept trying to tell the guy that if the head we got from the junk yard showed bent valves, to just junk it and I'll get a new reman. He was like "nah, we'll just replace the bent valves and reseat them...it'll be fine". I'm thinking the misfiring stressed the already craptastic parts too much, and one or several valves shattered.
It sounds like I have loose change rattling in the cylinder head, and it's running like garbage...most likely exhaust valves, as a lot of exhaust was still inside the valve cover when I popped the oil cap. I just parked it until my new mechanic can check it out. One thing that sucks about not having a garage of my own.
I found some reman 4G93 complete heads on ebay for $340, free shipping, with core return (prepaid). I just need new gaskets. Hopefully that's the only issue.
The pistons seem to be pretty strong...when my first head went on the highway at 70mph (timing belt snapped) they held up even with the valves slamming into them. I buffed out as much of the dings in the piston top as I could when we put the new head on.
But yeah, ovoid OBX coils at all costs. The boots are JUNK. MINIMAL insulation on them...just plastic tubes pretty much. ANd the rubber at the bottom tends to come off and get stuck at the bottom of the plug cylinder, so you can't get your plugs out without using one of those long spring-clip needlenose pliers. PITA.
Never again.
It sounds like I have loose change rattling in the cylinder head, and it's running like garbage...most likely exhaust valves, as a lot of exhaust was still inside the valve cover when I popped the oil cap. I just parked it until my new mechanic can check it out. One thing that sucks about not having a garage of my own.
I found some reman 4G93 complete heads on ebay for $340, free shipping, with core return (prepaid). I just need new gaskets. Hopefully that's the only issue.
The pistons seem to be pretty strong...when my first head went on the highway at 70mph (timing belt snapped) they held up even with the valves slamming into them. I buffed out as much of the dings in the piston top as I could when we put the new head on.
But yeah, ovoid OBX coils at all costs. The boots are JUNK. MINIMAL insulation on them...just plastic tubes pretty much. ANd the rubber at the bottom tends to come off and get stuck at the bottom of the plug cylinder, so you can't get your plugs out without using one of those long spring-clip needlenose pliers. PITA.
Never again.
Last edited by jwick76; Jan 20, 2014 at 07:46 AM. Reason: misspelling
#6
I had the same issue. I found out it was an aftermarket cam position sensor. The aftermarket sensor was giving offset timing reads. I installed an oem sensor and fixed the issue. I found this out with a timing light, the aftermarket sensor was jumping reads from dead on to 30% off timing. Hope this helps
#7
I had the same issue. I found out it was an aftermarket cam position sensor. The aftermarket sensor was giving offset timing reads. I installed an oem sensor and fixed the issue. I found this out with a timing light, the aftermarket sensor was jumping reads from dead on to 30% off timing. Hope this helps
yeah, those aftermarket ones are junk...had one from Rockauto not even start the car!
Got the head in yesterday, hopefully I'll be up and running by next week. *crosses fingers* The mechanic couldn't see anything wrong with the valves after pulling the head off...so I'm thinking busted spring...but definitely not trusting it for sure.
Lessons learned:
- Stay away from OBX coils and wires
- Stay away from BOSCH 4-platinum plugs
- When rebuilding a head, don't do a partial, DO THE WHOLE THING...don't let some idjit talk you into something else...I don't care what the compression test says. Used is used...unless it's from a car you owned and know how it was driven, you can assume someone didn't break it in correctly, never changed the oil, and drove it until it died.
- Never trust anyone to take care of your car when it's in storage...
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#8
Update:
Replacing the engine. Turns out the misfiring must have screwed one or two pistons. Probably slipped a ring. So, getting an engine with 80k less miles. Let's hope it's not coming from an R-tard that didn't change the oil *read typical female* lol
Replacing the engine. Turns out the misfiring must have screwed one or two pistons. Probably slipped a ring. So, getting an engine with 80k less miles. Let's hope it's not coming from an R-tard that didn't change the oil *read typical female* lol
#9
Back to stock 4g94:-/ I don't like it. The only good thing is that the idle isn't as rough, so the semi-solid motormounts don't shake my keys like a Salvation Army Santa bell.
Other than that, no pep. Going to focus on suspension, some seat lowering brackets, a little interior dressup, and some paint.
Probably sell it next year. Frustrating when you keep taking hits and can't get ahead on a project.
Other than that, no pep. Going to focus on suspension, some seat lowering brackets, a little interior dressup, and some paint.
Probably sell it next year. Frustrating when you keep taking hits and can't get ahead on a project.
#10
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I know the feeling, before I got my Lancer I had an 06 Impala, body and frame in beautiful condition, but stupid me never ran a carfax before I got it, had the head gaskets replaced(I didn't want to do it myself) and replaced the whole exhaust, cat all the way back. Then I noticed I had a little oil leak, when I checked the oil to see how much was leaking I discovered I had about 1/2 quart of gas blowby in the crankcase from the piston rings being shot. Turns out the motor had 157k on it BEFORE I got it.
#11
^ouch:-/
That's why I'm nervous. Not putting any more money into the motor, as who knows what any increase in HP will do.
Just going to clean it up, fix the major cosmetic issues (bumper, interior- new mats and detailing/shampoo, sunroof motor) and evaluate next year. If I can make it long enough with the current suspension, I'll do it...otherwise I might do the next owner a flavor and throw in a cheap set of used coilovers.
I wish I had a buddy that owned a paint shop! haha
That's why I'm nervous. Not putting any more money into the motor, as who knows what any increase in HP will do.
Just going to clean it up, fix the major cosmetic issues (bumper, interior- new mats and detailing/shampoo, sunroof motor) and evaluate next year. If I can make it long enough with the current suspension, I'll do it...otherwise I might do the next owner a flavor and throw in a cheap set of used coilovers.
I wish I had a buddy that owned a paint shop! haha
#12
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A nice discount on a new paint job would be nice lol. As far as my motor goes, I just got my lancer about a month ago and it only had a bit under 59k when I got it, and it's an 04 so i found a needle in the haystack. I know what you mean about adding HP, I see some folks wanting to boost the 4G94 block instead of doing a 4G63 swap. As far as I knew the 4G63 was already a boost ready block, where as the 4G94 is an n/a setup, I mean yeah, you can boost it, but what will be the potential side effects. I'm not one for doing something that may have the potential to grenade the motor of my dd, yeah the 4G94 may be a tad underpowered but I'd rather not deal with the potential consequences.
Last edited by RT78; Mar 27, 2014 at 01:44 PM.
#13
From what I've read on the forums you can do 7-8 pounds of boost on a stock 4g94 setup. Anything more than that needs heavy duty pistons, valves, and ported/polished head.
Way more money that I'll ever put into it. My goal now is to get it dressed up enough to sell and not feel bad about it. I won't sell a clunker or a lemon. A little dress up, a little mechanical solidity...and hopefully it's gone next year.
Way more money that I'll ever put into it. My goal now is to get it dressed up enough to sell and not feel bad about it. I won't sell a clunker or a lemon. A little dress up, a little mechanical solidity...and hopefully it's gone next year.
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#15
4g93
I have issues with 4G93 engine Galant 1997 model ,it misfires any solution ?
QUOTE=jwick76;11149131]Back to stock 4g94:-/ I don't like it. The only good thing is that the idle isn't as rough, so the semi-solid motormounts don't shake my keys like a Salvation Army Santa bell.
Other than that, no pep. Going to focus on suspension, some seat lowering brackets, a little interior dressup, and some paint.
Probably sell it next year. Frustrating when you keep taking hits and can't get ahead on a project.[/QUOTE]
QUOTE=jwick76;11149131]Back to stock 4g94:-/ I don't like it. The only good thing is that the idle isn't as rough, so the semi-solid motormounts don't shake my keys like a Salvation Army Santa bell.
Other than that, no pep. Going to focus on suspension, some seat lowering brackets, a little interior dressup, and some paint.
Probably sell it next year. Frustrating when you keep taking hits and can't get ahead on a project.[/QUOTE]
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