Pls help ASAP. Massive Misfire [Archive] - Forum


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07-05-2007, 12:57 PM
I've a 98 Montana van. It got a LIM gasket leakage and was repaired for about a month. Yesterday, I drove it out for about 20 miles and parked for 2 hours. When I fired it up and about to get home, something went wrong. The engine was shaking alot even my wife notice that. I just drove it home and it was getting worst. Finally, the SES light came up and flashing. I know it's not good.

Once I got home, I took my PT for a scan. It shown a massive misfire from cylinder 1. The misfire count just going up until 198 and start another cycle. There's no misfire counting from anyother cylinder. Also, it was missing coolant from the reserve tank. It's not alot but noticable. I fill it up last month after the gasket job done. And today I checked and it's only half left. I checked the engine oil every other day and I saw nothing on the dip stick. I also checked for vacuum leak but so far I didn't see anything wrong.

I'll pull the spark plug out and see what happened. What else I should look into? It's been running good until yesterday. It ruined all my plans for July 4, which sux. It's pretty much stock except I uploaded an OSID file to it. All I do is about tranny and some fan and coolant temp setting. It got reprogrammed from day one I bought it (Last Thanxgiving). Preivous owner did alot of work on it included replaced head.

I need to fix it fast cuz it's my family van. I don't want to use my Firebird to hual everyone including the dogs. PLEASE HELP :banghead :crying: :confused: :mad:

07-05-2007, 01:45 PM
Did you repair the LIM or did a shop? If a shop did it, I'd take it to them and ask them why the coolant is disappearing. If you did it, did you remember to put silicon on the ends of the valley? Also, how does your waterpump gasket area look? Look for any signs of leaking around the whole engine (I'm guessing you had the engine cleaned when the LIM was changed).

07-05-2007, 01:59 PM
Yeah, I did the LIM. And yeah, I did put RTV everywhere, basically I put a thin layer on both sides of the gasket. The waterpump and the gasket is basically new, about 3-4 months. And I really don't see coolant, except it was leaking in the rear bank.

The coolant disappear slowly. It's like, it was burned out or something.

Someone mentioned headgasket fail, except for this area (which I REALLY DON'T want to touch again) where/what should I look into?

07-05-2007, 02:00 PM
You need to isolate if it's a fuel or ignition problem. Can you take #1 plug wire off and verify you are getting spark? If so pull the plug out and switch it with another known good plug and see if the miss continues. If it still does then I would suspect that #1 fuel injector has either failed or you have lost compression in #1 cylinder.

07-05-2007, 03:09 PM
What should I do to check the injector?

07-05-2007, 03:27 PM
There is no simple way to check the injector itself. You would have to remove it and send it out to be checked.

07-05-2007, 03:55 PM
thats the exact symptoms i had with my blown head gasket and cracked head about two months back, it was even misfiring on the same cylinder, it was a blessing in disguise though cause i don't think i would of ever had my heads p&p'ed if that didn't happen, but ya its not a quick or cheap fix so good luck with everything

07-05-2007, 07:07 PM
Worse case scenario, if it has a cracked head, where can I get PnP head? Also, I search alot for good head gasket but I can only find Felpro, which I've a set here. Anyother head gasket recommendation? I don't mind put in more money but I don't want to keep fixing it in long run.

07-05-2007, 07:10 PM
PnP heads can be found at ben will take care of you, he is a great guy to deal with.

07-05-2007, 07:42 PM
I had my head p&p done through a local race shop, they did the works, re-cut , p&p, new springs and all that, but as alerored said that store will offer all the work themselves if they work on your engine, i cant remember what type of gaskets i got but i know the guy at the shop recommended them over some "cheaper" brand, by the way what engine does your van have?

07-05-2007, 08:23 PM
I've a machine shop can do the work too. I just dunno if the heads are ok or crack. I dunno think the crack is repairable tho. So if it's crack, I might go for 60degreev6 head.

The MLS loosk good. How many of you guys have it and how good they hold up?

I'm also thinking about L67 swap, if money is possible. Coz I figure, if I spend $1000-1500 for the head and other stuff, I might as well go for a swap if I can got a cheap 98-02 engine/tranny.

07-05-2007, 09:20 PM
see if the shop can test them for ya, the same shop that did my head work was able to do that for me

07-09-2007, 08:53 AM
does it blow any smoke at all?

sounds alot like my head gasket problem

but it depends on how quickly you're running through that coolant and if you're smoking even a little bit once it's warmed up

07-09-2007, 12:37 PM
It didn't blow any kinda smoke, no blue nor black. The coolant was dissapear slowly. The radiator is still fill (I just checked) and the reserve tank still has about half to 1/3. Also, I checked the dip stick and oil cap. No signs of coolant get into the engine.

I'll check the spark plug and wire today. Hopefully that's the problem. The previous owner changed to bosch wire already. Where's the fastest place to get a set of MSD or Taylor wire?

07-14-2007, 04:49 AM
Finally get it back on the road tonite. What a long day...I check the spark plug wire on cylinder 1, it was lose on the spark plug side and not locking at all. I was like "What the hell?" I pull the plug out but didn't pull the wire (freak stupid move :banghead ). The plug look good to me. So I install everything back and take a test drive with my PT. The wife did the driving and I read my laptop.

Drive it for 4 block and everything seems ok. After maybe 3-4 minutes, I saw 236 misfire on #1 :eek: and my wife yelled "SES light on now". What the ???? Check for DTC, same P300. The engine doesn't cholk at all. So I clear it and she keeps driving. Now the engine cholked a little and SES on again. I've to drive back home.

It's 7:30pm and I know something happened to the wire. That's why I'm soooo freaking stupid not pull the wire out the first time ;crap . So I ran down to Kragen and pick up a set of wire. Run back home and take every down. It ends up #1 wire was blown. It was exploded from the inside and crack the wire. The cord cover was melted. I've no idea how the hell that happen.

B4 I change out anything. I did a comprssion test on #1 and 6. #6 read 175 psi after 10 crank and #1 read between 165-170 psi. I'm kinda worry. After a big fight with the coil pack (mini van is REALLY a PITA :banghead :crazy: :crying: ), final take out all rear wire. So I put everything back and change the front bank. Drive it out at 1am (yeah mid nite) with my PT again. It seems like problem solve. I hit the freeway for 10 mins. I don't see any single misfire. But after I off freeway, I started to see a little misfire from #5 and 6 then 4 randomly. The longest misfire last 12 sec and count 7.

Any idea what it still misfire? It's new wire and the plug has less than 1000 miles on them. I used TR55 plug and Brog Warner wire from Kargen. Should I use some better plug and MSD wire. I think the voltage is not stable bcoz I blown 5 fuses on my HID within 2 weeks. Battery is about 2 years according to the label. And I guess the alterator is stock for 110k miles.

After reading at all the posts I was sooo worry about the rear head being crack. :(

07-16-2007, 06:34 PM
if it does not overheat at all i dont think the head is cracked. i would have the injector swapped (as they are more common than paris hilton and a dui) if that doesnt cure the problem just swap them back out and return the injector. the compression u got is perfectly fine. let me know if you havev any other questions

07-16-2007, 09:17 PM
Misfires happen on deceleration.. there's no need to worry about them.

07-17-2007, 07:08 PM
Drove it for a couple days with my open cone intake now. Everything seems fine, pulling strong and no overheat at all. I didn't have time to take another scan for misfire and I assume it ok.

It has some burnning coolant smell. And the reservsor coolant kinda disappeared, not much but noticable since I fill up on last Friday. There's no signs of coolant leak, I just smelled it burn. I also didn't find any signs of coolant in the engine. I've 195* t-stat with 3 drilled holes. Coolant temp gauge points at about 180*.

What should I look into this burnning coolant problem. It seems like didn't affect performance but kinda bothers me to refill the reservsor every two weeks.

07-20-2007, 07:53 AM
you say its not getting into the engine,,, so check the whole coolant system,, water pump and all....
leave it overnight somewhere clean and check the floor in the morning,, could be just leakin. i had coolant disappearing also On my old alero,, it was the water pump,, slooooooowwwly leaking....

and a week after your initial fill up,, its usually a bit low because the coolant gets in all the little places it didnt before,, closes all the little gaps\air bubbles.