Intermittent misfire
- Thread starter Suprasonic19
- Start date
thats a good question...do you have pics of the tear? you will most likely have to find a better one and replace it...im sure there are enough part outs going on right now that someone will have an extra......
Well what looked like a small crack became a large tear once the pipe was off. So it looks like I am going to be trying to track down a new pipe. Also I noticed the small vacuum hose that connects to the bottom of this pipe and goes down to the block was very weak and might have been disconnected. So Ill replace that too.
And here is an idea of how much oil got into the galleries.
And here is an idea of how much oil got into the galleries.
Hey you weren't joking. Ill pick one of those up. Thanks!
http://store.driftmotion.com/static/i-7m-gtestockaccordianintakehose.php
http://store.driftmotion.com/static/i-7m-gtestockaccordianintakehose.php
Just called toyota and the #3 valve cover gasket is $60 and the accordion pipe is $62. I can have both first thing in the morning. Once I get them Ill torque the cover to spec and hope that stops the leak.
Suprasonic19;1670594 said:
That's EXACTLY what mine was doing. Everything you described in your OP as well. Under load was ok. Anything else and any rpm, misses. I did the jetjock ignitor ground mod and that helped a LITTLE bit, but it didn't totally cure it, and the engine was suffering from an apparent BHG soon after that so I have not had the chance to track it down further. It's now at the machine shop for a second rebuild.
I have heard that a weak fuel pump/slightly low fuel pressure can cause a miss without throwing a code so that might be something to check. Have you noticed it to miss more when the fuel tank is less than half full? Mine would ALMOST run perfect when the tank was topped off and slowly degenerate to nearly un-liveable by the time it was down to a quarter tank. Yours may or may not act the same...
It did act like that until I put a fresh tank of gas in it. But if the problem persist after I install these new parts I will definitely check that.
I have several ECUs currently with different levels of modification to them that I swap around routinely. The stock ECU, (p/n 89661-14271 1990 A/T), idles perfectly. When I swap in an 89661-14270 (1989 A/T) I get the miss shown in the two videos. Depending on what I do to the guts of the ECU I can make it worse, alot worse in fact to the point the car is essentially undriveable.
I'm still not sure where it is coming from, but suspect it is a noise issue within the ECU on the G1/G2 signals. I have some ideas I am running through to get to the bottom of this. If I make any progress on debugging this I'll post up here.
I'm still not sure where it is coming from, but suspect it is a noise issue within the ECU on the G1/G2 signals. I have some ideas I am running through to get to the bottom of this. If I make any progress on debugging this I'll post up here.
thats really cool 3p....i have the exact same miss in mine with both of my computers...i have the 89 cali ecu and then swapped to the JDM ecu when i removed my egr system....miss was the same with both......i think ive actually got a few really small issues adding to a minor miss...fortunatly im not as bad off as either one of these guys but a miss is a miss and not good....
Just an update: I put on the new accordion pipe, replaced the small vacuum line coming from the bottom of it towards the block, cleaned my plug wires and plugs, and replaced the 3rd valve cover gasket this morning(also found a tear in the little vacuum hose coming of the top of the bov so I replaced that line too.)and it was running fine under it got completely warmed up...then it started missing again. Just as bad as before. SO I said screw it I gotta drive to work anyways. Well, once I got out on the road the miss went away, completely. At every stop light and cruise down the highway, coasting, all the usually spots where it would show up it didn't. The car was running smooth as could be. Boost was strong and consistent too. Well I drove open highway 30 minutes to work. The car sat for roughly an hour, and then when I went to start it it started then died. So I started it again put popped the gas once. Every since then its been running 90% better and Ive been driving it alot today. It still misses only at idle now. And its not as often, say one miss every 30 seconds if your in drive at a light. But misses every couple seconds if you are in park or neutral. I also got it smogged today and it passed. All the levels were low and good. So now I can take my time and track down this thing, I just don't know where to go from here. I suppose Ill go over more wiring and vacuum hoses.
boostcraver;1671492 said:
Because you are lean. Which is why the car starts ok for many people, then runs bad when warmed up. Cold start strategy can request nearly double the fuel volume on each pulse. Notice how the cracked intake piping cleared up a bunch of his driving problems?
---------- Post added at 08:16 AM ---------- Previous post was at 08:12 AM ----------
3p141592654;1671805 said:
You think you are getting RFI on it?
Nick M-Would a bad/weak fuel pump cause an intermittent miss? Will run fine at one stoplight but miss constantly at the next light?
Well Ive driven roughly 400 miles in the past 3 days and I can say the misfire is not only back, but worse. The car stalls when I put it in gear(automatic) about 3 out of 5 times unless I just barely touch the gas while shifting. It actually stalled while I was just turning around once. I pulled a plug wire and the plug galleries are full of oil again. So tomorrow Ill remove the valve covers and try to reseal them again and clean the galleries. While I'm there Ill try and look for more vacuum leaks. Also noted that under heavy acceleration the engine stumbles around 3500 only in second and third gear for a couple seconds then keeps revving until it shifts. Boost stays at 7psi during the stumbling, but then after the stumbling stops and it continues to rev I hear a metallic noise from the engine until it shifts. The noise isn't always there but Ill try and get a video of it tomorrow.
boostcraver;1673227 said:
Thanks for repeating what I just said.
I went to ebay to pull some adds for scopes. One is fancy that I didn't use at Toyota because most 1MZFE Camrys run hitch free a long time. The Fluke 95 I used often for other things.
http://cgi.ebay.com/ws/eBayISAPI.dl...akeTrack=true&ssPageName=VIP:watchlink:top:en
This next one is the fancy one, and not worth your money. You would need to be in business for yourself, unless you like spending large amounts of money on tools you hardly use.
http://cgi.ebay.com/ebaymotors/Bosc...Z130481827865QQptZMotorsQ5fAutomotiveQ5fTools
UPS man just delivered Driftmotion's little present. New valve cover seals, rubber washers, replacement cover bolts, and a new CPS cover gasket and bolts. Oh and a tube of FIPG, or "The Shit".
So tonight I will go back through and repair the oil leaking into the plug valleys problem, clean the plugs and recheck the gap and for any cracks or problems. Thoroughly clean and dry the plug wires and look for any problems with them, and recheck the seals on all my intake piping. And replace the CPS cover and inspect it for any wear or problems.
So tonight I will go back through and repair the oil leaking into the plug valleys problem, clean the plugs and recheck the gap and for any cracks or problems. Thoroughly clean and dry the plug wires and look for any problems with them, and recheck the seals on all my intake piping. And replace the CPS cover and inspect it for any wear or problems.
Im positive my intake gaskets are good. Not only are they less than 2 months old but Ive sprayed throttle body cleaner all around them with the engine idling to make sure there were no leaks at all.
Well today I installed all the new parts and double and triple checked everything I could see and touch. Ended up making a new ground wire for the coilpacks cause mine was getting a little frail. After over looking everything the only questionable thing I could find was a hairline crack in one of the plugs. I mean absolutely barley visible. I only found it after looking through a lighted magnifying glass. But I still replaced it and another plug that I thought could have had a crack also. I also found a crack in the vent pipe that goes from the intake side valve cover down to the lower timing cover. I see Driftmotion has on so Ill replace that asap. Not sure if that hose would cause a miss but none the less it needs to be replaced.
Topped off the oil and started it up. All was good till the temp gauge got about 5 dashes of the bottom then it started to come back. Much much better than ever before, but its still there. So I drove the car around for awhile then picked up some b12 Chemtool fuel system cleaner and put that in the tank since I was at a 1/4 of a tank anyways, and went and got some fresh gas. So Ill drive around tomorrow for awhile and get that through the system.
Im thinking this miss is fuel related...any imput?
Topped off the oil and started it up. All was good till the temp gauge got about 5 dashes of the bottom then it started to come back. Much much better than ever before, but its still there. So I drove the car around for awhile then picked up some b12 Chemtool fuel system cleaner and put that in the tank since I was at a 1/4 of a tank anyways, and went and got some fresh gas. So Ill drive around tomorrow for awhile and get that through the system.
Im thinking this miss is fuel related...any imput?