Random Misfire plus other fun issuse

[99GSEclipsekamloops]

To start with my car is a 98 GS-T/X conversion with a 6 bolt 4g63 engine in it. As far as I know it is a stock turbo w/ a 1g BOV. I don't know if it is a wally 255 pump or not as I bought it used with a huge list of "mods" some really bad some decent. I don't think it has an aftermarket fuel pressure regulator. It doesn't have a wide band. I hope they are stock injectors. There is a turbo timer, and manual boost controller (set @ 10psi) and analog boost gauge installed. I don't have DSMlink yet as a timing belt issue burned a massive hole in my wallet...

Recently I had the timing belt snap, I think because the idiot before me put in the oil pan bolts wrong and it finally caught on one of them or something. Either way it went and bent all the valves and warped the head. Surprisingly no damage to the pistons. After I got that fixed I got stuck with that bogging down issue.

fml I have a laundry list of codes: P0300 Random misfire(duh), P0505 idle air control system, P1400 manifold differential pressure sensor circuit malfunction, P0450 evap. emissions system pressure sensor/switch, P0446 evap. emission system ventilation control circuit, P1105 fuel pressure solenoid malfunction.

I don't know where to start with fixing these issues, but the one that has been bugging the crap out of me is mainly the bogging down and it sounding like a subaru. I am fairly sure it is the ECU shutting off cylinders due to that infamous random misfire code after a 6 bolt swap.
Also the gas mileage is really REALLY bad. like 16mpg bad. I rarely drive it hard so i'm not sure why its so low. It also smells like gas when I really put my foot to the floor or right after I fill it up. The shop said it was because the gas tank vent hose is just going nowhere and the fumes are just leaking into the back of the car... I dunno about that, because they effed up my timing belt job 4 times... soooooo.....

 

[Black-Out]

Bro, if you're serious then you may have gotten the long end of the dick. the issue with this post is no one else knows where to start with helping you either- The car has been so extensively "modified" that very little is there to allow for the car to operate even remotely similar to what it should-

To start with, the fact that the car is a 98' with a 6 bolt swap opens up a gang load of issues with the wiring harness and that alone without anything else, can keep it from running like it should. I rarely have seen a proper 6 bolt swap done which will allow for the 98' computer to work flawlessly as it was intended from the manufacturer..... I have done a 6 bolt swap into a 98' GS-T and to do it right, (and by right I mean as the manufacturer would have done it) I literally stripped both engines down to the long blocks and transferred everything......and I do mean everything....over from the 7 bolt to the 6 bolt to make it work right. The wiring harness in it's entirety, the cams, cam shaft timing gears, cam sensor housing, crank sensor, crankshaft timing gear, water pipes, intake manifold, exhaust manifold, oil filter housing and sensors, coolant temp and sending unit sensors along with other sensors (knock sensor,tps, ect), Hell even the oil pan and all the emissions equipment I transferred over to the 6 bolt- all in the name of eliminating the check engine light headaches associated with doing a half assed job on the swap, so if anything did go wrong you could still hook up a scan tool and diagnose what the #### is wrong with the car-

Which "stock turbo" does it have? 1rst gen 14b? 2G T25 with the manifold? what about the injector size? you may not know but you must find out- you can't be up in the air about it- The fuel pump needs to be confirmed as well. What ecu is in the car? The 98' model? And then the fuel pressure regulator. If the car is running with the standard 98' ecu then the fuel pressure regulator is controlled by the ecu via a solenoid mounted to the bulk head on the drivers side - the vacuum signal gets cut when the car goes to W.O.T. and the computer senses it, causing fuel pressure to rise sharply to help supply the fuel for the demand under full load- aftermarket pressure regulators won't operate that way they must have constant manifold pressure. just one more thing to have to check on to make sure there isn't a discrepency, because if the car has the stock fuel pressure regulator and it's connected directly to the manifold it could cause fuel enrichment issues and the computer will code and the light will come on-

The fact that you have so many codes tells me the engine harness has been hacked and to that already puts you behind the 8 ball unless you have considerable experience with complex wiring repairs- just a heads up.

As for the belt breaking the bogging and misfiring is probably from a boost leak although a mis-timed engine, which can lead to bent valves, can cause this too. If they didn't do the job right then there is probably a good chance they may have just screwed up yet again.......boost leak check, Leak down, test compression check will tell you if its an air leak, or a mechanical issue-


You got a LOT of work to do brotha, I hope you didn't pay too much for the car because the last 6 bolt swapped GS-T I looked at for my friend here was cobbled together and it wasn't worth the money it was gonna take to un-#### the car.....He literally sold it and got another GS-T so he wouldn't have the headaches....


Good luck with it bro-

 

[redbud23]

Ok that is alot of things to go through without being, but the easiest way to do it is one fault at a time. Also they can all be created by one thing or many faults.

First, did you install the new timing belt correctly. I have seen several engines were the timing belt was off a tooth.

Second, take each piece or fault at a time. Start with the timing and check to make sure the belt on right.
Third, check your O2 sensor. Personally i would just replace them anyway they bad quite often. Make sure you have both of them and they are connected.
Fourth, check the sensors on your throttle body.
Fifth, look around the whole engine and look for any loose connectors
Sixth, when you got the car was it tuned or is it stock? It may have a dsmlink type eprom in it or others check to make sure.

Basically just check each sensor one at a time and you will find the fault.

 

[95DsManiac]

Like the two posts above it is a lot to tackle at once. Start with the ones that are less expensive and not as hard and work your way through it.

One easy thing I would check if I were is the firing order. Is it 4-1-2-3 or 3-2-1-4. I ask this because when doing the 6 bolt swap and using the 1g cas you would have to invert the signal and change the firing order. I thought it was one or the other when I switched to a 1g cas on my 7 bolt but I had to do both to get it to even start. Try to find the firing order and post it.

If it has a 255 and no regulator then that may be a problem as well with bogging and drivability. Is there a loud humming noise under the rear seat? If you can't notice one I would just pull it out and check for part numbers. It is a nice thing to know what exactly you have in your car at all times. You can never go off what someone else is saying especially when they didn't even take the time to mod the car the prop way it which any Dsm shall deserve.

Overall I wish you luck mymdriend on your journey/struggle with your Dsm. And trust and believe it will be a journey and a struggle for it is always something . Jk, but yu know what I mean. Good luck, measure twice cut once and overall have fun with it. Take it as a learning experience and learn everything about the car so you get an understanding for what everything does and how it operates.

Anthony B.

 

[99GSEclipsekamloops]

Thanks for the replies guys... Well when I was getting the codes from the ecu I actually cleared them again (second time) oddly enough the bogging down cylinder shut off completely went away. I've driven about 100 miles so far and not one problem... So strange. I mean the cel is still on but WTF ever
I hope this isn't too noobish, but how do I tell what size the injectors are? The fuel pump was changed just before I got it. Found the factory one in the glove box . I'll try and pull the pump to find out what it is... i have to anyway as the Derp monkey bent the float so it never reads above 1/4 tank (awesome right?)

As far as I know it is a 98 ecu (flashable?) I know most of the bits are 1g but I doubt its a 1g turbo its probably the 2g one. Looking in the engine bay makes me want to slap the shit out ofwho put it in there.... Hoses not connected, plugs not plugged in, oh its a regular shit show.

The only saving grace is I bought it for $2k with 98k miles on it and now only 1000 miles on the engine.

I'll have a good look in the engine bay and report back.

 

[99GSEclipsekamloops]

So now I have fixed most of the issues causing codes... the only one left that I haven't cleared yet is the IAC code. It might be a faulty sensor, but I don't want to just start replacing stuff if it isn't broken. The idle is a little weird after driving in city I.E. stop start stop start the idle goes down to 700 were it is supposed to be, but if I come off the highway the idle is at 1700-2000 and stays there until I drive a bit more in city.... any idea what this might be other that a busted IAC....
Thanks guys!
P.S. I've flashed my ECU to get rid of the pesky P0300 code so thats awesome!!