Hard starting & stalling issues
 

I'm having some hard starting/stalling issues. I cant get this thing to keep running without constantly blipping the throttle from the engine compt. It's newly rebuilt street-port ( intake and exhaust) with 100 psi on each housing compression test. Lightweight flywheel but stock disc and pressure-plate. Downpipe and midpipe with high flow cat. No catback yet!! {Open exhaust after mid pipe as of right now}Aftermarket Fuel pressure reg. and dampner elimination mod. 3 bar MAP and Simplified seq mod. Iridium plugs and Magnecore wires. All hoses zip tied with silicone hose and aftermarket turbo solenoid. All this on stock ECU. Keeping stock seq. turbos and pressure.

What could be causing this problem. I have to hold the wires off the edge of the plugs to get it started and then constantly tap the throttle cable for it to keep running. Soon as I stop, she dies!?! She doesnt backfire and I can almost stop tapping the cable. It's like she wants to idle but something isn't working right!!!

HELP!!!! HELP!!!!HELP!!! PLEASE!!!!!!!!!!!!!!!!!!!!

Should I have increased my fuel pressure since I did the street port? I'm running the stock 38lbs.?

Who did the install? Who built the motor?

The questions is what apex seals was use in the motor. Usually it take awhile for the motor to break in so let the motor run and turn the idle up alittle form idle to be stable.

I did the rebuild myself. I got all the parts from places like racing beat(the port templates), Mazdatrix (the gaskets), Atkins Rotary (the seals). Followed the video for the rebuild which isn't really that difficult. I replaced a few housings. Namely the center intermediate ( there was a broken piece inside of it) and the two rotor housings because they were scared and scuffed up beyond what I was comfortable with. Plus I got a deal on a pair that were already ported. When I did the compression test, I was very happy with the numbers I got. 100 psi from each side. Doesn't that mean All is well with the rebuild?

Have you changed the primary injectors??

I actually had the same problem of sorts i only had 60 miles on a new street port and i couldn't for the life of me figure it out. It ended up being the alternator not being fully functional and when it was about to die it was dumping insane amounts of fuel in so we cleaned the brushes in the alternator and everything is good now. I had KDR look it over because everything i came up with was just fine. Not too sure if it'll be the same problem for you but it might be one thing to check out.

I actually just had the alt rebuilt. I doubt that it's the prob but I will have it rechecked. Thks. As for the injectors, No i havent changed them. Didn't think i had to. Im keeping the stock ecu and boost pressure, so I figured that they were more than adequate. I'm leaning more towards either an idle adjustment issue due to porting, fuel pressure adj due to porting, or a bad sensor. ISC or TPS. They're the only sensors I have connected. Along with the IAT under the UIM. I also did the fuel pump mod for the full 12vlts. This is really driving me crazy. I had my son start the car and since I put the MSD on the leadings yesterday, she starts up quite a bit easier but I just can't keep her running without constantly tapping the throttle cable. I took the elbow off and watched the primary butterfly and it barely moves which is why I'm thinking TPS.

might be way off,but....can the ecu be going on limp mode?

As Wo Deep already asked, are you running freshly cleaned fuel injectors? the cleaning solution can solidify if they sit for too long before install and the car won't run b/c the injectors aren't at full capacity.

I finally did the TPS adj procedure to verify the in-range voltages and I can't seem to get them both within spec. I can get the top wire, 3F, into range but the bottom, 3G, is off a bit. Does that mean the unit is shot; or is one more crucial than the other?

How do you tell if its in limp mode? if so how to reset?

I didn't send the injectors out to be cleaned or anything like that. I quess that could be the problem. I did run a siginificant amount of fuel system cleaner through. I'll have to make note of that and check it out.

Try it with the stock map sensor, not the 3bar.

I was just thinking that! I think it was bad but I can definitely give it a shot. Still curious about this TPS. Which if any is more important? 3F or 3G.

i dont think you can run the stock ecu with a 3 bar map sensor. not correctly anyways.

all the scales would be off and it would put the wrong amount of fuel in. it's still a 5 volt sensor but the voltages mean a different amount of air, the ecu has to be programmed to offset this difference. you either need an aftermarket ecu or a stock map sensor.

also as far as your tps, the primary butterflly may need to be adjusted in order to get the tps in the correct range. its actually the main idle adjustment screw (not to be confused with the idle bleed screw) but it also effects the tps.

Wow, i didn't know that! well hopefully i can find my OE MAp sensor. That might be the whole problem cause everything else seem to be fine. No vaccum or coolant leaks plugs are firing etc. Thanks! i'll give that a try!

I was under the impresion that the primary butterfly had to be completely closed. Not held open by anythingat all, so I backed off the set screw atop the TB, and I backed off the Throttle cable. I also set a phillips screwdriver it the fast idle cam to make sure the butterfly was absolutely clear. I still, even at each extreme couldnt get the TPS in range for the bottom wire.

the primary butterfly is the idle adjustment, so if its completely closed the car may not idle high enough. there is also an air bleed screw which is on the lower right corner of the throttle body if looking straight at the butterflies with the throttle body elbow removed. this screw should be set half a turn out. its for fine tuning the idle, after about 4 turns out it doesnt do anything cause its fully opened. But the main idle adjustment is on the top of the throttle body and adjusts the primary butterfly.

here are a few pics i have saved.

http://i10.photobucket.com/albums/a1...emaaan/tps.jpg
http://i10.photobucket.com/albums/a1...aaan/TBadj.jpg
http://i10.photobucket.com/albums/a1...emaaan/tb6.jpg

Thanks a ton for the pics. Those are exactly the items ive been teasing. I found my oE map sensor but haven't noticed much difference at all. I probably need to reset all the adjustments back to factory. I know the air bleed adj but the other ones like the Throttle cable, the primary butterfly adj and the fast idle cam behind the TB. Anybody know those?

The thing is though, the TPS. Like I said before, I went to both extremes but can't get the bottom wire in range. I even took the TB completely off and backed out all the adj.s Think I need a new one?

you didnt take the tps apart did u? if so its easy to get it in there wrong. the throttle cable should be adjusted so its tight but puts no additional pressure on the throttle. i removed my fast idle cam as it some how made my throttle stick open a few times. i think u can wire it out of the way while you are setting things up. otherwise its easy enough to remove it.

its possible the tps is bad, im sure its happened to someone somewhere. did you check the stock map sensor to make sure its in spec? you will need to apply vacuum to test it properly

no, I didn't check the Stock MAP but I'm not getting a CEL yet either. I didn't take the TPS apart, I just took the TB off to better reach the wires and make sure that nothing was stopping the butterfliy from being completely closed. But whats confusing me is that the butterfly shouldn't be completely closed because it controls the idle; so should that range on the TPS actually be taken "AFTER" the butterfly is open to it's factory setting?

There is an air bleed hole that the car idles off. You can have the plates completely closed and it should still idle. My shop is in central jersey if you want to bring the car by.