My motor is in, and I have had a lot of problems getting the car to run, let alone even idle.

I had the motor rebuilt with a 2nd stage street port, cryo'd the rotor housings and all the seals, and the injectors have been cleaned and flow tested. The ECU is stock, as is everything else. Heres the problem. When the motor went in, I had a walbro pump installed. It flowed so much fuel that the motor would just stall itself out. It had to be held above 1k rpm to run. Wouldnt the pump be fine with the stock management? It shot 4 ft. flames and ran way way way too rich surprisingly, didnt burn the bumper. At any rate, I decided to revert back to the stock pump and it helped a bit with the idle, although not much, as it would still want to stall out. On start up, my mechanic managed to have so much extra fuel left over in the exhaust, that when he started it, a flame shot up and burned all the way up to my reverse light and past it, not to mention a deep burn mark the size of a basketbal nearly melting the bumper nearly all the way through right above the exhaust. This flame on the stock fuel pump and injectors?

So here I am, with the cars idle set at 1500-1700 via throttle cable adjustment, otherwise it stalls, and it runs really really rough. I know there are arguments of whether or not to run the car hard or baby it when its breaking itself in, but at any rate, since its running so poorly I figured to stay below 4k to be safe. It clears up a tiny bit from 3-4, but its still rough. Feels like it sputters or has severe hesitation throughout the RPM range of 1500 on up to 4000. Why is it running so rough? Is it because its cryo'd and the rotor housings are harder, and the seals are taking time to seat so I am getting low compression? Is it a fuel issue? Stock pump, stock injectors, yet its still running rich as ever. Or is it a vacuum leak? I had my vacuum lines checked, my air pump, and my egr valve, and trusting my mechs word, he says everything is fine with no leaks. He just sprayed carb cleaner on the vacuum lines and looked for leaks. I dont think thats a sure fire way of figuring there are no leaks. Thats how he said he tested the lines. So, what is the deal here? Should I try to break it in? Is it usually this rough during break in? Im worried that if I drive it any longer, I may end up doing way more than "breaking it in"....I feel like Im gonna flat out just break the motor entirely. I put about 20 bucks worth of gas in, at 2.30 per gallon, and got about 25 miles before I was on Empty again.

In all of a basic request, I just want to know how a rebuilt motor is supposed to run, fresh off the bat. Is it really this rough, with a streetport, cryo, and STOCK fuel management, injectors, and pump?

Knowledgable suggestions are greatly appreciated, as I would love to get this thing running right, granted all the money, time and drama that I have gone through to get to where I am.

 

well, i just got a rebuild with i/h porting and 3mm's. it seems to run like normal even though i cant boost yet or rev high, oil pressure is way up there and it seems to be really working the starter more when i cold start it which could be alot of simple things. stock ecu and stock fuel, intake/dp/cb.

 

I think when you rebuilt your enines with Streetporting you must change the timing for ignition and fuel . Diffrent open and closed Timing and it wouldn´t work with stock ECU . I think and sorry for my bad english. ....good luck

 

you cannot run a street ported motor on the stock ECU



the timing is completely different, you're running wayyy too advanced timing for that port job, you need it to be retarded

my advice:

park the car, check your map sensor (sounds like you're having issues with it), get a standalone

btw, are they new rotor housings?

 

ok, from what my rebuilder told me, I can actually run my stock ECU with the motor how it is. I have no cash for a standalone unit, since I just blew 7g's on this rebuild. But ya. I do need to get a power FC or something like that real soon, but if I get that and it doesnt fix my problem, I really wont know what to do. where is my map sensor, and what should I look for? Im sorry Im asking such a newbie question like that, but I really really need to learn more about my motor, and having you guys helping me out is huge. They are new rotor housings btw. So it may not be vacuum related eh? Just a timing issue? is there some other way of fixing both my fuel and ignition timing without getting standalone? a.k.a. Temporary fixes, just to break in the motor? One more thing I forgot to ask earlier, is that if the motor does break itself in properly, will the aftermarket fuel pump that I have now still be necessary, due to how rich Im running NE wayz? I got one just in case, and like I was sayin', it turned out to be far too much. Someone correct my dumb ***, or as blackFD did, gimme a good slap, cuz I need some serious sense knocked into me.

 

i doubt it's your ecu, unless you have some type of race port. i ran my streetport from pettit with a stock ecu for a few thousand miles-ran fine.

 

I don't think you have a problem with the rebuild or the timing. Your problem stems from too much fuel. If anything, a streetport would require *more* fuel, not less.

I've read that you can run a mild street port on a stock ECU. Regardless, even if you did need an ECU to run richer and safer, you should be able to get it run reasonably well on the stock ECU.

You also started to blame the aftermarket fuel pump, but said when you switched back to the stock one, it didn't fix the problem... so the aftermarket pump is not a problem.

As far as I know, the timing is not adjustable with a stock ECU.

You need to fix the fuel issue, and I think all of your other problems will be gone. You may just have a stuck injector... or your MAP sensor line either fell off, or is hooked up to the wrong nipple. The MAP sensor is the little black box bolted to the fire wall to the left of the master cylinder. There is a single vacuum line that comes out of the bottom and plugs into the back of the throttle body. There are actually a few different nipples on the back of the tb, and if you plug it into the wrong one, you will have problems.

 

First off (surprised no one else asked) but what other mods does your car have? Second, who installed the motor. If you paid 7k for this motor installed then it is the installer that needs be troubleshooting this. Third, I think you stall at idle due to a ECU issue not a fuel issue. Too little would stall you, not too much. You can have the biggest pump in the world. You have an aftermarket pump with stock injectors. Without increasing duty cycle on those injectors you'll never flow more fuel than stock, so you have not increased flow yet. Fourth, your mechanics is paying to repaint your bumper and replace what else was damaged by that flame. Fifth, who is this joker mechanic??

 

$7K is way to much to pay for a rebuild. It sounds like you paying for a lot of labor cause he doesn't know what he is doing. FWIW, I paid $5K including install and a Pineapple Stage 3 racerported motor.

 

I agree,have a look at your map sensor.See if it is connected to the correct nipple.Also check if your injectors are not leaking,that sometimes causes idle problems,but normally not this bad.

How does your plugs look? Are all of them black,or just some of them ?

All i can think off now.

 

I'm with him^

Mods?
Who built the motor?
Who installed the motor? Same guy?
Check that the injectors are not leaking and that the seals around the injectors are not pinched. That seems to happen a lot.

There was a thread recently about a guy whose motor was literally filled with fuel due to some problem with something was not installed correctly during the rebuild. Do a search.

good luck.

 

I seriously doubt it is a problem with the motor itself. Something engine management wise is not right.

 

This is a fuel related issue, have your mech check for leaks around the injectors. They are not seated right.

 

I ran my brand new engine with a streetport on the stock ECU just fine, ran great. After breakin I switched to my PowerFC and started putting the mods back on.

 

Just a shot in the dark but did you properly install those "mixing plates" (I think thats what they are called)? They are those crappy black-colored inserts u slip by the injectors.

 

Make sure the O-rings on the injectors are set correctly
or you might have damaged the injector screen and
caused the Injector to leak . .. also intailing it to spray
through the exhaust!

Jp

 

My car had the same problem, i had a seal blown. Checked with a mechanic and he told me my petit ecu caused my car to overboosted which inturn blew the motor. But the same idle problem.

 

There are so many ignorant responses in this thread, it's a little disheartening.

This is not an ecu issue at all guys. You can run every fricking mod in the book (except for larger injectors) and the car should still be able to at least IDLE on the stock ecu....

He is obviously choking with way too much fuel, which CAN cause you to stall or not run. As some of the others said, this must be a mechanical issue with the install (map sensor, ecu in limp home mode, injectors, fuel pressure regulator). BTW, way too much fuel will wash the oil away from the seals and greatly lower your compression.

 

I'd bet money that he pinched the o-rings while trying to install the injectors. It's an easy thing to do if it's not done carefully.

BTW, to whoever said "too much fuel can't cause the motor to stall" - that's not correct.
If you have a programmable ECU, try running the injectors static at idle. Come back and tell us the result.
Best,
John

 

O2 sensor....change it and see what happens. It's a $45 dollar part at www.oxygensensors.com. Mine went bad and had voltages in the 2.xx range so the pfc in O2 feedlack/lean run mode would dial out as much fuel as it could, then as it would stall, would add fuel, back and forth. not sure if the PFC kicks out error codes since mine didn't with the O2 bad.

Tim

 

Have you checked for ECU error codes?

I agree with rynberg. It's not the ECU. I have a street ported motor that idled fine on the stock ECU. I know of many other people with a good idle on stock ECUs w/ ported motors.

The Walbro pump may increase the fuel pressure at idle because the FPR cannot relieve the pressure. That would give you a slight richness.

-Jeff

PS Check for Vacuum leaks, spark problems etc.

 

Yeah I'm so happy that I have a pettit ecu becuase it raises boost for me. So does this mean I don't need a boost controller? It sucked on the stock ecu I couldn't get above 10psi I put the pettit ecu in and got like 19.

your mechanic fucked you in the *** my friend

rynberg what is goin on in this thread? I feel like a teacher set her class of retarded kids up with internet access to rx7 club to do an experiment or something.

 

mapsensor is located above the oil filter area, on the firewall, little black box with a hose connected to it

if you put a check valve there instead of a filter, it will only allow 1-way operation, that could be a possiblity

make sure you can blow both ways through the hose/valve, and that the hose is connected

could be a leaky fuel injector, bad install...pressurize your fuel system and hold your rails in the air and watch for leaks

then tap 12v+ and ground on the two terminals on the diff injectors, see if they leak after they spray

if that doesn't work, consider that you might have fouled plugs already, i fouled mine within 20miles of my first install

report back to us

 

Yeah. It's obvious it's a fueling problem, either from the injectors or some sort of sensor/ecu issue. It isn't "tuning"; something just is not working properly. JBurer may have nailed it.