Okay so I went to the last step of my insanity from the car, I bought a new ecm. It still did nothing. It is still backfiring and running from what i get to be rich when i start to get on it. It is also somewhat hard to start. I.E. I have to give it throttle to start, then it idles great. I can put it in drive and cruise at idle or 1k rpm around the block. Then it just starts backfiring. Then when i park it it also will start backfiring if i rev on it. Then after it sits idling I can freely rev it with no backfire, but it has some hesitation at the lower end.



Since owning this car I have put in these parts.


Spark plugs
spark plug wires
msd coil
alternator
summit distributor
walbro fuel pump
holley stealth ram
24# venom injectors
fuel pressure gauge
new battery
air and fuel filter are new
wideband o2 sensor- narrowband wire is reading to comp.
LT headers
a/c removal
converters removed
smog removed


Not sure if theres anything else, but I am not sure whats going on. Could I have possibly gotten a bad dizzy from summit? I also thought the only other thing to replace is the chip too. I also heard something aboutthe timing chain skipping a tooth or something

 

Also changed the MAF with a micrtech one, new fuel pump relay and maf relay

 

Is the SES light coming on?

What coil are you using?

What is your fuel pressure?

 

wideband sensor with narrowband wire feeding to computer could be a problem i think. widebands dont output the same signal as a narrowband so the ecm is probly not understanding anything and is freakin out

Does the car run ok when cold and in open loop, like you just started it up in the morning after a nights long rest? how does it drive during the first few minutes in that mode before the car heats up and goes into closed loop?

also are you running the megasquirt too on top of the stock ecm at this point? or are you back to stock?

 

I am completely stock right now. I do not have the megasquirt ontop of it. The car got scanned today and is staying in open loop. It also is giving no spark advance besides the base timing. I am using a msd blaster coil, fuel pressure is at 45 psi.

My ses bulb has been taken out, but i was throwing no codes

 

Kowboy59
To bring sanity to your car get rid of WBO for now. Install a heated NBO since you have headers installed. Heated NBO will insure that NBO is at correct operating temperature under all operating condition. It is also very common for a wideband controller to have an incorrect equivalent NBO voltage for a given lambda. Also, you should run a ground reference wire between WBO controller and ECM to make sure that the two boxes are at the same ground reference.

With that said what kind of dizzy do you have??? In a stock system ECM controls amount of timing advance via four wire interface and distributor. How is your dizzy is connected to ECM??

Oh yea, almost forgot - get SES re-connected. Tell us what it does during ign key off to run position transition. Does it blink on-off-on??


//RF

 

Micro tech (wells) they run alot richer (read higher air flow) then a stock MAF.

I had one on mine and it would always stall when put in gear, hot or cold, swap back to the bosch problem left. Ran real rich (wider injector pulse width) and the grs/sec were higher at the same rpms.

 

gonna have to recalibrate those MAF tables...take some air out of those tables to lean it back down.

 

Well I know that isnt the only problem. Like spark. That is my main problem. To be honest the microtech doesnt bother the car. My distributor is hooked up just like it should be.

 

yeah your tune is off... i'm not sure why tho, may be time to get your own tuning stuff and get a stock base tune back in there.

Check to see if your EST wire is connected and functioning right. It will show base timing when its disconnected, but willl add computer advance tables once its connected.

 

I had eveything put back in to when my car was working right. It just is not advancing timing what so ever.

 

well thats strange... something during the reinstallation of the oldstuff went in wrong. You'll have to trace the steps and go over everything to see whats up.

Start with the right NB o2 sensor and check that EST wire and distributor timing

 

Maybe the est wire (tan/black) at the ecm (d5) is not making connection. This wire powers a relay inside the dis module that switches from base to ecm timing. Check the ecm plug sometimes wires break or connectors slide up into the cover.

Check for a voltage to gnd at the est connector (at ecm and under hood), check it unhooked (base timing) and hooked (normal adv timing) should change (at dis)when connected. also look at the white (d4 ecm spark timing out put) and the tan/black wires at the dizzy.

My money is on an open tan/black wire between the ecm and the dizzy.

Key on d4 d5 = 0 volts

engine on d4 1.3 volts and d5 4.6 volts.