Ok this may be a dumb question but here it goes anyway. Will bad coils cause my max not to start? I got a p0300. Multiple misfire about two weeks ago. The car would struggle to start from time to time and if not warmed up it would hesitate and stutter. When I drove it would stutter on the highway when I would give it gas. Also if I stepped on the gas it wouldn't really rev or anything. But if I gradually gave it gas it would accelerate ok. However it still didn't have the power I kno that it should have. About a month ago I changed the plugs fuel filter and pcv valve. I also replaced the MAF about 2 months ago. What could it be?!?!?!?!

 

Also my mpg are in the toilet.. About 250 on a full tank!!!!!

 

anyone???

 

I think that the crank sensors are more likely causing the hard starting. I had 2 dead fuel injectors one time and the engine started almost normally. Check the crank sensors; do the resistance reading and clean the ends real good and see how that goes.

 

Also check the MAF sensor, and clean the IAC, I had a new MAF on my 95 and was experiencing some of the same issues with the throttle, good at low speed, nothing when I stepped on it, and no codes to go with it. Changed the maf, all good now.

 

the car should still start even with bad coil. unless they are all bad

 

yea man...i would start with the MAF. prolly have a bad ground there

 

ECTS

 

have new crank and cam sensors though

 

I had the same exact symptom way back and it turned out to be the fuel injectors. I had to take it to the dealer to change the injector. I am surprised that you only have one code. You should also get codes for all the cylinders that are misfiring. Is the check engine light blinking when you are pressing too hard on the gas?

Once you change your fuel injectors, I recommend you change your fuel filter too.

 

could be the air temp sensor, it connects to the air box. What is that max in your sig lowered on?

 

IF you want to eliminate the coil pack as your problem, you can try wrapping all the coil pack shafts at the buttom with good quality electric tape and see if it helps. I once had hesitation issues and I did this and it fixed my problem.

 

I'm having similar problems.. I am going to try a buddies maf and see if that helps at all.. Not to steel your thread, but does anyone know if my O2 sensors could be shot due to a dented y-pipe? That's my only other thought, unless it's a bad coil that's not showing a code, but I don't have a multimeter to test them.

 

i ordered new coils so ill do that and hope that alleviates my problem... if not then maybe ill have to get another maf

2.2 in the front 2.0 in the year

 

Anyone else have any imput... It's not the MAF

 

Have you tried replacing the ECTS that Maxima_Joe suggested? They only cost around $25 at autozone. I baught one from autozone several years ago and it's still functioning.

 

yea i replaced that about a month ago.

 

Do u have a intake system? And try changing the iacv with someone else. And how many miss fires do u have?

 

yea ima say the cliche thing...throw some chevron techron in the tank and see if it responds.

Multiple misfires leads me to believe that its not an isolated sensor, it has to be somehtign that affects all cylinders. Thats the maf, crank sensors, cam sensor, grounds, and ECU.

Make sure u got no vacuum leaks. What kind of plugs did u use?

 

Maf will NOT prevent the car from starting, only thing you need to start a car is a working starter, fuel pump, a couple of injectors and a couple of coil packs working.

Now the items that control those things are as follows:

Fuel Pump is controlled via ECU
Injectors are fired via Camshaft POS sensor
Coil Packs are fired via Crankshaft Ref/Pos Sensors

I can't imagine a ECTS making a car NOT start at ALL (hard start? Hell yeah, but not total prevention)... Hell I'll go and unplug mine tonight to see if my car won't start.

It's really down to those things and what controls them... The max doesn't need anything else to start...

 

Here's what it will do. The first time I start it it will start fine... I drive it around there's hesitation. It's misfiring. No Cel but when I plug it up there's a random misfire code. And has mileage is in the TOILET!!! But after I drive get to my destination, if it doesn't sit for at least 45 mins, when I start it the car start then starts idling really bad car shakes and stalls. So then I have to wait til it decides it wants to start again.
I kno it's not the sensor since I just had the cam and crank replaced in Nov. I also cleaned them the other day to see if that would help. I bought another Maf to see if that could help. And no change. And since I have the misfire and the p0300 code all I can think is that alot of them have to be bad.

 

Did the techron also... No change.
Also when I rev it just sitting in the driveway there's a loud pop/backfire coming from the intake..

 

u check the TPS?

 

Don't need it to start your car..... but it could explain the other problems....

ECTS!!!!! Among bad knock sensor and or coil packs.

That line in bold screams ECTS to me.

How about you invest in a program called ECUTalk, the program is free but the cable is expensive, well worth the cost, you can get REAL TIME data straight from your ECU, very easy to tell if your ECTS is bad or not.

 

Post #17.

Maxxxdout already replaced the ECTS.

 

think the TPS is gonna be the next thing to do since the coils didnt seem to alleviate the problem. While i was under there i cleaned the throttle body and iacv also. Took it for a ride and came back to the house and now theres a loud high pitched screaming squeal sound coming from that area somewhere. COnsidering that i was out there for a decent amount of time and its starting to get dark, I didnt get a chance to see what was what, but what the Hell could that be. I put everything back exactly how it was. However i did find a nice sized rock of carbon in the top of the egr tube where it connects to the manifold. It was a piece with the diameter of penny and about 4 pennies thick..

As far as the TPS goes, past those two little stupid screws is this a diffuicult thing to do or is it as simple as the other sensors where its just a swap out.

 

o2 sensors will cause bad idle and drivability issues that will start after the engine is warm and they have the hand off from the IACV. only need the upper O2 lower dont adjust air/fuel.

 

No. You're just plain wrong, and poor English.

 

lol how do you figure?

IACV adjusts air/fuel when engine is cold Then o2's take over! That is just plain fact.

 

I have no O2s, and have ran with out a IACV on occasion sans O2 sensors.

That's how.

Edit I guess if the OP cares to know, I have a long start when the car is cold, that I suspect is due to a failing fuel pump, the first start of the day is the hardest for my car, but I've had this problem since day 1 with the vehicle when it was damn near stock.

 

Ok.. So what should I be lookin for... Since we have established what I'm not supposed to be looking for thanks to aackshun and bronz... Lol.. Besides o2 sensors were also replaced in like April.. The front two anyway.. The rear one is still and old one...

 

Buy ECUTalk and cable, report results, we can move on from there...

Also for lolz install a Fuel Pressure gauge.

That should do it for most of the stuff you can monitor... Hell I think between those two things you can spot the problem if not, then that REALLY narrows things down.

 

from what i just looked at on that ECUTalk website, they are currently out and also they are only pc compatible from what i see and i have a Mac... So i dont think thats an option for me. But considering that it is still misfiring from what i can feel after i drove it today that just points me to injectors.. However i still have no codes...

 

There's a program for Macs also!!!!

I have to look it up later tonight....

 

k

 

with no o2's what sets your air/fuel mix?

 

Automotive oxygen sensors, colloquially known as O2 sensors, make modern electronic fuel injection and emission control possible. They help determine, in real time, if the air fuel ratio of a combustion engine is rich or lean.

The ECU attempts to maintain, on average, a certain air-fuel ratio by interpreting the information it gains from the oxygen sensor.

Symptoms of a failing oxygen sensor includes:

• Sensor Light on dash indicates problem
• Increased tailpipe emissions
• Increased fuel consumption
• Hesitation on acceleration
• Stalling
• Rough idling

http://en.wikipedia.org/wiki/Oxygen_sensor


owned!

 

i have heard of clogged EGR tube causing stalling. Misfiring tho...idk about that.

I find it hard to believe that so many injectors could fail all at the same time. Especially if u running the techron .

I would look into the TPS first then EGR tube. The problem has to be something common to all cylinders.

 

Default rich map on the ECU.

[*]Sensor Light on dash indicates problem - Duh, my CEL stays on... EGR code (it ain't there), all 3 O2 sensors (took out the fuse), and that's actually it... The other codes won't light the CEL, they're 6mt swap related.

[*]Increased tailpipe emissions - Yeah...... Duh.....

[*]Increased fuel consumption -

Say whut?

[*]Hesitation on acceleration


seems fine to me

[*]Stalling - only n00bs stall


[*]Rough idling - that's due to MANY other things... But for the sake of argument I will concede that to you... Even though I had idle issues before I said fck it to the o2 sensors.


I will be real, the car runs like *** (STUPID rich) in open loop when the car is warming up, but once it reaches operating temperature it's fine.

And I ran w/o a IACV for a hot minute because I was playing around with intakes, didn't have a hole for the IACV.

I'm up for next the round

 

yeaaaaa boiiiiiiii!