Dead Hoe

[AnderbrA]

Heres the issue, the car runs very rough if at all at idle and you cannot give it any gas. As soon as you do, it bogs down and dies.

Codes pulled p0300(i think) Random Multiple Misfires, basically getting misfires by the hundreds on all cylinders.

Replaced the fuel filter, swapped the entire IDI cover and coils....same thing....cannot figure it out for the life of me... The injectors have proper voltage, TPS seems to be working via the scanner. Fuel pump relay fine.

Diagnostics for that code states either sensor or ignition problem. Where in there it is i have no idea....The only thing I have not done was get the fuel pressure reading to make sure the fuel pump is working properly, but have no way to check it.

Gimme ideas please, I just spent over 2k in this motor and now it does this shyt. I just said screw it and went out and bought a brand new motorcycle, but now its getting too cold to ride it every day....need to fix the hoe!!!

[b-spot]

Sounds like your ignition module is toast to me. Same thing happened on meh ecotec.

[AnderbrA]

swapped out the entire IDI cover....coils and ignition module....did the same thing. We tried some starting fluid and wd40 in the intake and it did manage to idle a lot smoother for a bit, so we are thinking the fuel pump may be getting weak.

[jamcllw]

Do the 2.4s come with a maf sensor? On my 1.3 DOHC Suzuki engine if the maf isn't connected it will idle but will die as soon as you give it gas.

[keepitsimple]

there is a sensor, i believe its the plug on your throttle body all the way to the right, the 3rd one

[AnderbrA]

there is no MAF sensor on the 2.4 the main sensors on the TB is the Idle Air Control, MAP, TPS and some vacuum connections...

some progress.....its not the fuel pump, i finally checked the pressure at the fuel filter and I am getting 40psi when the pump engages.

so basically back to the drawing board.....

[Oldsman]

are you flooding the hell out of it?

is your TPS reading correctly?

are you using a 2.3 or 2.4 TB.

get a wide band so you can read if she is running rich or lean.

check spark plug gap. possible change spark plugs. what brand and heat number you running. is it stock heat rating?

what about the knock sensor?

i think you should have a full diagonistic ran on it to give yourself more if.

[AnderbrA]

nope not flooded, not doing anything with gas,

TPS reads correct % of throttle whether car is running or not.

stock TB and IM

ODBII scanner showed 0% lean or rich

new spark plugs, had bosch +4s, now have NGK

Knock sensor should throw code, and retard timing.

any other ideas....

[nguyen187]

Try Checking the ground! When i put my motor back in for some reason it didn't run right, so i just upgraded a direct ground from the battery to the block. Thats probably not gonna solve your problem.

ANother issue that helped the first time i rebuilt my motor was that the o2 sensor (precat) went bad, got a new one and she ran like a champ! i would around there as well.

Good luck and keep us updated!

[AftermathAlero]

PCM problem? maybe

[Fast Eddie]

Plugs wires crossed?? lol

Could be a bad cam or crank sensor, those are used to trigger the ignition, never heard of one failing but....?? Also the knock sensor will only throw a code if it senses knock, not if the sensor is bad or malfunctioning, gotta love OBDII :rolleyes:

FWIW those sensors cost $19-$33, a piece, from autozone online.

[AftermathAlero]

Originally posted by Fast Eddie@Nov 4 2005, 04:10 PM
Plugs wires crossed?? lol



2.4 dont have plug wires.

[Fast Eddie]

Originally posted by AftermathAlero+Nov 4 2005, 11:01 AM--><div class='quotetop'>QUOTE(AftermathAlero @ Nov 4 2005, 11:01 AM)</div><div class='quotemain'><!--QuoteBegin-Fast Eddie@Nov 4 2005, 04:10 PM
Plugs wires crossed?? lol



2.4 dont have plug wires.
Quoted post
[/b][/quote]


DUH, hence the "lol" :banghead:

[AftermathAlero]

Originally posted by Fast Eddie+Nov 5 2005, 06:15 AM--><div class='quotetop'>QUOTE(Fast Eddie @ Nov 5 2005, 06:15 AM)</div><div class='quotemain'>Originally posted by AftermathAlero@Nov 4 2005, 11:01 AM
<!--QuoteBegin-Fast Eddie@Nov 4 2005, 04:10 PM
Plugs wires crossed?? lol



2.4 dont have plug wires.
Quoted post



DUH, hence the "lol" :banghead:
Quoted post
[/b][/quote]

DOH! .. that was when i just woke up in the morning at 11am. Went straight to computer for the usual forum browsing.

[AnderbrA]

I am going to try the crank sensor tonight....it would have more relevance than the cam sensor.

[nguyen187]

ignitions system definately fails, cause mine did! Check it all!

[brim]

plugs aren't soaked? no delivery? Does it idle fine all the time till you give it gas?

I'd say it's the FPR if anything, the pump may be a good idea too tho, but I dunno.

Have you ever gone through constant starts and pulled the plugs to see if they're stinkin like gas?

old spark test, use a screwdriver and see if they're producing

seems odd anderbra

[Super White Alero]

Wowo It's been ages since I posted.

P0300 Random Misfire detected.

First, clear the code. Test drive using OBD II scanner set to record data, Set recording info as follows O2S2, MAF(hg), CAL Load, IAC, TPS(%), Vehicle Speed, MAP, Fuel Trim. Set condition for code trigger.


When the code trigger the recording You will have the nesacrray info to view not the junk thats irrevlant.

After clearing code, P0300, and either P0301, P0302, P0303, or P0304 should appear, By narrowing down to two codes, you can determine which cylinder is actually misfiring. Since we don't have wires to check for spark, The only way to narrow this down is to do a functional test using OBD II. Since Im assuming this is a project car Bryce you might not have the need tools.

In this order, remove one spark plug boot from the cylinder replace cover and hook up test motor, if the motor is still the same that means you found the faulty cylinder, if the motor is running rougher than before you removed the boot, then that cylinder is good.

Once the faylty cylinder is found. you need to determine if spark is the issue fuel, or compression.

First check to see if spark is working by removing cover and placing a old spark plug in the boot put the tip on a good ground in the engine bay. (Note make sure not near the fuel rail, and make sure no carb cleaner near the plugs, Have friend crank the vehicle. if all four plug are sparking then ignition system coil is ok. If none or more not sparking, then could be PCM, Ignition system, Camshaft postion Sensor, grounding or muplty things.

Move on to Fuel, check using an led atteched to a good length of wire. Connect injector wiring harness(DON NOT REMOVE INJECTOR FROM MOTOR) to the led. Have friend crank motor if the led lit up then injector is reciving power. If not, possibly grounded wiring, PCM, CPS (Crankshaft Postion Sensor),

Check for compression using a compression gauge. HAve frined crank motor. Check the pressure. Since Im home today, I don't have the PSI it should be but check to see, if the intake is leaking air, head is leaking or what.

Hopefully this helps you get started. The best way is to figure what is the cause. A code only gives you a system. Tried to narrow it down to a system or component,.

[AnderbrA]

brand new rebuild, forged internals.

new plugs

p0300 is even after codes are cleared.....equal number of misfires for all cylinders.

replaced crank sensor...no change

swapped ignition system...entire top end...no change

fuel pressure approx 40psi at fuel filter

new fuel filter

idles hardly.....and hardly idles....very rough half the time it dies.

no other codes, sometimes the trac off light will randomly come on while its trying to idle...

we used the odb ii diag scanner, not just a code puller, i guess i dont know what the specs are supposed to be for each sensor etc. but nothing looked out of the ordinary.

TPS functioning properly

not lean or rich

[PlainOldOlds]

:rolleyes: Originally posted by AnderbrA@Nov 14 2005, 07:38 PM
sometimes the trac off light will randomly come on while its trying to idle...

[Fast Eddie]

Crank sensor (http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/19/1e/34/0900823d80191e34.jsp)

Cam sensor (http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/19/1e/47/0900823d80191e47.jsp)

You are 100% positive the cams are timed correct right?

[AnderbrA]

wow finally some resolution....took it down to the dealership finally.....they did the exact same thing that we did.

they checked all the ignition system....all diagnostics passed, everything appearred to be good.

one of the service technicians had a vehicle with the same motor...they swapped out the top end(IDI cover) and my car ran perfectly.....so something in that whole assembly is bad...

here is the confusing thing.... cylinder 1 and 3 are not firing consistantly, but as the coils work, 1 and 4 are on one and 2 and 3 are on one....so it cannot be one of the coils....

they swapped out the coil assembly and didnt get any results, so they are tearing apart the whole assembly and troubleshoot it piece by piece rather than throwing parts at it....should find out today what the exact problem is. They are thinking one of the circuits is fried someplace. Either in the harness or in the ignition module, since that is the only thing that is left except the 2 coils.

[keepitsimple]

sweet glad to hear u almost all set

[AnderbrA]

spoke too soon, they thought that was it, but only let it run for a couple seconds so it still has the problem

service technician said it has no vacuum at the intake. No leaks.....he said it has to be something mechanical...he tore the head apart to check the valves etc...everything was fine....so the only other thing he thought it might be is the oil pressure valve getting stuck causing it to have extremely high oil pressure making the valves not seat all the way.....

he checked that today and everything is fine with it....

so back to the drawing board.....he insists there is a problem with the valve train.

any ideas....they have exhausted their resources....

[Super White Alero]

Bryce pm me your email I will send you the diagonstic procedure.

[AnderbrA]

they dont know whats causing it...the only thing they said that was left was to tear apart the engine....it was a fresh rebuild professionally.....

I am having them try 2 things still....

replace fuel pressure regulator
flash my spare PCM and install it.(in case it is a computer issue)

[Oldsman]

what cams did you use? maybe throw back in the stock cams. also replace the intake manifold( possible cracked) and have head rechecked for cracks.

[AnderbrA]

They checked for leaks and cracks...nothin there....i used the cam swap cams....they worked fine at first.


95 intake
93 exhaust

[keepitsimple]

so u think its the cams?, has anyone else who did the swap had a prob?

[Oldsman]

Originally posted by keepitsimple@Nov 30 2005, 01:47 PM
so u think its the cams?, has anyone else who did the swap had a prob?
Quoted post



my cam swap went great and the motor loves the cams.

[Oldsman]

so lets see here............

they swapped out IDI cover and car ran good then they tried just coils but NG. i take it they tried just module and NG. now if they changed the IDI and it ran good something rest or something was reading correctly til it got a bad signal. did you ever change out the cam sensor? maybe try putting the stock intake cam in to see if the sensor can read the stock cam fine but maybe the gap between the sensor and pickup point is too much and doesn't read accurate.

now if a senor is reading wrong it would have the computer doing funky stuff and screw up timing to were vacuum would be screwed up. have you double and triple check the cam timing? is the tensioner working right.

[Fast Eddie]

HMMM...
THe car only ran good for a few seconds with the IDI swapped out, possibly due to the computer resting when the batt was disconnected. I would test the cam sensor before replacing it. Also the crank sensor is more involved in the timing algos i've seen, and that is fresh (not that that is a guarantee of a working part). Even if it was screwing up timing it would have some vacuum, a running engine produces vacuum. Is the TB working smoothly and adjusted correctly? What are your compression numbers?

If you have the same two cylinders not firing and the other two are, focus on those cycls. It sounds like the valvetrain was checked and then rechecked. I would NOT have em pull the engine apart again at this point. esp if you have good compression and oil press. its probably not the bottom end; and IF cyls 1 and 3 are not firing, even with a diff IDI assm. then its probably an issue in the harness, PCM or plugs, definetaly in the ignition system, including its sensors, NOT mechanical.

Now if they are firing you may want to look at your injectors and make sure they are spraying those cyls, not a difficult thing to check. Also retake your fuel pressure at the rail. It sounds like the problem is in the ignition or possibly in the fuel system.

[AnderbrA]

ok I had them replace the fuel pressure regulator and use my spare ecu and flashed it....everything is still the same.

to recap....EVERYTHING that we have done so far has had NO RESULT.

The only think I can think of that is left is bring the stock cams in and have them swap them.

Scott and Eddie, give me a call and I will go through things in detail with you.