Thread: Motor bucking and stalling..need some advice

Hey folks,

Well this is about helping me troubleshoot my problems so anyone with some kind advice would be much appreciated.

I just got done replacing a bunch of seals, lightweight flywheel, and water pump on the ve.

Well today I went to start it, primed the motor, fuel pressure just under 40psi, new spark plugs. Cranks over and fired right up.

Well right from the get go I could tell the idle was weird, if I revved the car to 3k and released it would almost stall, I attributed that to not running in a month and allot of work..etc.

Well I let it idle, and warm up and instantly realize it wont rev over 3k, so I check my coolant sensor, and n60 maf plug, everything checks out. I unplug the tps, car stalls, ok, then I start it back up and unplug maf, no change. Maf right? well I tear apart the maf wiring to check things out. Everything is connected. It had been running for over 2 months with the current setup. I reground, try again, it worked! Car seemed to rev fine. I let it idle to warm it up and go on the road. Come back 5min later, doing it again. I wiggle all the wires, and try unplugging the maf, no change in idle rpm.

Well I let it sit, went to dinner, come back, fires right up. No problem. Let it warm up for 10min, idling great. If I unplug the maf it stalls. So I think its fine. I start to take it down the road, afr's looked fine, normal. Well I get half a mile down the road car starts bucking like crazy, anything over %25 and its bucking at all rpms, not like limp mode, like fu*ked up mode. I get it up to 45mph and coast back home, it was idling. Get in the driveway and it sounds like it is stuttering when I give it gas, I try peddling it a little and it stalls out, it sounded almost like it was only on two cylinders before it died. Tried starting it, wouldn't even idle.

Coolant temps were normal, all ignition plugs seemed to be fine, however I am not ruling out wiring faults somewhere. However the current wiring setup was fine until I took the motor out and removed the harness and put it back in. No rad fans on or anything. Stock 02 sensor was in and plugged in. 1month old gas, again holding fuel pressure. No cel lights, however I did not have a laptop hooked up.

Sorry for the long windedness here, I am in the dark because the n60 maf has been fine up until now. I am positive it is properly grounded. The problem is intermittent apparently. And when I was halfway through the drive it really was running like sh*t, more then limp mode, so I am baffled. I am trying to find some information on testing the maf with a multimeter but haven't found anything yet. That is my next step. Oh, and Calum realtime ecu, stock injectors..etc.

Thanks,

Dudeman

Check your grounds - this same thing happened to me and it turned out I had forgotten to reconnect one of them. Also, test your MAF with a voltmeter - you might find that it has just hit the end of its lifespan.

After that, put in low compression pistons and boost it to 35 PSI. That'll fix all your problems.

^^ Agree.. Your MAF or TPS is probably not plugged in..
Probably forgot when setting your timing.. But this sounds like a dying MAF..
Did you loose the little MAF metal clip?? (u can make a new one with a paper clip)

I checked everything. If I unplug the tps the car dies.

The maf works part of the time, then it stops working altogether.

Anybody know where information on checking the maf is located?

The only ground I had undone was the throttle body grounds and those are back on.

Thanks.

Dudeman

Do you have any "cheap" silicone hoses run with your intake manifold?
Have you tried revving the engine while you are looking under the hood?
Your hoses may be collapsing when the throttle is applied.

I only have the IACV hooked up with some crappy ebay hose, because of its size.

I finally got the ecu hooked up to a laptop, I am showing a coolant temp sensor code (13).

I have unplugged it, and tried cleaning it, tried to check to ensure all the wires are attached and all, it all seems fine, however it keeps throwing the code. I am going to have a look around the forum, if anyone has any ideas please let me know. It has never given me trouble before.

Dudeman

Found a post by Dre a while back indicating if a plug under the dizzy is left open the coolant temp won't work. In my effort to be jdm wire ticked, my friend and I had accidentally snipped off one of the ends of the plug, and left the other open in the bay..... Just connected it and the codes are all gone. Waiting for some Honda Bond to dry on my fp gauge, then i will try it out.

Wish me luck, and thanks for all the help.

Dudeman

Good luck!
If the ebay hose is collapsing just go to autozone or something like that and get the right size rubber hose.

Ok here is the update.

I got it all ready, started her up. Started perfect idled perfect, no codes. Let it sit for 5minutes. Jump in the car and rev it to 3k and back a few times, sounds good. Then I hear the idle tone alter, and the afr's drop to 10ish. I check the code, sure enough airflow meter code showing, back in limp mode.

So I decided screw it I will tear out the n60 and throw in my old de maf. Get it wired in, and instantly in limp mode. Tried clearing the codes, and instantly comes back. Oh and I did change the tune to a de maf tune I had used before btw.

That leaves me %100 stumped. The ecu is disregarding the maf even though I have no idea how they could both go bad when sitting. The weird thing is it will use the maf for 5-10min, before it looses all drive ability.

Dudeman

woops