Was running fine and then strarted cutting out

[meanchicken]

Driving to work, had a couple spirited blasts :biggrin:followed by several miles of good cruising....a normal commute.

About 2 miles from work under normal throttle at about 45mph, the engine started to stumble/hesitate every few seconds almost with a perfect rythm.
Idles fine....runs smooth other than the stumble every few seconds. I'm letting it cool off before I take a look.

The only scan master reading that seemed odd was the BL would drop to 114-115 as soon as the stumbling started. Idle the BL is at 128...

I'm thinking maybe I have a loose hose letting air in after the MAF...any other ideas?

 

[meanchicken]

Didn't see anything obvious, so I nursed it home....25 miles....
Pretty much any amount of throttle makes it stumble and hesitate severely, but I could get it up to 45-55mph by gradually letting it accelerate through he stumbling. The higher the RPM or heavier the throttle, the worse the stumbling would get.

The BLMs pretty much stay at 115 with any amount of throttle and even at idle. When I take my foot off the gas, the BLM will momentarily go to 128-129 and then drop back down to 115 pretty quick and just stay there pegged at 115.

 

[RIFF RAFF]

did you put a hole in your innercooler ?

 

[meanchicken]

I dunno...not on purpose...

 

[TurboBob]

intercooler hose blown off,
injector harness issue,
bad MAF,
alky kit triggering early or siphoning,



trouble codes???

Bob

 

[larrym]

02 cross counts moving good?

 

[meanchicken]

cc's were counting and starting over...but should they move in a specific way?
O2's did seem high for cruising....high 800's.
All the IC hoses seem to be in tact and clamped but I need to check the ones that are down under the radiator and behind the grill. I've had that happen before and the car would barely run.
My TT chip has the fast update, so it does not give mal codes, but there was not a check engine light at all...no idiot lights at all.
It didn't use up any alky at all (tank still full) so I don't think the alky is barfing.
I'll need to inspect the injector harness for any obvious wear and tear.

Wouldn't the MAF affect idle? Idle seemed OK other than the BLM's hanging at 115 (means it's pulling fuel...right?), but tomorrow I'll unplug it and see if it makes a difference.

 

[GN owner]

Had a problem whereby the engine would stumble and hesitate for a few seconds and then work normally again and this would happen mostly during an acceleration from a stop. Problem turned out to be a bad MAF. The bad MAF would cause the idle to be around .800 on the SM and you could smell the gas.

 

[Pittsburghkid]

could be the maf or possibly the ecm. Just had a buddy go through that. Tried a good maf. then replaced the icm and coil pack still no fix. ended up being the ecm. Try tapping on it as it kinda fixes itself momentarily.

 

[machinegun]

I hate to say this but go for the easy stuff first.

Check all wiring and grounds

Check all plug wires, pull the plugs and check / replace with fresh ones

Check the coil pack is not causing you any issues.

Check for any loose connections between the maf and TB

After that then start looking deeper.

Really though check the plugs and wires.

 

[SHADOWII]

I vote MAF! Borrow one from someone close by. When I had a problem, mine would idle fine just don't step on the gas.

 

[meanchicken]

Plugs and wires are all good.
I just replaced the plugs 2 weeks ago when getting the car ready for smog testing, and also replaced one bad plug wire.
Passed smog no sweat other than the HC's tickling the limit, but that happened due to Cali lowering the limits again...

I'll try to borrow a good MAF after I take more time inspecting all the hoses and making sure I securely plugged my TT chip back in after swapping it back in for the smog chip I had in there temporarily.

I don't think its a wiring issue because I'd most likely be getting other indications like an SES light.

I'll also try to borrow good coil pack, ICM and ECM and swap one at a time to see what might be bad.

 

[williamsGN]

Had similar symptoms, was the MAF. You running the stock one still ?

I'd definitely check those hoses though.

Didn't you say something about putting the cat back on for emissions ?

 

[meanchicken]

Had similar symptoms, was the MAF. You running the stock one still ?

I'd definitely check those hoses though.

Didn't you say something about putting the cat back on for emissions ?

Yup, cat has been back on there for 3 weeks....was running fine with it on.

 

[williamsGN]

Pop the cat back off and see what happens. I don't know how many I've had to cut off when cars I've had started stumbling.

 

[dynoman]

Will your Direct Scan read the trouble codes or does the TT chip block them altogether. Try a 30 sec. or longer log on the Direct Scan, maybe something wiil show up . Sam

 

[Rodney87GN]

Speaking of Direct Scan....could be your DS maybe? If it's pushed on too far on the circuit board the ECM will do weird things. Seeing that you swapped chips recently for smog it's possible DS could have been disturbed...try taking off DS and see if it clears up.

Otherwise I'd does sound like a MAF related issue.

 

[TNTSNBS]

hey turkey, check the inside of the cam sensor, if the little tab broke off your cam sensor could be moving around a bit causing to stumble and do the weird things that you are describing, also if the coil pack module is going bad you would have similar symptoms, bad maf maybe but not likely..

 

[meanchicken]

All the hoses are OK.

I just let the car warm up this AM and every several seconds it will stumble at idle. I tapped on the MAF while it was idling smooth and it would induce a stumble...
I have not tried to drive it with the MAF unplugged, but at idle if I unplug it, the RPM drops from about 850 down to 675 or so. If I let it continue to idle with the MAF unplugged, it eventually stumbles so bad it wants to stall. The BLM's stay pegged at 116 at idle whether the MAF is plugged in or not and at idle the cc's are at 181 and not moving.

The cam sensor is fixed with an RJC kit since last year, so it should be OK.

I'll look at the direct scan again. I keep a 1/2 piece of rubber hose under the ECM in the kick panel to keep the DS cable form getting pressed on to far, but I'll make sure it's not the issue tomorrow.

 

[williamsGN]

Did you resolve this yet ?