Hesitation / Miss...

SS/GNX

Formerly NothinYet
Joined
Feb 13, 2007
I put some borrowed injectors in the car with a chip from TT and now my car has a hesitation/ miss.

Under about half throttle or more, it stumbles or misses for a second.

I just had my coil packs tested, and they tested OK.

I pulled all my plugs and they all seem to be fine too.

FP is good and consistent....

Crank Sensor is only about 3 months old, is an AC Delco, and was in place properly.

Tried another MAF, but that made it run like cr@p, so the other one is bad, but this one seems good, run perfect at idle/cruise speeds.

Just under any kind of acceleration is when the problem occurs.

Any suggestions?

Im gonna try pullin the harness to the cam sensor off and give it a drive and see what happens.
 
Did you have the miss fire before the injector change? Are the injectors known to be good? Were they sitting with old gas in them? A clogged injector can give you those symptoms.
 
Did you have the miss fire before the injector change? Are the injectors known to be good? Were they sitting with old gas in them? A clogged injector can give you those symptoms.

Not exactly, my buddy said they were good, but they were sitting for awhile, I know that. So could be bad/dirty. Luckily I bought a set of 30# injectors with 3 chips for $55! So I can give that a try too...

That was actually my first thought as it did happen right after I swapped them out, but I never want to leave any possibilities out.

So im going to try both. Im still open to any other suggestions too, in case I try these two things and it doesnt work.

This way, I have an entire list of cr@p I can do/ try.
 
did you put the plugs wire back in correct order when you pulled he coilpack to do the injectors, a mixup of any two wires on same side of coil (such as mixing up the 3 and 5 ) will still run abut with a slight miss but the miss isnt really as noticable as when under load


did you mix up an injector wire , they have numbers on them
 
did you put the plugs wire back in correct order when you pulled he coilpack to do the injectors, a mixup of any two wires on same side of coil (such as mixing up the 3 and 5 ) will still run abut with a slight miss but the miss isnt really as noticable as when under load


did you mix up an injector wire , they have numbers on them

wires were long enough, so I didnt have to pull them off.. just took off the coil pack and moved it back a half inch away from the fuel rail and done.
 
Is it the correct chip for the injectors?

Eric

I HOPE so....

See I thought about this too. I was told by my friend that these are 40# "redstripe" injectors, so that is what I had TT burn me a chip for.

But How can I be certain thats what those injectors are? Are there numbers on them I can check to be sure?
 
There are numbers on the injectors & if they are 40# Lucas Red stripe injectors the # should be 5208008
 
UPDATE:

OKAY... This car is crazy. Thinking that it may have been the injectors, I swapped them out AGAIN for a set of 30# ers with a chip that I got from a member and he took it off a good running car.

Car still is giving knock like CRAZY! My casper gauge is in the red and the scanmaster is showing about 4 degrees or so, and this is under normal acceleration, NOT pushing my foot to the floor!

I dont know what to do. I need your help.

What can cause all this false knock and the sputtering?

Anything to try?
 
I had a similiar prob hesitation
changed cam sensor, coil module, crank sensor
ended up being the spark plug wires gave up the ghost.
bought a set of new msd wires off fleabay for $50 plus ship

but ur prob sound like a coil/module prob
 
Crank sensor and MSD wires are brand new... 4 months old at the worst.

I had my coil pack tested, and the middle coil packs only seemed to have a problem around 7-8K rpms, which I would never reach, but maybe I should try borrowing a known good coil pack just to confirm. I checked all the plugs and they all seem fine, nothing rich or lean.

Would a bad coil pack cause the crazy false knock?

Thanks for replying!
 
Sounds like a problem I had back in '89. I found that my injector wiring harness was not up to snuff, had some broken, brittle wires. Maybe in the process of swapping the injectors you might of moved the wires one more time than they liked. Might want to look there, worth a shot.

Also, I just repaired an '92 Olds with a 3800. Similar systems but it was the crank sensor. It had come loose and was walking around and getting chewed up.
 
Well, the injector harness sounds like a good idea to check out... could be that. It IS old. Great idea, im gonna take a look at it. Thanks!

Not the crank sensor though, checked it.... snug and in the correct spot. No rubbing.
 
Well, I had time to take a look at the injector harness, and the wires dont seem broken or brittle anywhere, matter of fact they are very flexible and seem in really good shape, but I guess its still a possibility.

I also tried another coil pack, and it did the same exact thing.

Its weird.... Its not even running funny at lower speeds and RPMS, but the knock gauge is going all over the place.... Looks like someone is putting on a light show! Scanmaster is picking it up too... Really strange.

HELP
 
My car had the exact same problem a month ago for about 3 weeks. Checked everything from MAF to computer. For me it only happened after the motor was warm, and as soon as i touched the gas it would hessitate bad and then clear up if i gave it about half throttle or more.

The problem turned out to be the Cam Sensor. It wasn't bad, but was not adjusted correctly. Check yours and make sure it is positioned correctly, and that it is working. Mine was just a little bit out of adjustment, and as soon as that was fixed it has been running awesome ever since.

Eric
 
I had the same problems as you. I'm new to the Buicks and don't understand them that well but I replaced the wires, plugs, coil, ignition module, egr valve, and removed the cat and nothing changed. Last Saturday I changed my TPS before I went to the meet at Busse woods and car runs almost perfect, I still need to adjust the TPS properly so it runs perfect, but for just pulling the part out of the box and slapping it on there was a night and day difference.
 
Could the cam sensor or TPS sensor cause the crazy false knock ??

I cant figure out what is causing that.

I will have a friend of my check the adjustment on the cam sensor as soon as he can.

Keep them ideas rollin!
 
not sure about the TPS but an incorectly set cam sensor could produce knock. Mine didn't but i wouldn't waste anymore money untill you at least check to make sure it is positioned corectly and is functioning.
 
Top