1999 Olds 88

[deano55]

Hi all, I have always found you guys to be able to help so here it goes. My dads 99 olds 88 is running terrible, it seems to run on all 6 cylinders if you ease the throttle but if you give it too much it clearly isn't running on all 6 cylinders. At a standstill it like surges back and forth then rpm increases and, sounds like when the engine is cold you have the noise from the egr valve even when its hot. Going down the road it would run fine then start running terrible all over again. I was hoping it was the maf sensor but, I unplugged that and made not difference like my wifes regal did. I looked at the ignition wires in the dark but did not see any arching. My dad did say he had problems with cylinder 6 blowing off the plug boot, not sure how that could happen. We did put the car in gear a while ago and under brake load it ran smooth that time which was strange, it is off and one (missing stumbling). It is showing check engine on the dash so I will runn to autozone to borrow their code ready, maybe that will show me something. Any help will be appreciated

[RJolly87]

I won't even take a crack at it until I hear what codes it's throwing.

I would be curious to hear if it stalls or acts up when you pull the oil cap off while idling.

Is it consuming any fluids, and if so, what, and how much/how often?

[deano55]

made no difference how the engine ran when taking the oil filler cap off.
3 codes showed up
#1- throttle position sensor
#2- MAf
# missfire
when my wife's regal had a bad maf, it would run with the sensor unplugged but, would shut off when plugged in while hot engine,
as far as losing liquids there is 2 choices, coolant and oil, not sure what your getting at with that. Coolant and oil are full and not needing to add any. The coil packs, wires and plugs are 9k old. Hate to go start buying parts off the cuff. I unplugged each ignition wire one at a time while running, some seemed to pop/snap while others didn't, although seems that the engine picked back up when connected some. I bought the bluetooth code reader from advanced auto believing it would read real time like the one at autozone said would do, it appears the this one does no more than the torque app for 5 dollars did, actually less

[RJolly87]

What were the exact code numbers?

[deano55]

What were the exact code numbers?

oh no, I cleared them and they are not setting again. It does not surge up and down anymore. Took it on a ride, to much stepping on the throttle and it's missing terribly, stepping down on the throttle more and its detonating/ popping back. Easing on the pedal it will run smoothly and accelerate slightly. Dad had a fuel filter so I changed that out, barely could blow through it but, did not solve the problem. Had the ignition module tested and it tested good. I will test the coils later tonight then, tomorrow I'm pulling the plugs and wires even though they are only 9K old

[RJolly87]

My thoughts are gravitating towards a possible exhaust restriction, typically a clogged/broken catalytic converter.

Easiest way to rule that out is to unbolt the down pipe from the rest of the system to see if it drives any differently.

[deano55]

fixed, I kept thinking it was ignition problems after all this so, I swapped our Regal coil packs over to dads, runs smooth as should. I just wonder why the tps seemed stop the engine surging. Told dad not to buy the cheapest ones again.

[nos4blood70]

Cheap sensors are always a bad choice, they get hot and stop working pretty quickly in my experience. Glad you got it sorted out!

[1oldman]

my experience has been to get the coil packs from the salvage yard, AC Delco, part 19352925. I got to www.gmpartsclub.com to get most of my part numbers. - BC

[deano55]

my experience has been to get the coil packs from the salvage yard, AC Delco, part 19352925. I got to http://www.gmpartsclub.com to get most of my part numbers. - BC

ended up buying Borg Warner coils from advanced auto, 35 each, could have got ac delco from rockauto for the same priced but, didn't have the time to wait for them.

[1oldman]

ended up buying Borg Warner coils from advanced auto, 35 each, could have got ac delco from rockauto for the same priced but, didn't have the time to wait for them.

$35 got me and ICM and 3 coil packs at the salvage yard, but that was a while back. - BC