car runs fine then when gets to running temp it starts to surge i notice its starts round 2000 rpms jumps up to 3000 then down to 1000 then eventually stalls out like its flooded. Machanic said itsloss of ignition but the egr va*** hose is broke in half n pinched off. Machanic says he is positive this issue wouldnot cause the problem im having he said egr is for etest n will not make car stall out just run ruff. i changed wires coil packs map sensor as well i got a used map sensor from wreckers car runs bad withthat still when i unplug the map sensor the car runs better but for sum reason i think its the egr causein the surging n poor running all i want to do is drive my cadillac n no one can figure this out

 

An EGR valve that is physically stuck open will definitely cause the engine to stall. I've had trouble with the EGR valve in my SLS until I finally bought a new one from GM. With it running that bad, there has to be some codes set. What are they, do you know?

 

there is a lot of codes imnot sure which ones tho even the guy at the shop was confused do u think it cud be bad crank shaft sensor that i herd wud cause sparatic ignition loss n witht he egr hose cut in half n pinched off im sure that is not a good thing lol

 

Post codes

 

Hi, everyone. I have a 1993 Sedan Deville 4.9 engine that is doing similar things. 158k miles.

engine runs a bit rough. after driving approximately 150 miles in one day, engine will start to die in brief spurts. it acts like it's gasping for fuel. This will start out very subtle, and increase in severity until engine dies. leaving car off for 2-3 minutes will alleviate problem for approximately 10-20 minutes down the road. then i will have to turn the car off to get a bit further down the road, although the problem-free intervals decreases each time.

What i have tried:
1. cleaning gunk off throttle blades (is this coming from PCV valve)
2. running without air cleaner (suspected breathing/restricted airflow)
3. changed 5 of 8 plugs. plugs in front of the engine were corroded with white deposits. first plug on back side of engine had no deposits. (i ran out of time to change the rest)
4. tried adding more gas, suspected problem could be due to debris in gas tank that takes effect after half a tank was burned off

trouble codes (displayed from ECC interface):

E 13 - Oxygen sensor not ready (does this mean i have to replace it?)
E 40 - Power steering pressure switch open (????)
E 52 - ECM memory reset indicator (????)
E 53 - Distributor signal interrupt (???? - bad plug wires, coil, ????)
E 85 - Idle throttle angle too high (this seems straight forward enough).

 

you know all the codes, but the problem is there are many of them
and they could be set by the car stalling so we call them false codes

you could track each one down, but that could take a long time
the easist way is to erase the codes

when the problem happens again
write them down
and start there

i would check spark plug cables for grounding
the dist cap

the ignition module inside
just do a visual look make sure no damage

you have a part heating up and causing the problem once cool it works fine (modules areknown for that)
i would check fuel pressure as well

 

I swapped out the front plug wires ( i hope to finish backside plugs and wires this weekend), decreased the idle speed/throttle idle angle, performed an inspection of all the wiring harness connections, and cleared the codes.

I turned on the car and let it idle for a few minutes and then ran the codes again. i got E 85 - throttle angle still too high. No other codes were displayed. Anyone know where it should be set? The other day i adjusted it too low i guess, it kept loping down and wanting to cut off.

So - on my 85, i am supposed to be able to enter an engine diagnostic data section after the initial codes are displayed. The readout goes to .7.0, then if i press and release the fuel reset button, i will go into the engine data mode. it's supposed to tell me all kinds of neat stuff about throttle idle angle, spark advance timing, etc, etc.

I tried doing the same thing on the 93 deville and got nothing. Does anyone know how to get into engine diagnostic mode (sorry i don't have a shop manual for the 93 yet)? I suppose there's either a different button to press or the computer is failing to go into engine diagnostic mode.

i will carry around pad and pencil to record any new codes once the car starts sputtering down, as suggested.

 

well i drove 240 miles today with no sputter down and die issues. prior to leaving i finished swapping out the last plugs and wires. i repaired a vacuum hose i noticed was broken close to where it connects to the throttle body. i also threw some of the fuel system cleaner in the tank prior to filling up this morning.

is the issue resolved? probably not. it was still running a bit rough in places, but apparently not enough to store any new codes, however.

 

well today i replaced the distributor cap and ignition coil. also cleaned off some of the electrical hook ups with contact cleaner. we'll see. still no new error codes.

 

ok, so according to some research i have done, a problem with the throttle position sensor can cause the issues both myself and the OP are having.

i will try to perform the functional test tomorrow after work.

seems like this could be a good bet since the symptoms match, and the trouble code i'm getting also points to the TPS.