Engine spits and stutters when hot

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Engine spits and stutters when hot

October 31, 2007, 08:12:45 AM

Just bought a 86 Cougar w/3.8 to add to my 87 Cougar 5.0 collection. Looks like new recent tune up. Thing is when started cold it runs great. After engine reaches running temp when you start from a stop it chugs along not wanting to go and after being on the highway when come to a stop it just dies as if you turned the key off. Starts right back up and chugs along til you get up speed and then appears to run fine again. Seems like a fuel delivery problem but I would think it would happen all the time so I am up for suggestions. Anyone have similar prob? loking for suggestions. Thanks for input.

Engine spits and stutters when hot

Reply #1 – October 31, 2007, 08:34:22 AM

Codes? Fuel pressure check?

Engine spits and stutters when hot

Reply #2 – October 31, 2007, 09:03:53 AM

Just a guess but it sounds like a Control Module issue to me. I had one that would act like that.

Engine spits and stutters when hot

Reply #3 – October 31, 2007, 10:28:56 AM

Codes KOEO 13 63 KOER 31 91

Unable to get fuel pressure at this time..

Engine spits and stutters when hot

Reply #4 – November 01, 2007, 12:35:57 PM

Anyone with more ideas. TPS checked good but high in idle. Going to adjust down. It was 1.2 volts at idle. and 4.5 at full throttle and ramped nicely.

Engine spits and stutters when hot

Reply #5 – November 01, 2007, 05:16:38 PM

Quote from: chas jr;185569

Codes KOEO 13 63 KOER 31 91

Unable to get fuel pressure at this time..

There two groups of KOEO codes.
The first group to read out are the "on demand service codes". These are things the test routine finds wrong.

The second group to read out are the "continuous service codes"(memory codes).
These are codes stored in the keep alive computer memory while the car is running.

Since there is no on demand code 13 I am guessing the KOEO codes are memory codes.

13= engine not returning or slow returning to idle speed.
63=TPS voltage too low. The TPS may have a dead spot or the signal is breaking up between the TPS and the EEC.

These codes can stay in the memory forever if they are not reset.
They are reset by removing the test jumper while the codes are reading out. Or by disconnecting the battery.
If you don't know how old they are you should reset them and see if they reoccur.

KOER
31= EVP (EGR VALVE Position) sensor voltage is low.
Is the vacuum to the EGR valve unplugged?
91=Left O2 sensor reading lean

Quote from: chas jr;185748

Anyone with more ideas. TPS checked good but high in idle. Going to adjust down. It was 1.2 volts at idle. and 4.5 at full throttle and ramped nicely.

If the TPS voltage were out of specs it would have given a an on demand code 23 during the KOEO test.

The TPS is not designed to be adjustable. If the throttle stop adjusting screw and the idle speed control motor are in adjustment the TPS should be in specs.

Engine spits and stutters when hot

Reply #6 – November 02, 2007, 08:10:29 AM

Thanks for info. The first set of codes were 63 and 31 KOEO. I am leaning more towards a spark problem with the control module as stated above by blu84302.