Engine High Idle, Rough Start

i know where a complete distributor with cap and everything sits. if this is the problem what should i pull from it if not the entire thing? i can grab it all friday for dirt cheap more than likely...
Grab the entire thing. To change a failed or possibly failed PIP you have to press the gear off the bottom of the distributor. It's too much hassle when you can easily get an entire distributor.
 
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this is out of a 1990 5.0 sedan. the distributor cross matched exactly. will the pip and all the rest be the same? what is the actual name of the pip if i were to go to the part store and ask for one so i can cross match it before i decide to pull it?
 
The PIP sensor inside the distributor isn't easy to test without an oscilloscope engine analyzer. It can and will cause strange problems.


From the Cranks OK, but No Start Checklist for Fuel Injected Mustangs - see paragraph 1 B

B.) PIP sensor in distributor. The PIP sensor supplies the timing pulse to trigger the TFI and injectors. A failing PIP sensor will sometimes let the engine start if the SPOUT is removed. See paragraph 5A – Using a noid light on the fuel injectors will tell if the PIP is working by flashing when the engine is cranking.
i had ran a noid light on the fuel injectors weeks ago. it flashed in a "normal rhythm". will run without spout tonight and report back.
 
and... took the old dizzy out went to get the other one and it has a cast gear. so put mine back in, lined it all back up and played with the settings a little. car will run forever... perhaps it is time to step back and start with a new cap, rotor etc...
 
ignore the previous post. nothing has changed. dizzy i was going after is wrong, may have a new used one tracked down to try. changed the ect sensor even though the last one semed to check out. just in case. still on a cold start it fires, runs at the initial high idle and then when the rpms decrease it bogs down and dies. sometimes it struggles to stay alive, sometimes it never gets a chance to try. had it running for 20 minutes today after repeated times of trying to start it. only difference i can tell is that when it finally started and ran the engine temp was up from the continuous cranking. still no codes on koeo, cant get it to run long enough for koer codes. any ideas?
 
Beg, borrow or rent a vacuum gauge to test for vacuum. Your local auto parts store may rent/loan one. You should see 18"-20" of vacuum at 1000 RPM.
 
Beg, borrow or rent a vacuum gauge to test for vacuum. Your local auto parts store may rent/loan one. You should see 18"-20" of vacuum at 1000 RPM.
got the tester, not sure how i am going to test it with it not running... any advice? can you apply vacuum to the engine while it is not running and look for leaks that way?
 
smoke puffing out around the egr. cleaned both mounting surfaces up and going to get a new gasket. nasty $1.50 cigar by the way...

also coming out near the carbon canister vents. this may not be a problem as they are "vents"?
 
got it up to operating temp. now it starts and runs. 18 mmhg at 1000rpm around 16 at idle. will start run and restart with no problem now that it is hot. ran all codes only 11's koer and koeo cylinder test is 9. i am at a loss. been running for 30 minutes no problem. restarted 6 times no problem.

what could it be? going to let it cool off and try again, see if it is indeed a cold start problem or a sitting in the garage for days problem.
 
alright, let it sit for a long time. engine cold. try to start and same thing. won't then hard start, idles high then slows as usual then rough and dies. till eventually the engine is warmed up to the middle of the guage ("normal" temp) then one more hard start and it idles down and runs perfectly. i smacked the distributor cap with it running normal and it bogs... perhaps this is the cure. new cap and rotor or whole new dizzy?
 
I am glad to hear that you got it fixed. It has been a very interesting time trying to do remote troubleshooting. By now you have a very good understanding of what can go wrong and how to find the problems.
 
I am glad to hear that you got it fixed. It has been a very interesting time trying to do remote troubleshooting. By now you have a very good understanding of what can go wrong and how to find the problems.
i have learned a ton. your knowledge and the patient approach of not just throwing parts at a problem got me back on track. otherwise i would have an empty wallet and a non running car.
as a side note i am thinking that with all the electronic failures in this car someone must have done something like hook a battery charger up backwards or jumper cables. fried it or something. computer and a ton of sensors... something happened.
 
i have learned a ton. your knowledge and the patient approach of not just throwing parts at a problem got me back on track. otherwise i would have an empty wallet and a non running car.
as a side note i am thinking that with all the electronic failures in this car someone must have done something like hook a battery charger up backwards or jumper cables. fried it or something. computer and a ton of sensors... something happened.
It is easy to become the victim of the previous owner(s) efforts. These cars have seen lots of time and tinkering, so nothing surprises me anymore
 
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