89 SHO wouldn't start; started fine 4 hours later

[Raven SHO]

Hi, all. So my "new" 89 SHO with 145k miles has been running fine since I acquired it in late August. This week, On Tuesday evening, I decided to check the air filter; looked brand new... But getting the cover back on was difficult. Next day it started just fine 3 times, then, trying to leave after a doc's appt to go back to work, I tried to start it, and it cranked just fine, but didn't catch. Just sort of Grrwwwffftt... Did that 5 times, waited 5 minutes, tried it four more times, and gave up. Had my wife come get me (grumbling), went back to meet a tow truck there 4 hours later... Started right up. 4 times. Haven't tried to drive it since. Any ideas?

 

[SHOdded]

Air leaks? Unplugged MAF sensor? Maybe you can post some pics of the area of the engine bay as it stands now, and any codes that you pull.

 

[luigisho]

Pull the codes. First guess is crank or cam sensor. Crank sensor is notorious for failing intermittently and then working again. If it's going bad it will strand you again.

 

[itwonder]

Next time it happens, try holding the gas pedal to the floor as you crank. It could be a crank sensor going out because the water pump is dripping onto it. Listen for the fuel pump priming when you turn the key to ON to make sure it's not a fuel problem. You should be able to hear it run for a few seconds and then stop; having the window down helps.

 

[Ujoint]

Plugged cats?

 

[sdpatt]

I am thinking of the same causes as itwonder; CPS or fuel pump. As they are near their end-of-life, they will both exhibit heat-related failures where they will function again after cooling down. How does that fuel pump sound when it primes as you turn the ignition key to ON? Does it have the same high pitched sound as usual? Was the fuel tank level low enough to leave the pump motor uncovered by the cooling effects of the fuel? The CPS will usually set an error code.

 

[ISHOU]

I am thinking of the same causes as itwonder; CPS or fuel pump. As they are near their end-of-life, they will both exhibit heat-related failures where they will function again after cooling down. How does that fuel pump sound when it primes as you turn the ignition key to ON? Does it have the same high pitched sound as usual? Was the fuel tank level low enough to leave the pump motor uncovered by the cooling effects of the fuel? The CPS will usually set an error code.

Sounds like crank sensor to me as well. And not to hijack the thread but great to see Scott reply to a post. Haven't seen you on here in quite some time. Thought of you a few weeks back when my 94 went over 200,000 and knew I had nothing on you.

 

[cali+Mocasho+]

Hi, all. So my "new" 89 SHO with 145k miles has been running fine since I acquired it in late August. This week, On Tuesday evening, I decided to check the air filter; looked brand new... But getting the cover back on was difficult. Next day it started just fine 3 times, then, trying to leave after a doc's appt to go back to work, I tried to start it, and it cranked just fine, but didn't catch. Just sort of Grrwwwffftt... Did that 5 times, waited 5 minutes, tried it four more times, and gave up. Had my wife come get me (grumbling), went back to meet a tow truck there 4 hours later... Started right up. 4 times. Haven't tried to drive it since. Any ideas?

i had the same symptoms turned out to be cam sensor sending erratic signal to the ignition system. try pulling the connector off. it s right above the power steering pump.

 

[Raven SHO]

Just checking these again... Hasn't happened again, but after driving her for 1 hours two weeks ago (cruising at slow speed to check out Christmas lights with my 8 year old) there was a definite burning smell afterwards.

I ran the codes 3 weeks after this happened and got:
Running:
No active codes, just stored codes.
Stored codes: 13, 77.
Also, cylinder test was OK

Key on Engine Off:
11 - system checks ok
Stored codes:
22, 95.
95 implies that one possibility is a bad fuel pump ground...

Thanks, Mike

 

[cali+Mocasho+]

Just checking these again... Hasn't happened again, but after driving her for 1 hours two weeks ago (cruising at slow speed to check out Christmas lights with my 8 year old) there was a definite burning smell afterwards.

I ran the codes 3 weeks after this happened and got:
Running:
No active codes, just stored codes.
Stored codes: 13, 77.
Also, cylinder test was OK

Key on Engine Off:
11 - system checks ok
Stored codes:
22, 95.
95 implies that one possibility is a bad fuel pump ground...

Thanks, Mike

what do you think its burning off of? the right cat? if so the few possibilitys are power steering leak or oil seeping its way out. Have you took the time to look for any leaks?

 

[rubydist]

13 = cannot control idle during self-test, suspect iac
77 = brief WOT not sensed during self-test, typically operator error
22 = BP out of self-test range
95 = fuel pump secondary circuit failure

on the 89 cars, the 95 code is sometimes important but many times not, since it also gets set any time the engine stalls. I would not focus on that at this time.

I would get a new BP sensor, install that and reset codes, then see what happens.

If you have a problem with idle surging, then I would replace the iac too. If not, I would be looking for a significant vacuum leak on the intake.