Unreliable

[Fiddledeede2]

My very reliable 94 ATX SHO has failed to start for me twice in the last 10 days. The first time, I went to a movie, came out and it would turn over but not start. I tried several times with no luck. I switched off the AC and Radio, waited 5 mins and tried again - it started. No problems since then until tonight (10 days later). Same thing - went to dinner for 90 mins came out and would not start. This time I waited 5 mins put my foot flat on the gas- no luck. I switched off the radio and AC waited 5 mins and it started.

The battery is about a 11 months old and I also got a new alternator 11 months ago.

I suspect it is a fuel problem. Any ideas.

 

[TYSHO]

When you press the gas to the floor, while starting, it will cut the injectors off. With that said, you will never be able to start the car until you let off the gas, while cranking.

It is possible that the return valve on your fuel pump is bad. When that's bad, it dumps all of the fuel back in the tank, not allowing enough pressure at the fuel rails. If this is the case, you will have better luck priming the pump. To do that, turn the ignition into the "on" position, where you hear the fuel pump come on, then turn it back. Repeat that at least 3 times, and start her up...she should start much easier.

A way to tell if that valve is bad is to put a guage on the shrader valve, located on one of the fuel rails, then turn the key to the "on" position. If you get a quick bump of pressure, then it falls back to zero very quickly, split second or a couple, then that's more and likely the problem.

 

[shoteen95]

good advice, i hear a cheap tire pressure gauge works well..just dont expect it to last too long.

Any odd noises coming from the tank? is it still on the original fuel pump?

 

[sdpatt]

The drop in pressure after priming would be the result of a leaking discharge check valve on the fuel pump itself or the pressure regulator on the fuel rails rather than the fuel return line check valve.

 

[Rockledge]

Regarding fuel delivery, next time it happens pull the vacuum hose of the FPR and check for fuel.

Also, Let us know what the codes are after you pull them:

http://www.shophoenixproject.com/eec/eec.htm

 

[jelloslug]

You should check 2 things:

1) Turn the switch to RUN but not start and listen to the fuel pump prime. How does it sound? Switch the car from OFF to RUN several time and see if the pump changes pitch when the system is pressurized.

2) When the car is cranking and won't start look at the tach. If the tach is not moving while cranking you have a bad CID. The CID (cylinder identification sensor) tells the ECU where the engine is at (rotation wise) while cranking. It also generates the tach signal.

 

[Fiddledeede2]

Thanks for all your suggestions. It has not happened again since my last post so I have not been able to check the vaccum hose or the tach or the pressure. There are no strange sounds coming from the tank and the fuel pump sounds fine. I did however pull the codes:

With KOEO I get 111 for current but stored codes are
124 (M) TP voltage was higher than expected - Fuel control
212 (M) Ignition TACH signal was erratic (module/wiring) or SPOUT circuit fault - Ignition Systems
214 (M) Error in Cylinder ID (CID) circuit or signal - Ignition Systems

With KOER test I get 111

Seems like it might be the CID. I'll check the tach (as jelloslug suggested), the next time it fails.

What do the rest of you think based on these codes?

 

[Howdy_Doody]

6 replies and no one has suggested a Crankshaft Position Sensor? About the most commen cause of no starts/misfiring on a SHO. Had mine do exactly the same thing as yours (I was parked outside a ********** and would have been in deep sh*t if it hadn't got it started). Do some searches on this website and you'll find everything you need. A maintenace item usually done at 60K tuneup.

 

[jedhead]

When my CPS failed, I still showed 400rpm when I was cranking the engine. However when I hooked up the timing light I had no spark. I was very unhappy because I replace a perfectly working CPS for this one that failed 6 months later as a preventative measure when I did the 60k. I plan to leave this one alone when I do the 60k again, but I am sure Murphy will strike me again.

Bob

 

[Fiddledeede2]

I was reading through posts on CPS as Howdy-Doody suggested and I noticed that some of them referred to oil leaking onto the CPS or CID causing problems. I have a slow oil leak (needs oil every 3 months or so) that I haven't investigated. Could they be related.

 

[Sexymeatball]

When you press the gas to the floor, while starting, it will cut the injectors off. With that said, you will never be able to start the car until you let off the gas, while cranking.

I guess my car didnt get the memo. I'll be sure to let it know not to start if I have my pedal on the floor from now on.

 

[Fiddledeede2]

I think it is probably the CID. I checked the last time it failed to start and there was no tach signal. I have two questions.

1) I believe that the CID is relatavile easy to install (although the CPS is not). Can anyone point me to some installation instructions or at least give me an idea where to find it.

2) I have another problem that happens sometimes when I take off from a start. About the time it should change into 2nd, it kind of stutters. At first I thought it was a gear problem, but now I think it is a fuel delivery or tach signal problem. Could a bad CID affect that too.

Thanks

 

[NiNeTy Fo SHO]

The CID is located on the engine directly across from the power steering reservoir (dont think that is spelled right) on the passenger side of the engine. There are 2 screws holding the CID in place. It is about where the rear valve cover is on the passenger side. If you buy a new one, you will see what its like and be able to find the one in your car mucho easier.

I would doubt that the CID would affect the transmission shifting. Some would say that is your tranny starting to go out on you.

 

[voogru]

fiddledeedee I had the same thing happen to my 91, engine stuttering and I did a code check and it seemed to be the cam position sensor, I changed it and all is fine again, cheap too

 

[Fiddledeede2]

Voogru,
I am going to replace the CID. I could replace the CPS at the same time. Isn't the CPS really difficult to install and are there any instructions anywhere. I replaced the CPS 4 years ago at 64K (now at 90K). Does it seem reasonable that it would fail after about 30K.

 

[Fiddledeede2]

I found an Ac Delco CID at ROCKAUTO for $33 and a Wells CPS at World Auto Parts for $ 44.40. Anyone know anything good or bad about Wells or AC Delco parts for the SHO.

 

[NiNeTy Fo SHO]

I got the Wells from advance auto or AZ for like ~$37. It was the recommended part to buy.