Severe problem, don't know what to do

[philw349]

My SHO has been pretty much out for the count for about a month. I haven't been able to fix what is ailing it. I replaced the fuel pump for a 190lph model. Then when that didn't fix it, I went back into the tank and threw out the pulse dampener and replaced it with the hose that came with the pump, as well as replaced the duck beak valve (was waiting for the part). Still didn't work.

I can get it to start by flooring it until it reaches a stable rpm. It seems to build up rpms like a locomotive. It has no liveliness at all until it hits 4000rpm, but it's a struggle to get there in neutral. When I let off it idles alright (which is an improvement), but then I just have to tap the gas pedal after that, and it immediately dies out. It's strange. The presence of fuel pressure seems to indicate the fuel pump is working alright. It hits about 42 psi primed, and then dies down to about 35 in 10 seconds or so. I couldn't run tests with it running because the crappy autozone pressure gauge broke (after 3 uses).

I took it to Pep boys out of desperation. They told me that everything they could measure was in spec, including the fuel pressure. Although I couldn't get ahold of the guy who did the actual measurements. Then they referred me to the dealership. I'm just wondering what else it could be. But then that could be a lot I suppose. Last time I took codes there were none. Maybe there will be some now in the more deteriorated state. The last thing the tech told me was to get the exhaust checked to see if its blocked, so I've come in a complete circle.

I'm all for paying the dealership for a diagnostic and then fixing stuff myself. That's pretty much my next step unless someone has better ideas. It's just frustrating dropping the tank twice and then having to get it towed. The joys of SHO ownership.

I must say I love the new site though!

 

[autobahnsho]

If you have fuel pressure over 30psi, I think you should be good.

Have you checked the engine computer codes yet?? See shotimes.com under "maintenance" for easy instructions how to do it.

These engines are also picky about air, maybe your exhaust is having an issue, or an air sensor is not acting right.

Run the codes and get back with us.

Good luck!

 

[SHOTIME]

do you smell gas? that would lead you to believe the injectors are leaking at the O rings.

next step pull the intake and remove the pulse dampener and the fuel pressure regulator. the two pieces that thread into the rails on the passanger side.

see if there is any debris and clean them.

 

[bradman]

I've had the symptoms you describe. When I ran the codes I had an O2 sensor indicating lean and the ECT sensor was out of range (cold). I replaced both O2's and the ECT at the same time, and the car ran great. I'm not sure which was the problem, or it could have been a combination of both since both probems could cause the car to run rich. The EEC was just dumping in WAY more fuel than the car could handle, especially when you hit the throttle.

You should definitely run the codes.

 

[philw349]

Interesting suggestion. Too much fuel.. I'll certainly keep that in mind to get checked on. As well as for fuel injectors and fuel rail blockages. Since I've spent too much time on it already, Ford has my car and they'll be looking into those possiblities in their diagnostic.

 

[Mike Kopstain]

There are two things I would look to, actually three.

The first is your codes. Run them and see what you get.

The other two are the Mass AirFlow Sensor and the throttle position sensor.

In the case of the MAF, if the computer can not see how much air is entering, or the MAF is indicating a low voltage at all rpms/ loads, then you are essentially leaning out when opening the throttle. Conversly, if it is reading too high of a voltage it will flood the motor all the time. The reason it would slowly find an idle and slowly rev would be because the computer is compensating for the bad signal with information from the oxygen sensors. It's easy to see if this is your problem; simply unplug the MAF and drive the car around. If it drives better, you found your problem. If not, look elsewhere.

In the case of the throttle position sensor, the computer is not able to determine load and has to compensate for that with information from the MAF and the oxygen sensors. To determine if this is your problem, probe the TPS and make sure it's specs are as follows:

Fully Closed: 1.00 volts or slightly under
Fully Open: 5.00 volts or slightly under
Also, as you are reading the voltage, slowly open and close the throttle to verify the contacts in the TPS do not have any flat spots.

 

[philw349]

Got a call from Ford. They said that the fuel pressure is good. They think the vehicle is "jumping timing" which is causing it to act so poorly. They also think this can lead to a rich condition. I had the timing belt done about 50k ago, but I suppose it's possible. Sound reasonable? he wants to confirm it first by opening the timing cover.

 

[F-22 Raptor SHO]

I differ back to what the others have said and find out what the car is trying to tell you via "the codes". Being the dealer has the car now, they should have run them first thing to figure out what direction to go.

I knowing your FP was fine would have led me to believe something else was amiss with the car, but again, the codes are what would tell us what to do next.

I'm always skeptical of what dealers say unless I have a trusting relationship with them.

 

[bradman]

I second what F-22 said. You should ask the Ford tech exactly what codes came up when they did the diagnostic. You could let them check the timing belt, but if it turns out to be a bad diagnosis, then you shouldn't have to pay for it.

 

[philw349]

Well they said one of the timing belt pullies was, broken. And also something like a pulley key, or something with the word "key" in it. The belt also had some edges worn off as a result of slipping. He said this was causing the timing to jump and the symptoms I had. I'm going to have him save me the belt to look at, sounds kinda wierd. The key cost a few dollars, he didn't have a quote for the pulley. I've already put good money towards the diagnostic and it's all apart so I told him to go ahead and fix it. (shrug).

 

[masho95]

Well they said one of the timing belt pullies was, broken. And also something like a pulley key, or something with the word "key" in it. The belt also had some edges worn off as a result of slipping. He said this was causing the timing to jump and the symptoms I had. I'm going to have him save me the belt to look at, sounds kinda wierd. The key cost a few dollars, he didn't have a quote for the pulley. I've already put good money towards the diagnostic and it's all apart so I told him to go ahead and fix it. (shrug).

There is no timing belt pulley unless they were refering to the timing belt tensioner. And the only thing that makes sense with the word "key" in it is the crankshaft pulley which has a keyway on it that mounts on the crankshaft. If the crank bolt wasn't tightened to spec it leads to a condition called "crank cancer". Which is when the crankshaft pulley hammers on the crankshaft key and eventually gets worn. Once the keyway is worn it will throw your timing off as it wobbles back and forth on the crankshaft key. This could have been what was causing your SHO to run so horrible.

 

[philw349]

Yikes, crank cancer. Who knew. At least they didn't offer to replace the crank, that would've scared me.. It makes sense now after reading about it on SHOtimes. The symptoms were as he described, steady loss of power over time until it will hardly run at all..

Good call on that, don't wanna get my hopes totally up, but it looks like Ford knew what they were talking about.

I guess now is a good time to post a link for new SHOwners so they dont run into the same trouble.

Crank cancer prevention