82 intermittent non start

[gudtimer41]

After running well any number of times, my previously reliable 82 refused to fire up. Starter works well, but the engine like there was no fuel getting to it as it spun very loosely. A very good mechanic went over it with a fine toothed comb and the fuel injection , electrical ignition etc. all checked out as good. Just as he was giving up, it started. No rhyme or reason. I drove it again and it worked well through several turn off and restarts and then pulled the same thing again. Had it towed home and it sat in the garage for a couple of weeks. I went out there and thought, what the hell, why not try it? Yup, it started up again, as it did for another couple of trys. I did loosen up the gas cap thinking of negative pressure earlier but no go there. All the fuses look good. Fuel pump connections seem solid, and the pump was replaced about 5,000 miles ago. Bad pump? as all other systems seem good? Help!!!

[micbrody]

I had similar problems. Went through every system. Last thing I checked was pressure in fuel rail. It was all over the place . After more diagnostics , I concluded that pump could pump fuel , but not reliably or consistently pressure ( either pump mechanism failing or internal pump check valve bad). I replaced with $70 Bosch pump (purchased on Amazon ). Solved starting problem

[aevansgatech]

micbrody, out of curiosity did you notice that the "weak" pump was noisy? or that the new one was noticeably quieter?

I don't have starting/fuel issues yet, but in my opinion my fuel pump is pretty loud compared to others. I really notice it when the key is in 'run'. I'm wondering if it's just a matter of time before I have an issue.

[KevAndAndi]

micbrody, out of curiosity did you notice that the "weak" pump was noisy? or that the new one was noticeably quieter?

I don't have starting/fuel issues yet, but in my opinion my fuel pump is pretty loud compared to others. I really notice it when the key is in 'run'. I'm wondering if it's just a matter of time before I have an issue.

Just a matter of time.

My OE Bosch fuel pump suddenly got loud soon after I bought the car. I replaced it with a Facet that is quiet. The Bosch was nearing the end of its life. Noisy is not good.

Does your fuel pump start running before you start the engine?

[micbrody]

aevansgatech,

When I bought car about 2 yrs ago, pump was noisy. High pitched whining. I thought it was normal because a previous spider I had tested also had whining pump; and there many messages about special mount to decrease noise.
When i installed new pump, it was completely silent (at least from driver position).

[KevAndAndi]

Another thing to keep in mind is that trash in the fuel system can ruin a newly-replaced fuel pump and cause fuel delivery problems. If you don't put a fuel strainer upstream of the fuel pump, you're asking for trouble.

[courtenay]

I think you have to be very careful to ensure that if you put a fuel filter between the tank and the pump that you check/change it frequently. The pump itself is cooled by the fuel running through it and if the filter ahead of it clogs up and starves the pump of fuel it will burn out.

[aevansgatech]

micbrody, out of curiosity did you notice that the "weak" pump was noisy? or that the new one was noticeably quieter?

I don't have starting/fuel issues yet, but in my opinion my fuel pump is pretty loud compared to others. I really notice it when the key is in 'run'. I'm wondering if it's just a matter of time before I have an issue.

Just a matter of time.

My OE Bosch fuel pump suddenly got loud soon after I bought the car. I replaced it with a Facet that is quiet. The Bosch was nearing the end of its life. Noisy is not good.

Does your fuel pump start running before you start the engine?

Thanks guys, I'll bump this up on the priority list.

Fuel pump will run with the key in position (1/2). No issues starting or anything, but it is definitely audible from inside or outside of the car

[KevAndAndi]

I think you have to be very careful to ensure that if you put a fuel filter between the tank and the pump that you check/change it frequently. The pump itself is cooled by the fuel running through it and if the filter ahead of it clogs up and starves the pump of fuel it will burn out.

Good point. When I put in the fuel strainer (actually not a filter, per se), I made a mental note to check it down the road. I had seen some rust flakes in the fuel tank and tried to remove them with the tank in place, to no avail. I decided to let the strainer do the work for the large particles and the filter for the small particles. So far, no problem.

On the one hand, lack of an upstream strainer can ruin a new fuel pump. On the other hand, a clogged upstream strainer can ruin a new fuel pump. (Though, in the latter case, wouldn't you get a warning by the symptoms of a fuel-starved engine? How long would it take for the pump to burn out in such a situation?)

[KevAndAndi]

micbrody, out of curiosity did you notice that the "weak" pump was noisy? or that the new one was noticeably quieter?

I don't have starting/fuel issues yet, but in my opinion my fuel pump is pretty loud compared to others. I really notice it when the key is in 'run'. I'm wondering if it's just a matter of time before I have an issue.

Just a matter of time.

My OE Bosch fuel pump suddenly got loud soon after I bought the car. I replaced it with a Facet that is quiet. The Bosch was nearing the end of its life. Noisy is not good.

Does your fuel pump start running before you start the engine?

Thanks guys, I'll bump this up on the priority list.

Fuel pump will run with the key in position (1/2). No issues starting or anything, but it is definitely audible from inside or outside of the car

As you may know, it is not normal, nor safe, for the fuel pump to run in the pre-start position. Many folks - my car's PO included - live with this situation, though. There are many posts on the subject. The symptom often means that the fuel pump actuation lever in the air flow meter has been bent, intentionally or not.

I am broken record in this regard, but: My advice to anyone with an FI Spider whose AFM is original and has not been professionally rebuilt/serviced is to send it to an outfit such as Fuel Injection Corp. and have them replace the electronics, blast and paint it, and test it. Best $200 I ever spent on the car. Transformed it from a rich-smelling, stalling PITA to a well-running car. The AFM's air flap gets bent, the electrical wiper track inside gets worn, and the air bypass screw is a playground for mischief by PO's.

[lglade]

Thanks for the reference Kevin. I've seen you say that before and I plan to follow your lead this winter when the car is tucked away. My fuel injection seems to be fine right now, but the AFM is bound to benefit from some light maintenance and re-calibration.

[aevansgatech]

Thanks for the information. I thought that was normal operation

I did just swap in a new Bosch fuel pump and fear I may have burned it up. It seemed simple enough, so I just put the "large lead" wire to the large post of the new pump and the "smaller lead" wire to the small post. I attempted to start and the engine turns over but won't fire. After trying few times, now I don't hear the fuel pump turn on...

I'm too frustrated to take it back apart today, so any tips would be helpful. I know running it dry will burn it up, but fuel should definitely be available from the tank because it dripped while I installed the line to the pump.

[KevAndAndi]

Thanks for the reference Kevin. I've seen you say that before..."

Like I said, I'm a broken record!

The AFM is the heart of the FI system, so if it's not working right, the engine is never going to be running right.

Someone (I think it was Mark) said that ideally, the AFM's bypass screw should be adjusted on the car when it's running rather than "in the lab", so to speak. This may be true, but it's probably not easy to find a mechanic qualified to make those adjustments. Fuel Injection Corp. says their process is:

1. AFM's are stripped to the component level.
2. All parts, mechanical and electrical are tested to meet OEM specifications.
3. Unit is assembled using known good parts.
4. Simulator then runs AFM through all phases of operation.
5. Spring tension, wiper position and CO screw are calibrated to OEM specification.
6. Once the AFM meets all OEM specifications the unit is sealed and packaged.

I trust that their simulator, while not my actual car, is capable of getting the calibrations close to OEM specs. All I know for sure is that my engine is running pretty close to perfect.

[KevAndAndi]

Thanks for the information. I thought that was normal operation

I did just swap in a new Bosch fuel pump and fear I may have burned it up. It seemed simple enough, so I just put the "large lead" wire to the large post of the new pump and the "smaller lead" wire to the small post. I attempted to start and the engine turns over but won't fire. After trying few times, now I don't hear the fuel pump turn on...

I'm too frustrated to take it back apart today, so any tips would be helpful. I know running it dry will burn it up, but fuel should definitely be available from the tank because it dripped while I installed the line to the pump.

That is such a drag; sorry to hear. I know one potential error is wiring the FP backwards which causes it to run backwards, but I don't think that should cause it to burn out.

You might consider figuring out why the FP is running in the pre-start position before you install a new FP. As I said, one possibility is that the actuation arm in the AFM is bent. Is it a bit of a PITA to get the cover off the AFM, though. There are other possible causes, which you can find by searching the archives. For example, some POs change the wiring so the FP runs in the pre-start position. Their "cure" is worse than whatever the disease was.

[aevansgatech]

Bingo, nailed it on the wiring. Just another example of the many small and counter-intuitive things that can happen during auto repair! One would think that if the original pump has a large connector and a small connector, that the new pump would reuse large spade -> large ring connector and small spade -> small ring. I did, in fact, have to switch them up

This time I gave it a quick test run into a jar before connecting the pump to the filter to confirm it was pumping fuel.