[gnnash]

Driving my Daytona to church yesterday, I noticed a bit of intermittant loss of power at times, particularly at higher throttle input. I ran a few errands afterward, and the problem got immensely worse, with the engine bogging down while trying to start moving through intersections. I stopped and disconnected my CTS, as I know that it is bad (I've ordered a new one from rock auto already), to see if it would solve the problem. Noticed that the temperature sensor on the throttle body was disconnected at that point, so I reconnected it as well. Made it to one more store with some serious heasitation and bogging, then eventually had to pull into a parking lot as it was obvious that I wouldn't be getting any further, and the engine eventually stalled out.

My current symptoms:
With CTS connected, engine will crank but never "catch" or fire at all (an issue I've been having at certain engine temperatures, and the reason why I disconected my CTS to try to solve the issue)

With CTS disconnected, if I let the fuel pump run its priming cycle twice, the engine will start, but then die after 5 seconds, or the first time I open the throttle.

I'm assuming this is a fuel delivery issue, either a clogged filter or bad pump. The pump did not sound like its normal self yesterday, but has a bit more of a labored growl to it. It runs for a few seconds when the key is turned as well, not the slower half to one second cycle that it runs when the system is pressurized normally.

Does this indeed sound like a fuel issue? Codes are 15 (speed sensor, a new one for me), 22 (CTS, consistent with my bad CTS and/or me disconnecting it), and 23 (Air charge temp sensor, consistent with it having been unplugged).

Unfortunately, I am out of town for work through Friday, and then next week Monday through Friday. Fortunately, they get me a rental car when I travel, but unfortunately, this means I need to plan my diagnosis for a limited amount of time next weekend, and the repair for the following weekend. This is my plan of attack:

-Replace the CTS this weekend
-Check for 12 volts at the fuel pump - determine if issue is electrical or not
-Test fuel pressure at several points in the system to determine if the issue is pump, filter or regulator
-Possibly replace the fuel pump (if determined to be bad) the following weekend.

If this turns out to be the pump, how bad is the job? I'm in Minnesota, and the the car is currently sitting in my front yard in about three inches of slushy snow (couldn't push it very far out of the way), and unfortunately has about 3/4 of a tank full of gas. Should I expect to buy new straps for the tank as well, since they are probably rusty, and can the old pump mounting hardware be reused?

Sorry for the long message, I'm trying to plan out this repair in advance since my actual repair time is so limited. As always, thanks in advance for any and all suggestions!

 

[mpgmike]

I've been able to swap out pumps without dropping the tank. You have to fanangle the heck out of it to get the old one out and new one in, but I've done it. You may find that the nuts that hold the straps up are rusted beyond removing. If like me, you may also find the retaining ring around the fuel pump access is rusted beyond removing. Spray everything with PB Blaster before you leave for your trip in hopes it cooperates next weekend. Hope this helps.

Mike

 

[Bob Lincoln]

None of this explains the code 15. That tells me that the speed sensor is defective (which can cause the driveability problems if it's intermittent); the plug/wiring is bad; or a ground is bad/intermittent.

Do the speedometer and odometer, and trip odometer, all work normally? No flakiness?

Check grounds from battery to block, battery to left fenderwell, passenger firewall to intake manifold, and ground lug from harness at driver's rear corner of block.

Fuel pump running for 2 seconds is normal. Varies slightly with vintage of car, I've noticed.

 

[gnnash]

I've been able to swap out pumps without dropping the tank. You have to fanangle the heck out of it to get the old one out and new one in, but I've done it. You may find that the nuts that hold the straps up are rusted beyond removing. If like me, you may also find the retaining ring around the fuel pump access is rusted beyond removing. Spray everything with PB Blaster before you leave for your trip in hopes it cooperates next weekend. Hope this helps.

Mike

With the rust situation I have under my car, I'm sure that it would be pretty frozen into place. Unfortunately I'm already out of town, so can't spray any penetrant, but it's good to hear it's possible to swap without dropping the tank!

None of this explains the code 15. That tells me that the speed sensor is defective (which can cause the driveability problems if it's intermittent); the plug/wiring is bad; or a ground is bad/intermittent.

Do the speedometer and odometer, and trip odometer, all work normally? No flakiness?

Check grounds from battery to block, battery to left fenderwell, passenger firewall to intake manifold, and ground lug from harness at driver's rear corner of block.

Fuel pump running for 2 seconds is normal. Varies slightly with vintage of car, I've noticed.

The code 15 is brand new for me, wasn't there two weeks ago, the last time I checked codes, and I've never seen it before. No issues at all with my odometer or speedometer that I have seen, though I do have a digi dash which would probably hide any extremely small dropouts in signal. Never had a problem with cruise control either.

I'll check the grounds as well, thanks for the tip. My fuel pump usually runs that long for me (2 seconds or so) after being shut off overnight, but typically runs for a much shorter duration when the system is still pressurized, or during a second priming cycle, leading me to suspect something.

 

[Bob Lincoln]

Duration of the pump running is not variable. It's controlled by the ECM, which closes the ASD relay and opens it after a fixed time interval of not seeing a distributor pickup signal. I don't know what you're experiencing.

 

[gnnash]

Duration of the pump running is not variable. It's controlled by the ECM, which closes the ASD relay and opens it after a fixed time interval of not seeing a distributor pickup signal. I don't know what you're experiencing.

Interesting... perhaps that part is all in my head with the change in fuel pump sound.

 

[gnnash]

I think I realized why I have the speed sensor code after reading the conditions under which it is set. I have an occasional high idle condition, which showed up again in the three or so days before this all happened. Sitting at a stop sign with a 2000 RPM idle for more than seven seconds would have triggered the code, since the computer wouldn't have had a speed signal, but would have had an engine speed over 950 RPM above target.

I'll still check grounds when I get home anyway.

 

[Bob Lincoln]

You may have a vacuum leak. Check at the throttle body gaskets and all vacuum hoses.

 

[gnnash]

I'll add that to the list. I'll probably be borrowing a fuel gauge from an auto parts store, hopefully it'll double as a vacuum gauge as well. I'll give the lines a good look over, too.

Looking like snow on Saturday, and the car's outside...

 

[Bob Lincoln]

You won't be able to connect a fuel gauge easily. This car does not have a Schrader valve as the turbos do. You'd have to cut into a rubber fuel hose somewhere and rig up a T fitting.

 

[gnnash]

I understand that, but I'd like to be able to rule out the fuel pump and regulator as possible problems, or find out if one really is the culprit.

 

[Bob Lincoln]

Unbolt the fuel filter from the chassis, disconnect the output hose and aim it into a safe container. Wear goggles and gloves, and jumper the fuel pump relay with key on, to get the pump running continuously. If you see regular spurts of gas coming out, the pump is OK.

 

[gnnash]

Unbolt the fuel filter from the chassis, disconnect the output hose and aim it into a safe container. Wear goggles and gloves, and jumper the fuel pump relay with key on, to get the pump running continuously. If you see regular spurts of gas coming out, the pump is OK.

Would it be possible that it isn't able to supply enough pressure though? And it should be regular spurts and not a continuous stream?

 

[Bob Lincoln]

It should be regular spurts. If you get that, it should at least start and idle.

 

[gnnash]

Replaced the CTS, no start. Unplugged MAP sensor, no start. Didn't get to check grounds, but looked for any obvious vacuum leaks.

The car will start and run with starting fluid. Tried to test fuel pressure, but autozone's kit had an adapter with a plugged schraeder valve, so I couldn't test for sure. Fuel right out of pump comes out in a weak stream, no spurts...

Replaced fuel filter, it was full of black (!) fuel. Fuel from pump is clear yellow as normal. Still no starting with new filter.

I'm guessing fuel pump, and since I'm not going to be around this week again (not to mention the inhospitable weather outside), I may tow it to my local repair shop tomorrow and let them do the final diagnosis and replacement. I'm guessing ~ $500 installed for a new pump?


Also, there was never any noticable pressure when disconnecting fuel lines - only flow from gravity of what fuel was left in the lines.

 

[Bob Lincoln]

Sounds like the filter was clogged badly. Chrysler says to replace them every 5 years or 52,500 miles. The fuel pump may be worn out or the sock clogged, either one means pulling it out of the tank, so a new one is a good idea. Price will be nearly $600. I'd go with OEM and not a cheap brand like Airtex, which has a reputation for failing early. I used Bosch in my car, it was $186 for the part.

 

[gnnash]

Interesting... The filter didn't seem clogged, it flowed air quite well, and was last replaced about 20,000 miles ago. The blackness is troubling though.

Interestingly enough, looking at the back end of the pump yesterday, it appears it may have been the original! It had a sticker on it (under years of dirt and grime) that said "TBI", I can't imagine why an aftermarket pump would make that distinction, but it makes perfect sense on an assembly line. If it indeed was original and has lasted over 275,000 miles, I guess I can't be too disappointed in it failing!

I intend to let the shop know that I would like a Bosch pump, I've heard similar thngs about the cheaper tier of autozone-type pumps.

Thanks for the help!

 

[gnnash]

$415.76 installed for a new Delphi pump. Not too bad of a price for the job, I think.

Haven't been back to see the car yet, but according to my roommate, it's back and now running well.

Thanks again!

 

[Bob Lincoln]

Excellent! That's a good price for the job.

 

[John Wood]

You did very well on the original pump. Rarely will they last until 275,000. In fact I never heard of one making it that far. It could be the car was driven mostly on highways.

The fuel pump contains a DC motor with carbon brushes that do eventually wear out. The pump spins anytime the engine is running, whether or not the car is moving, so a car that is driven in mostly city (stop and go traffic) will usually have a pump fail at lower mileage than a vehicle that is always moving down the highway.