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no starting...possible fuel pump or relay


Go to solution Solved by zman1858,

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1998 boxster 108,000 miles...cranked up and then die. Codes are P1237,P1238, P1239,P1240,P1241,P1242(this is all 6 cylinders have an open circuit). Other codes P1124 and P1126(bank 1 and 2 too lean). And of course, P0410, PP1128 and P1411. I have an o-ring with a slight leak on one injector(been leaking for 1 year, I should have repaired by now, I know). Bottom line...the car turns over fine but no firing off. I thinking relay or fuel pump. all regular fuses checked out ok and even checked the one on the brain under the seat. The battery is 6 months old(someone will ask, always do). There is gas in the tank. How can check the relay and pump, thanks

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1998 boxster 108,000 miles...cranked up and then die. Codes are P1237,P1238, P1239,P1240,P1241,P1242(this is all 6 cylinders have an open circuit). Other codes P1124 and P1126(bank 1 and 2 too lean). And of course, P0410, PP1128 and P1411. I have an o-ring with a slight leak on one injector(been leaking for 1 year, I should have repaired by now, I know). Bottom line...the car turns over fine but no firing off. I thinking relay or fuel pump. all regular fuses checked out ok and even checked the one on the brain under the seat. The battery is 6 months old(someone will ask, always do). There is gas in the tank. How can check the relay and pump, thanks

Can also be the crank postion sensor, which causes the DME to shut off the fuel pump.

You can pull the fuel pump relay and rig a bypass jumer wire to test the circuit without the relay in place (do a search, has been written up before).

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1. Connect ohmmeter connector part to rpm/crankshaft position sensor, pins 1 and 2.

Display at 20 °C: 0.8 – 1.0 k Ohms

2. Connect ohmmeter connector part to rpm/crankshaft position sensor, pins 1 and 3.Display: infinite ohms

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1. Connect ohmmeter connector part to rpm/crankshaft position sensor, pins 1 and 2.

Display at 20 °C: 0.8 – 1.0 k Ohms

2. Connect ohmmeter connector part to rpm/crankshaft position sensor, pins 1 and 3.Display: infinite ohms

The man is getting good at this............................................ :thumbup:

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One more thing I thought of...Before my car died. I cranked it up, back up, place in it 1st and only got about 3 feet and then it just suddenly shut off. Engine turns over but won't fire off. Thanks for any help.

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I hate to ask, where is the rpm/crankshaft position sensor located, thanks

Side of the bell housing, the sensor reads teeth the on the back of the flywheel to determine engine rotational position.

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OK...I jumper the relay and could hear a humming from behind the seats before I turned the key. I turned the key in the on position and didn't hear anything near the fuel pump and listened thur the tank with the gas cap off. Tried to crank the car and a no go. Would it be a good bet to go with the fuel pump. Thanks in advance.

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It wouldn't be a good bet to make a determination without doing further due dilligence. If the CPS was bad, the fuel pump wouldn't be activated -- no matter if you replace it or not. In other words, just because it's not being activated doesn't mean it's bad and is what's causing the problem. Better to troubleshoot this one properly rather than just throwing parts at it.

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OK...I jumper the relay and could hear a humming from behind the seats before I turned the key. I turned the key in the on position and didn't hear anything near the fuel pump and listened thur the tank with the gas cap off. Tried to crank the car and a no go. Would it be a good bet to go with the fuel pump. Thanks in advance.

I am a bit perplexed by "a humming behind the seats" as the fuel pump is in the fuel tank, ahead of the windshield on a 986. Are you sure you jumpered the relay correctly? Silver_TT is also spot on that you could still have a failing CPS and should be checking that as well before buying parts.

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I don't mind easter-egging a little. If I'm crawling under the car, I'm changing the crank sensor. The relay cost me $10.00. What would be a route to go if it's not the sensor. Any thoughts would be appreciated. Thanks

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If that's the case, expect to pay about $100 for the CPS, which may or may not be the issue, but could be both quickly and easily tested and eliminated without the expense...............

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Let me start by saying that I don't mind easter egging as long as it's not too much $$$. If you really want to know why...it's because I have a disability and can't crawl under the car too much. The car is getting some age on it and it may prevent something that may be waiting to happen. I refuse to ask someone to do it for me if I feel I can do it(and enjoy the pride of doing it myself). With that being said, the relay and crankshaft sensor has been changed. Sensor wasn't too bad. I will like to write up a how-to for novices without the tech words. The car still will not crank....what everyone's thought on the fuel pump? I can't think of anything else. Thanks for any replies.

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Another thought...because of the codes p1237, p1238,p1239,p1240,p1241 and p1242 injector circuit open cylinder 1-6. I starting to think electrical issue. Thoughts ???? I know I didn't have 6 injectors die at the same time....thanks

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Another thought...because of the codes p1237, p1238,p1239,p1240,p1241 and p1242 injector circuit open cylinder 1-6. I starting to think electrical issue. Thoughts ???? I know I didn't have 6 injectors die at the same time....thanks

All these codes indicate an interruption of the signal from the DME to the injector coils. OEM manual procedure is to check the individual injector wire harness from the injector to the DME using the infamous 9616 pin out box, looking are resistance and voltage.

While this could be a wiring issue (like rodent damage), because all the injectors are out, it may also be a DME issue.

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Another thought...because of the codes p1237, p1238,p1239,p1240,p1241 and p1242 injector circuit open cylinder 1-6. I starting to think electrical issue. Thoughts ???? I know I didn't have 6 injectors die at the same time....thanks

All these codes indicate an interruption of the signal from the DME to the injector coils. OEM manual procedure is to check the individual injector wire harness from the injector to the DME using the infamous 9616 pin out box, looking are resistance and voltage.

While this could be a wiring issue (like rodent damage), because all the injectors are out, it may also be a DME issue.

you would rule out the fuel pump correct..thanks for the quick reply

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Another thought...because of the codes p1237, p1238,p1239,p1240,p1241 and p1242 injector circuit open cylinder 1-6. I starting to think electrical issue. Thoughts ???? I know I didn't have 6 injectors die at the same time....thanks

All these codes indicate an interruption of the signal from the DME to the injector coils. OEM manual procedure is to check the individual injector wire harness from the injector to the DME using the infamous 9616 pin out box, looking are resistance and voltage.

While this could be a wiring issue (like rodent damage), because all the injectors are out, it may also be a DME issue.

you would rule out the fuel pump correct..thanks for the quick reply

A fuel pump failure is not going to cause a communications issue with all six injectors. You can quickly rule out the fuel pump as an additional problem candidate by connecting an appropriate fuel pressure test gauge to the test port on the fuel rail, if it generates pressure and delivery rates within specs, there is nothing wrong with it.

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Have you cleared the fault codes? Which ones return? You mention in post 16 that the car will still not crank... is this a typo? It cranks but just won't flash up, correct?

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  • 2 weeks later...

The dealer said the DME is shot. Not really believing that. First he said the fuel pump, I told him I just changed it. Then he said the DME. Feel like I'm getting ripped off,it took 2 weeks to get this answer. Question, can a used DME from LA Dismantlers get re-programmed for a 1998 Boxster. I have all the codes from the brain under the driver's seat and the car key. LA told me $700.00 for DME or $1,500.00 for DME, unit under the seat and key. If dealer won't or can't program DME, will the $1,500.00 set up need any programming or will it plug and play since all 3 pieces came from the same car. Thanks

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The dealer said the DME is shot. Not really believing that. First he said the fuel pump, I told him I just changed it. Then he said the DME. Feel like I'm getting ripped off,it took 2 weeks to get this answer. Question, can a used DME from LA Dismantlers get re-programmed for a 1998 Boxster. I have all the codes from the brain under the driver's seat and the car key. LA told me $700.00 for DME or $1,500.00 for DME, unit under the seat and key. If dealer won't or can't program DME, will the $1,500.00 set up need any programming or will it plug and play since all 3 pieces came from the same car. Thanks

The new DME will have to be coded with the IPAS code data from your current unit to work correctly with the other components in the car; that entails either a PST II or PIWIS unit and someone that knows what they are doing. You will also loose your current total mileage as that is specifically not changeable. Going with everything from another car would skip the programing, but you would still have the mileage issue and you would have to change the key pills over to your keys. I would think that just swapping the DME would be the most economical route.

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Well...car is back running. After 2 weeks, dealer said fuel pump and I told him just changed it. Then without a breath, he said DME and $6,000.00. Told him I thought they rarely go out. Then all of a sudden, 2 hours later, he calls and says there is a broken wire under the top intake. Will be 6 hours labor $750.00. He called me within 3 hours and said it was done. Picked up the car and as soon as I sat in it, realize the seat wasn't bolted (bolts were in the center console). I feel I got ripped off and just decided that I'll re-bolt the seat. I only hope I didn't pay $750.00 for a DME relay. On the plus side, he did program my spare key for free from 3 years ago when I forget to give it to them when the immoblizer drown. Until next time....thanks for all the input !!!!

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this is your "Best Answer."

Another thought...because of the codes p1237, p1238,p1239,p1240,p1241 and p1242 injector circuit open cylinder 1-6. I starting to think electrical issue. Thoughts ???? I know I didn't have 6 injectors die at the same time....thanks

All these codes indicate an interruption of the signal from the DME to the injector coils. OEM manual procedure is to check the individual injector wire harness from the injector to the DME using the infamous 9616 pin out box, looking are resistance and voltage.

While this could be a wiring issue (like rodent damage), because all the injectors are out, it may also be a DME issue.

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