So last night I was coming home from work, not hot ******* or anything weird. Stopped at a stop sign, looked both ways, gave it a tiny crack of throttle (in a 25 mph zone) and almost nothing. Had the radio on so I didn't hear the engine and thought it was the transmission slipping. Killed the radio and noticed the engine running rough. Tried to accelerate and it just ran more rough. Shut it down and walked home.

Three hours later went back and tried it again, no dice; barely run at idle, give it a tiny bit of throttle just makes thing worse. Then it won't even run roughly at idle. Towed it home thinking timing chain and dead motor.

20ish hours later, I was gonna try it again and see if both exhaust manifolds would get hot (thinking exhaust cam chain). Car started right up and ran smoothly. Both exhausts hot, get in the car and drive 100 yards, ran good. Tried to go around the block and noticed it began to hesitate while applying throttle and then it would only operate at idle.

Did the throttle body test (checking to see if the butterfly movement matched the pedal movement and was smooth across the range) and it looked ok. Won't even idle roughly now. I'll try it again tomorrow, but anybody have suggestions on how to proceed? I need a code reader for this car, any suggestions?

 

Sounds like fuel filter or the fuel pump itself....as for a reader, the most popular on site here seems to be the ELM327 (I have it also), if your using a smartphone that is. There's a thread for it actually, just do a search.

 

What year, what model. How close to CF BMW do you live?

Fuel pump, fuel filter, disconnected or dirty MAF. Need the codes. Advance Auto will read them for you.

Best local independent is Abacus Racing on Baker Road near the ORF

 

Add a vote for the MAF, had an issue with mine and that's how it would barely run. Easy test, unplug the MAF and see if it starts and runs. If it does (it'll be in restricted performance but should idle and move fine up til 3k RPM), it's a good indicator.

 

Hi Seadawg,

Welcome to the Jaguar Forums. It's great to have you with us.

You've received some great suggestions so far. Are there any other possibly relevant details? For example, had you purchased gasoline recently that might have been contaminated? Was it raining? Had you been through a car wash?

Cheers,

Don

 

+1 on Abacus; I went there and told them "my fuel pump is shot, please replace it" (After trying to do it myself on two separate weekends, I just couldn't reach my hands back far enough to disconnect the fuel lines.)

They kept it for a week, didn't see the fuel pump as an issue, charged me a nominal troubleshooting fee even after I gave them carte blanch to swap out the pump! Seem like a real great group of folks. In the end, that issue wound up being "bore wash" which I'm sure has been discussed on this site.

The following year, (just about 10 months back) the fuel pump did croak and I had Abacus do that work.

 

Thanks for the welcome.
Refueled about three days before and had driven about 60 miles since full. I believe I got my gas where I normally do. No rain or car wash as of late.

 

This is the kind of hot tip I was looking for and exactly why I joined this forum.

So with the MAF disconnected, the car should idle and run perfectly up to 3k rpm?

P.S. '01 XJ8 ( I'll put in a sig and a profile this afternoon)

 

If it is BRG with vin ending in F35063,. . . . . sounds familiar.

Bore wash is pretty rare in an 01. Sounds like you might have an overly rich situation: if not MAF, maybe bad temperature sensor (disconnect it a the crossover pipe) or maybe a broken air tube from the filter box to the throttle body?

Need to get the codes read.

 

Just disconnected the MAF, no change. It runs and idles fine until it begins to warm up, then no idle but will run at 1500 rpm. But at 1500 if I slightly adjust the throttle or flic on the A/C it will die.
It's not BRG, it's blue-ish silver. Got it from my Father in law when he passed. It's been in the family for about five or six years.

Abacus changed the fuel filter when the swapped out the pump within this past 12 months so I MIGHT be able to mostly discount that. I jacked up the car and was getting ready to yank it when I noticed how shiney it was and checked my receipt.

I pulled the air tube when I did the throttle body response test yesterday and it did not looked hammered, but I did not give it a thorough inspection.

I'll try the temp sensor next. (ECT?)

I just want to rule out some of the easier, more common issues before I turn it over to the pros at Abacus

 

Grrrrr..... Not the ECT either.

 

My Corvette did this years ago and it was the CAT that was clogged. It idled ok, but as soon as I applied power, it almost or did stall. Not saying it is the issue, because you should be getting a code, but couldn't hurt to check.

 

Update: Got a code reader, there were no codes present other than the MAF and ECT when I tested them on Friday. I cleared them and wanted to start the engine and NO DICE.....New symptom (that is not intermittent):
Fuel pump makes no noise and no pressure at the Schrader valve. So this is a more direct and pressing issue, without fuel, you get nothing. I'm wondering if the is more closer to the root of the issue. My history with fuel pumps is they are functioning or dead, I've never seen a fuel pump in a "dying" state. I'll try swapping relay's when I get home this evening.

 

Sure sounds like a bad fuel pump. Any other electrical issues? Sometimes water gets in the trunk and will short out fuses in that rear box. I would also check fuse and relay box in the engine compartment.

Maybe Abacus owes you a redo on the fuel pump. Or maybe try Todd Fuller at Checkered Flag (ouch $$$).

Remind us: what is the status of the throttle body and timing chains?

I am guessing the MAF and ECT codes were set when you disconnected them; but that shouldn't cut off fuel flow. It still turns over, it cranks? right. I think it is the pump fuse. But why?


UPDATE: I just noticed Don posted these a few threads down in response to another fuel pump problem:

"What are the symptoms and how was fuel pump failure diagnosed? Has your mechanic ruled out the fuel pump relay (R4 in the trunk fuse box), the pump fuse (fuse #7, 20A, in the trunk fuse box), corrosion on the electrical connector to the pump/evaporative flange, corrosion on the ground point referenced by the pump (right rear side of trunk), control power to the fuel pump relay (fuse #16, 10A, in the LH heelboard fuse box), or other possible causes of no fuel delivery, such as the fuel injection relay?"

 

I agree, usually fuel pumps are alive or dead usually, but as Jhartz notes from Don's post, corrosion can create such issues. Do you know per chance what fuel pump your car was replaced with?
Another possibility may be the crank positioning sensor, if the ECM isn't seeing it, it will not run the fuel pump.

 

Latest update: Swapped relays (I can hear it click when my son switches on the key.), checked the fuse in the boot, checked the fuse in the left side heel board. All are good and very clean (as in no corrosion anywhere).


Looking like I got a trip to Abacus in my future.... Anything else I may have forgotten to get the fuel pump on? Isn't there a bypass thing to force the fuel pump on? (I'm going to search...)

 

You can take a wire and crimp two spade connectors on and jump the switched pins in the fuel pump relay and check for pump noise/fuel pressure then.

If a shop recently did a fuel pump, maybe they kinked a line. If they hamfisted removing the tank they could have easily bent or kinked a line then. Or maybe there's a clogged fuel filter? That's an easier one to test/replace, and cheap. With the car off the ground you should be able to follow those lines from the fuel filter to the tank from underneath the car and look for obvious damage.

 

In a pinch you can bend a large paper clip into a U and use that to jump the relay terminals to see if the pump runs. Some people put a piece of electrical tape around the middle of the paper clip to serve as an insulated handle, but as long as no other part of your body is touching ground when you jump the relay socket, you won't be shocked. As insurance, hold the paperclip with one hand and put your other hand in your pocket.

To test the integrity of the wiring harness between the relay and the pump, disconnect the harness from the evaporative flange on the top of the fuel tank and measure for battery power when the relay clicks on or you jump the relay socket. If you have battery power at that connector, then the pump or the wiring inside the tank is the issue.

I also like nilanium's other suggestions about a bent or kinked line and it's always a good idea to change the fuel filter just to rule it out.

Cheers,

Don

 

Thanks guys! Tonight I will jump the relays "switched" pins and listen for a 'nice softly whirring sound' (fingers crossed). I'll also try to see if voltage is being applied to the pump thru the wiring if I don't hear it, as Don suggests.


I'm intimidated by the fuel pump swap as I think I may have mentioned earlier that I tried to pull the fuel tank twice and failed. My big gorilla arms / hands came nowhere near the disconnects, heck, I couldn't even see them. I was half tempted to drop the rear end. Of course after researching this current issue it seems as if some folks DO drop the rear end to access the fuel line disconnects.


I'm not a rookie at this stuff, rebuilt Kawasakis, Harleys, Fords, Chevys, Triumphs, Internationals and Muncies. Even tangled with some Lucas wiring issues! But the fuel tank kicked my rear and I felt weak when I gave up..... Maybe I'll get a second chance!

 

Hmmm...., not that I am looking forward to swapping the fuel pump out (I am not), but if I do need to replace it, what pump do I want and where are folks sourcing them from?