My D1 has failed to start for me a couple of times AND even died one day after a couple hours of driving.

I think I'm on the right track, but might was well review while I wait for parts to arrive. (Thinking i's fuel relay, but read on)

1) Drove down to work (45 mins down the mountains). When I came out in the afternoon to head out, it would turn over but not start. I pushed the schrader on the fuel rail and got mostly vapor/spit. Left it to sit overnight and it started right up the next morning.

2) Drove down to pick up some wheels and snow tires and back up. about an hour and 30 of driving. While waiting for my kid to come out from school, the engine stumbled over and died. Left it sitting, came back about 5 hours later and started right up.

3) Replaced the crank sensor. (I made this job 100 times easier by cutting a small access hole in the inside fender. I'll write it up when I get a chance.)

4) Drove down, dropped off wheels for mounting at costco, started up again drove to work, no problem. That afternoon I drove across town about 10 mins and it wouldn't start in the NAPA parking lot. Left it to sit overnight and it started right up. (Thank god for my bus pass from work)

I troubleshot for a while at Napa. Picked up a new spark plug and got someone to turn it over while I grounded it with the wire from a cylinder. Nice bright spark. So, probably not the crank sensor. Seems to just be fuel.

I've ordered a new multi-function fuel relay. (mine is a 1998 D1) and I got a new inertia switch since one of the mounting tabs on mine is actually broken.

I'm thinking about replacing the fuel pump while I'm doing work. Pulled up the carpet and found a couple of the access panel screws are missing. It's probably been replaced at some point. I may just get a $20 spare so it's on the shelf.

Here's my working theory. The relay box probably has a mechanical relay inside it. It's probably got some carbon built up and after a couple hours of running the resistance increases enough to cause failure to connect. Since the thing will die without that relay, I got a new one rather than a used 17 year old part.

I'm hoping it's not the fuel temp sensor. I actually iced the temp sensor down at Napa in hopes that it was the problem. Nothing came of it. I also tried disconnecting it with no result. Oh, I also read the codes since Napa was right there, nothing but my usual dying secondary o2 sensor.

 

Fuel relay is electro-mechanical - coil and contacts. They generally either work or don't. I still have my original with nearly 200k on it. What are the code(s) your getting, might help diagnose this a little quicker. The fuel pumps on the other hand can get flakey when the brushes start failing. Take a look at the one you have, look at the pickup screen, if it has hard buildup on it it's probably original and I'd be willing to bet that the brushes are heavily worn. Fuel pressure can be measured with a tire gauge to get a quick look at pressure, 34-36psi is spec. Look at the fuel pump connections, look for burned/brown discoloration - high resistance for either corrosion at the connector or brushes causing high resistance. That should get you started....... Also the fuel pressure sensor on the pump housing is tied into the throttle position circuit, that has caused one of our forum folks some grief in the past. If he jumps in he can elaborate, I don't have the same setup.

 

There are no codes for this problem. Only the flaky o2 sensor.

I'm going ahead and ordering an airtex pump from Amazon. $40 vs $20-25, but cheap insurance. (and it'll be here quick!) I'll certainly report back on what I find.

I'm curious about the guts of the multi-function relay. It's certainly not a simple standard relay. It's got some other functions in there, and I'll bet it's susceptible to solder cracks. From the shape, it's likely a PCB with several relays and some passives mounted. I may cut mine open once the replacement arrives...

 

It uses only one coil contact for the fuel pump, the early had two, the later had three and none of the others are used, dead circuits. Been there, done that. If the contacts are severely pitted maybe but I doubt it, not that much current is being passed through it.

 

Today I swapped out the fuel relay, inertia switch and the fuel pump.

Relay and switch were from BA. I ordered the actual airtex pump from Amazon.

The pump was easy to replace, but putting the lock ring back on the tank was a pain.

After the swaps things started right up. So far so good. I will say that I agree it was probably the pump. However, since I live in the middle of nowhere I don't mind the extra insurance of the new relay, switch and pump.

To celebrate, I added some terraflex spacers to get my turn radius back. I like the look, but mostly I like not rubbing on the freaking radius arms.

 

Hope you have it fixed. If symptoms persist you may want change the fuel filter.

 

Hi there Willo, can you please post the amazon link to the Airtex pump. I have the same problem and can't find a pump under $150.00

Thanks!

97 SD

 

Yours is different, 150 should be entire assembly cause you should be non ael you have the round evap can under hood

The pump he mentions is for the ael models with square canister cause the fuel assembly is like $500 so worth rebuilding with new pump


Check d1 tech section

 

Tom, are all 97's AEL? If I recall correctly that is the year they changed and some 97's are....and others are not. For instance, my 1997 IS an AEL model.