Hi all. Love the forum and have used info here to keep a past rover running well. Now I am the lucky new owner of a '96 D1, which unfortunately dies sporadically.

What I know...

-This is a working truck...it starts, runs, drives. I have lapped the neighborhood with no issues for quite a while, fully up to temp with no issues. -Try the same thing on a different day and at some point the truck may cut out and refuse to re-start

-It has a high-idle and numerous codes and while I could choose to attack the codes (o2 sensors, random misfire, abs faults, insufficient coolant temp) I feel keeping it running should be step one, before I try to get perfection from every system.

-It has recently had a fuel pump, pump wiring harness, main relay.

-When it dies, it will turn over, but not fire. Everything else works as normal.

-I suspected crankshaft position sensor, but after it cools for an hour, still no re-start. Someone on this forum said if the check engine light goes out when you are cranking the engine that is an indicator that the CPS is sending the signal out as designed. My CEL does go dark, while cranking.

-After an undetermined amount of time (overnight etc) it 'fixes' itself and will restart and begin the cycle of uncertainty all over again.

-My wife is getting very good at towing me from the far corners of the neighborhood via strap behind a Corolla

Being so essential as the crank sensor is to starting the engine I think I'm going to throw one at the truck regardless....but do the experts here think I'm barking up the right tree? I'm not sure what 'order' my game plan should be. ECU was another option...just b/c it's not something I can easily diagnose otherwise...so a replacement to eliminate that might be a wise start??

Interested as to what any of you think or perhaps have experienced yourselves.

 

When it is failing to start, try checking the fuel pressure. There's a schrader valve on the fuel rail. Either check with fuel pressure gauge, tire pressure gauge or push it in with something to see if it squirts fuel pretty strongly. If you're getting fuel, check for spark, take a plug out and lay it against a ground and crank. Should be a blue spark. Also, I would clear the codes and see what comes back. I'd check the basics before buying parts.

 

Thanks for the reply Disco. Does the pressure reading I take have to be while turning the engine over (get the wife to turn the key) or just a reading I can take between cranking attempts? I'll try for spark also and report back.

 

It should pressurize when you turn the key to the "on" position. If you listen closely in the cargo area you can hear it. But, bottom line, check between cranks at the valve. It should squirt out strongly, or a tire gauge should hit 30 - 35 lbs. Are you still going to try a crank sensor ? Crank sensor and fuel pump issues seem to be the most common no-start problems - and the security system. Wouldn't hurt to clear the OBD codes and see what comes up too.

 

By the time I got back to the truck last night it was working perfectly again, so nothing to diagnose. I've been reading up on the alarm spider and everything symptom-wise seems to be a good match. I've ordered the bypass, so that will be step 1.

 

Well, big disappointment. My truck does not appear to have the spider unit as factory equipment. Ughh...back to square one.

 

The truck randomly cutting out screams fuel issue. If not the pump then perhaps the connectors on top of the pump or in the driver's rear wheel well. Or the multi-fuction relay under the good by the charcoal canister.

 

Take a good look at the Inertia Switch connector. That is what I finally found to be the problem with my truck after multiple tows home and weeks of messing with wiring. You might want to put a jumper wire in there just for something to try. I have gotten real good at listening for the fuel pump running

 

Thanks for the tips guys. I got a fuel pressure gauge so I'll try to test pressure and then also for spark next time it dies. Honestly the most difficult part of this is HAVING to breakdown on the road in order to start diagnosing. I can't do any of this work at home, b/c it's a great running truck when it's there.

 

Throw a test light in the truck. Next time it dies test for power at the plug on top of the fuel pump, and at the harness connectors in the wheel well. Keep in mind you'll have to be quick like a bunny because the pump is only given power for a few seconds when the key is in Position II.