Hello again lads.

A few weeks ago, my trusty '93 850 GLT (128,000 mi.) developed a starting problem. It usually starts almost instantaneously first thing in the morning, but lately its taking 4-5 seconds to start after warming up. And occasionally, it starts immediately AFTER the engine is warm.

A few times there was a "sputtering" start after 4-5 seconds with the engine warm.
Everything runs just fine after starting.

The first thing that crossed my mind was the fuel filter. Any ideas on where to look for a remedy?

Thanks!

- thumbs

Fuel filter should have been replaced at 90K, but I doubt that is causing a warm hard start. Still it is less than $20 and easy to repl.

You might be running rich which will foul the plugs a little, so look for minor vacuum leaks. The ECT sensor could be going south. The vacuum line from the fuel pressure regulator could be full with gasoline, and in that case, replace the FPR. A bad FPR will show up as black smoke from the exhaust pipe immediately after start up.

Your throttle body could be dirty, no one ever cleans them.

Klaus
--
Always willing to listen, just not able to take direction.

Klaus,

Looking at everything. No dark smoke after warm start.

I'll get back to you. Thanks.

If you get a chance, after parking the car with a warm engine, pull a spark plug and see if it is wet. It is possible that you have a leaky injector???

Is the engine coolant temp sensor original to the car? That might also warrant a check.

Klaus
--
Always willing to listen, just not able to take direction.

Well, the ECT is no doubt original to the car as I've had it since '03. Is there any way to assess the ECT without replacement?

BTW, my thermostat is toast. Over the winter, (Florida), I noticed the temperature gauge was below normal and the heater was sorta luke warm. I recall reading one of your posts a while back where you mentioned the thermostat fails open. Haven't got to it yet. It it crucial?

Anyhow, I warmed up the engine tonight, and waited 10 minutes. Started instantly. Did it again, waited, and the engine started instantly. Went for a drive, turned it off for maybe 5 minutes, and encountered my 5 second crank before it started a little reluctantly. No smoke from the tailpipe.

I'm ready to investigate the vacuum lines, but I really don't know what to look for. Is there an old post with instructions for troubleshooting vacuum issues?

Regarding a leaky injector, I guess you're suggesting I pull all the plugs one at a time with the engine warm. Right? Sounds easy enough.

New fuel pump relay 3-4 months ago. I'll probably do fuel filter in the next couple days.

Thanks for your patience.

- thumbs

Using a multimeter, you can check the resistance at the ECT sensor, the resistance will increase (numbers get smaller as the temp increases):

68F = 2800 Ohms
104F = 1200 Ohms
212F = 150 Ohms

So a cold engine should be around 2800 and a hot engine around 150.

Many on this board suggest swapping out the thermostat and the sensor at the same time, due to need to drain about a quart of antifreeze to do either. I disagree. When the ECT fails, it is easy enough to replace without a lot of spillage - just use a finger to plug the hole. The ECT and thermostat NEED to be OEM, do not get knockoffs.

Running on a 'cold' engine for long periods due to an open thermostat will increase the likelyhood that the plugs are fouled. The ECT reading low will cause the engine to run rich eventhough the cylinder themperature is hot. Replaceing the thermostat should solve your hard start problem.

Klaus
--
Always willing to listen, just not able to take direction.

Klaus. It's been a while, and I meant to get back to you after i finally resolved my issue.

The car finally decided not to start at all in a drug store parking lot (mid July).

I called AAA and started poking around under the hood while I was waiting for the tow home.

Turns out the heavy red (ignition?) wire connected to the positive battery terminal had finally completely rusted through and broke off. I removed some insulation, cleaned things up, and re-attached it to the battery post.

Haven't had a hiccup since.

Thanks for your time and patience.

- thumbs