J_Ketzer

iTrader: (1)

My 97 is screwing with me again. Doesn't like to get started in cold weather anymore. (Neither do I, but I can't afford to move south yet) Right now the Max is stuck at the bottom of my driveway -- yeah, I tried to roll-start it down the hill and it didn't work -- so I'd like to ask your opinions as to the possible culprit.

There's a year-old battery and good, healthy "crank" from the starter; no obvious noises or anything like that. After probably 30 seconds of combined attempts to start, there is an odor of fuel. The motor just won't actually fire.

For the past few weeks, roughly corresponding to the temperature dropping here in PA, the car has exhibited questionable behavior when starting: it would fire up pleasantly and cooperatively, but it would immediately die if I didn't "blip" the throttle a couple of times. After two or three seconds of help from me, the engine would settle down into a nice and healthy idle, and it would stay that way so long as the motor was warm.

I have also noticed a drop in gas mileage recently, from a pretty consistent 28-29 highway down to about 23. (I drive this car 50 miles a day on the interstate, so there's a significant sample of data to support this.)

Note that if you can convince it to start, then the car does run ok. RPM dips pretty low when slowing to a stop at red lights (down to 200-300 or so) but it doesn't actually die. The engine behaves normally besides that.

These factors lead me to suspect either a fuel or ignition gremlin at play. I don't have any knowledge of electronic engine controls, but Occam's razor suggests that when three things go wrong roughly at once, you should look for one common cause...

Thoughts?

Thanks in advance, guys...

ChrisMan287

iTrader: (34)

Time to clean your IACV and TB.

J_Ketzer

iTrader: (1)

That looks like a good call so far; I appreciate it.

There's a ton of crud on the inside of the TB plate and body, and all the way downstream after that. I wiped down the inside of the TB with a rag and it looks like an oil spill; the whole thing reeks of gas.

J_Ketzer

iTrader: (1)

Well, the TB and IACV are shiny-clean now, but there's no change. The car won't start at all.

What else? The computer's not throwing any codes, incidentally.

defiance

iTrader: (1)

Did you check your cam and crank sensors ??

jholley

iTrader: (13)

Have you measured that year old battery? If it's below 12.2V you'll need to replace it or temporarily recharge it.

If the battery's in good shape you'll need to modify that starter. The air intake was just cleaned and the smell of fuel verifies those injectors are working.

Add a low gauge wire straight from the negative terminal to 1 of the 2 starter mounting bolts. I inserted a hand made 2 AWG wire and it starts much quicker now. While your at it regreasing the starter will also help: REGREASE

Kico

try cleaning the MAF and check both crank sensors and the cam sensors and a tune up might help grounds are a key thing in getting these cars started. I just went through the same thing you are hope this helps.

J_Ketzer

iTrader: (1)

The battery checks ok, 12.45 V even after all of my screwing around. Engine cranking is fast and "healthy-"sounding.

Meanwhile: I tested the cam sensor and saw infinite resistance. Is that even possible without triggering any CEL codes? I figure I have to somehow be checking it incorrectly.

I'd also like to test the fuel pressure (a leaking injector seems plausible) and check for spark at all of the ignition coils, but I haven't got tools for those tasks. I'll have to go back to Advance again tomorrow...

J_Ketzer

iTrader: (1)

Case closed. The cam sensor did it.

I still don't understand how it can stealth-fail, but, well, it did. The car starts, idles, and runs like it's supposed to now - no more RPM sagging at red lights either. That's a pretty good return for a $65 sensor and two minutes of labor.

Thanks to the .org for suggesting this. I would've wasted a day doing useless work, in addition to buying maybe $100 of unnecessary tools, had I just followed the Haynes process like I was going to. You guys stay classy.

MrBr3tt

I've been having the same trouble all winter. I just figured that my car just wasn't a fan of the cold haha but luckily I came across this thread before I gave up!

coopee1

Got to check mines having the same problem

MrBr3tt

Just took my Max to the my mechanic and told him to replace the cam sensor and some other stuff. He replied with "I can replace it for you but there's no guarantee it'll fix your problem, it'll be a guess." I told him that's fine go ahead and do it. He calls me later that day after he checked out my car and tells me it's leaking oil everywhere haha thank you for letting us know what was wrong because the cam sensor stealth failed me too!

r3_JynXed

I recently moved to New orleans from sunny So Cal. And noticed with the cold weather I'm getting the same thing.

I'm new to working on my max and wanted to quickly ask;
How do I go about checking/cleaning/replacing the cam sensor?
I get a few idle problems at lights too and at startup. but more noticeable only when its cold.

Thanks for the help!

bobflood

Easy sensor to pull and replace. On pass side of engine on front cyl bank. Unplug harness, remove one bolt (10mm I think) and pull out. There is an o-ring on it to keep oil in. It's a field effect sensor, so not much mechanical can mess up. Per FSM, resistance between two pins should be: Hitachi 1440-1760 ohms; Mitsubisi 2090-2550 ohms, at 68 degrees F. However, even if it ohms correctly it could still be causing a problem.