94 3slow missing, hard start

[RGraff]

I've got a '94 with a 3.0 six cylinder, five speed and 140,000 miles.

Driving home yesterday, engine warm, 75 degrees outside, it starts missing and hesitating. Smooths out on its own and I continue into town. Stop off at the store, get back in, won't start. Crank and crank and crank...finally starts. Continue driving, hesitates momentarily again, then smooths out on its own and drives fine. Park it, try starting it later, no bueno. Crank and crank and crank. Just about when I'm ready to give up it finally catches and starts. Runs fine all the way to the mechanic. Long story short, mechanic can't find anything wrong. Thinks it might be MAF but can't say for sure.

Any thoughts?

 

[RiFF RaFF]

I've got a '94 with a 3.0 six cylinder, five speed and 140,000 miles.

Driving home yesterday, engine warm, 75 degrees outside, it starts missing and hesitating. Smooths out on its own and I continue into town. Stop off at the store, get back in, won't start. Crank and crank and crank...finally starts. Continue driving, hesitates momentarily again, then smooths out on its own and drives fine. Park it, try starting it later, no bueno. Crank and crank and crank. Just about when I'm ready to give up it finally catches and starts. Runs fine all the way to the mechanic. Long story short, mechanic can't find anything wrong. Thinks it might be MAF but can't say for sure.

Any thoughts?

I had something similar recently with my 93. Ended up that the resistance in the distributor was WAY off when the engine was all the way warmed up. Had to replace it.



Cold start - no problem
Hot start - took a lot of cranking, and key turning before she would fire. Run rough for a while before evening out.

Hope this helps. At least it gives you a starting point.

:roadkill:

 

[RGraff]

Just got it back from the mechanic. Never did find the definitive culprit but, in the course of trying to track the problem down, at one point they unplugged the MAF sensor, did what they had to do, then plugged it back in. No more problems. No hard starting, no rough driving. WTH?

Anyway...a $57.00 bill later and no closer to finding the trouble, although it runs fine now. Weird.

Hope it doesn't leave me on the side of the road any time soon.

 

[RGraff]

Thanks for the reply RR and I asked about that. Mechanic claims to have looked at what you mentioned and it checked out fine.

 

[RiFF RaFF]

Just got it back from the mechanic. Never did find the definitive culprit but, in the course of trying to track the problem down, at one point they unplugged the MAF sensor, did what they had to do, then plugged it back in. No more problems. No hard starting, no rough driving. WTH?

Anyway...a $57.00 bill later and no closer to finding the trouble, although it runs fine now. Weird.

Hope it doesn't leave me on the side of the road any time soon.

Thanks for the reply RR and I asked about that. Mechanic claims to have looked at what you mentioned and it checked out fine.

$57.00 is a lot cheaper than a new distributor!

Could have been corrosion in the MAF contacts. Isn't engine gremlins fun in an older vehicle?

:doh:

 

[RGraff]

Gremlins are sneaky little bastids but they beat car payments! :thumb3:

 

[77'911]

First, if you've never replaced the EFI relay, you might consider doing so. I would check the following:
1) check fuel pressures (rest and running).
2) o2 sensor, replace if the sensor has 90k or more
3) t-stat ( make sure it is not staying open, or partially)
4) replace fuel filter and plugs.
5) check for vac leaks around injectors and clogged pcv
6) clean out throttle body
regards

 

[RGraff]

77'911...appreciate the suggestions. Have never replaced the EFI relay. Not sure about fuel pressures but the O2 sensor appears to be original. I personally had the t-stat, fuel filter and plugs replaced when I bought it (about 18 months ago). Also did a sea foam treatment about six months ago.

I talked with the mechanic a bit more and they're confident it's an electrical issue. That claim comes from the fact that when it's not able to start they're finding no spark. They just aren't able to track it down. To me it's acting like a fuel supply issue but what do I know. It's giving me problems once again. Hesitates and misses at speed. Once it's parked it takes forever to get it started again. Then when I get it going it runs fine. Symptoms come and go.

No Toyota dealerships in our area. Trying to find a local mechanic that has experience with them.

 

[RGraff]

Update...well, nothing to update. Mechanic number two has no clue and is waiting on help from another mechanic who won't have time for me until later this week. He too has figured it's electrical but can't seem to diagnose the culprit.

Frustrating