Hey all...

Okay, here is my sad long story.

1990 Bonneville with the 3.8L motor
102,000 miles

Got the car in Nov. Ran perfect for about 2 weeks. Found out that the previous owner (a scary backyard mechanic) replaced the trans cooler lines with rubber hoses when they blew off and the car puked it'* fluid out on the ground. Got it towed and fixed, and again ran great.

Thanksgiving morning, it was really cold here in MI, and the car refused to start. Would crank and crank and crank, and never fire. Recharged the battery, threw in some dry gas, and tried again. No start. Thinking the gas lines were frozen, poured some hot water on them. The car then started, but the weather had also gotten warmer, so it might have been a coincedence.

2 weeks later, same thing... crank and crank and crank, no start. Had it towed in, the mechanic did the diagnostic, and could only find a low on the MAF sensor. Found out that the sensor was broken, and replaced it.

Ran great again for 2 weeks, then again... no start. This time, the battery was dead, and the mechanic found it was a bad alternator. Replaced it and the battery, the tech cleaned the fuel rail and intakes, and replaced the plugs.

Ran good for about 3 days... and again, crank and crank and crank and no start. This time the tech came to my house, and found that it would fire when the ignition is turned from START to OFF. They replaced the ignition switch and plugs and the coolant sensor (all for free).

Ran perfect, I mean absolutely perfect, for 4 days, and then again, you guessed it... crank and crank and crank... no start. They towed it in again, and when it got to the shop (as it always has before) it fired right up.

At this point, the techs are at their wit'* end and so am I.

We've now replaced:
alternator
battery
ignition switch
coolant sensor
MAF sensor
plugs & wires
fuel filter

Does ANYONE have any suggestions as to a lead to look at? When they run the diagnostics, it comes up completly clean, no codes, ever. The car seems to have spark, and fuel, and air, and it refuses to fire.

Thanks in advance!
Toly

Did they check the fuel pressure? Sounds like fuel pump ,or booster.When it did run , did it run smooth . Also the guys with all the smarts here are going to want your model and trim in your signature so put it there please.

Yes, checked for both spark and fuel, when they were at the house... both were fine.

Fuel pressue is normal, no codes set per the diagnostic... though I don't know for sure that the crank sensor would show up there.

The only correlation I can make is when the car sits overnight and the temp gets down near or below freezing.

When it starts, it run perfectly. Smooth idle, no hesitations.

Thanks!

Could be the ignition coils getting weak. You can easily check the secondary side of the coils by pulling the wires off each coil & checking the resistance across the posts. All three readings should be very close. Check out the following thread.
http://www.bonnevilleclub.com/forum/...48&highlight=A

Hello and welcome to the club.
Unfortunately intermitten no starts are hard to track down other than the process of elimination.
Sounds to me like you have a bad connection at the ICM or one of the sensors or the crank sensor could be intermittenly failing.
When you get a no start in addition to checking for spark and fuel you should also be checking for injector pulse.
I would start there and also remove the ICM connector, clean and tighten up on the sockets and apply dielectric grease.