96 trans sports surging, could be the MAF I repaired or the heated O2 that got some coolant.

[snoozin]

Problem: Will only start if engine has been sitting cold for a day. Its starts up no problem then surges. I have done this several days. I let the engine run for 10 mins, then shut it off. Then it cranks but no start. Unless i wait a day, Then it starts up again no problem. but then does not start once the engine is warm.

I have a scanner, I need help in determining which o2 sensor is the problem. The MAF seems to fluctuated in GPS at Idle but I think thats normal.

I'm thinking all that coolant that went through the engine after I cleaned it out contaminated the upstream o2 sensor. I read that silicone in the coolant with dirty the o2 and cause this surging problem.

I know the MAF was damaged and repaired. I know IAC valve is a possible culprit. If i increase engine rpm manually its smooth, the MAF GPM is increasing smoothly If I remember right.[IMG]

On the instrument cluster, The engine temp is at max always, with key on. The RPM gauge is no longer moving. And I have to find the low coolant level sensor. As that light is always on.

I have no MIL/ check engine light on. It was on but I disconnected the battery.

I have 350000KM on it btw.Its the 3800.

It had a bad coolant leak which got coolant steam in the air box, all over the MAF, intake ect. I used some some carb cleaner all over the intake, and used some alcohol on the MAF.

The MAF was Damaged, So I soldered it.

I changed all the spark plugs. tested all the plug wires.

[snoozin]

After the engine is shut off, It cranks but does not start. The temperature gauge is always at the maximum.

[snoozin]

On my scanner it shows that engine coolant temp is -60F, with the engine being off for the last day.

[snoozin]

On my scanner it shows that engine coolant temp is -60F, with the engine being off for the last day.

[LMP]

Originally Posted by snoozin

.. btw.Its the 3800. .

...no...either is it not a '96, or it is not a 3800. Last year for the 3.8 was '95.
After that, 3.4 only
What you describe is relevant of crank sensor failure.

[snoozin]

My mistake,your right, its a 3.4L. Any Idea what I can check or do next. I think my biggest issues is no reference voltage at the ect. I got to find the other end of the connector as I cant see it.

If I can get it started, that does not mean the crankshaft position sensor is constantly. I hope its the CPS, I will test it. That would make sense, because I remember seeing the crank sensor wired into the tachometer in a diagram.


I did get some carb cleanter on the Throttle position sensor when I was cleaning the coolant out.
I noticed that when I pump the pedal 5-10 times before I crank it its doesn`t seem to help.

I`m thinking I should get it started, and go for a gm drive cycle to get some of the codes to come back.

Should I pull out the idle air control valve out and inspect and clean it. I know that can cause hard starts. I know a bad ect can cause hard starts. To me I think I have more than one component now contributing to my intermittent starting issue.

If I disconnect C100, the Tachometer ECT gauge goes from 260f to the lowest setting.

When I had the van running, I remember holding the throttle down a bit to 2K RPM and the MAF gps was constant like it should be. Makes me think the Mass air flow sensor is now the issue.


On my scanner the tps seems to be working properly.

[snoozin]

I discovered a section of the engine wiring harness which was expesed and was chaffing... several wires are corroded in that harness, another part of the harness horizontal with the road had a entrapped a pool of coolant. I checked all the splices and connections for corrosion, all is good. I`m sure I found another problem or hopefully the cause of this problem. On the top of the transmission, next to some linkages, I think is a module that is a smile for 20Pin connectors.the Socket on the module, (that the connector connects to) Cracked right off the module. I will look closer. I remember In the service literature, when the coolant temp gauge is at 260, look for a short or an open at C100, and this module is the next thing connected to it.


Its a large connector and its the first obvious problem I found so far.

Also the straps that hold down the Crankshaft position sensor wire away from the exhaust crossover, let go. It was not accessible enough form see any check it for heat damage. Wire loom for cps is brittle.




I already fixed the intake tube crack, all the hoses that had damage I fixed with good epoxy.

I now have a right turn indicator light partially lit on my instrument cluster

[snoozin]

I tested the crank sensor, while cranking its 0.3 to 0.4 volts and 3 volts a/c while running.