1990 2.9 - Engine Cranks, won't start - At my wits end!

[Munchie1615]

Alrighty guys, here it goes. This story begins with the purchase of 1990 2.9 V6 Ranger with automatic transmission. It ran when I bought it but needed exhaust, it was cut off at the cat. Also, the guy that sold it to me told me said that the vacuum wasn't working at the connection going off of the manifold to the FPR (that I now know). Regardless, I drove it home that night.

It needed a battery, I put a new battery in. Found out the alternator was bad, I replaced that. Tested to make sure the new one was charging the battery which it was. All seemed gravy. For the exhaust, I put on the dynomax system and replaced the cat and filled some rice krispy welds at the y-pipe. I did notice they filled the hole for the O2 sensor, but I didn't think this would cause a huge issue... The truck was running decent enough for me to move onto the next task. I wanted to do an oil change and a coolant flush.

Oil change: Found the oil was milky, making me think there's a head gasket leak. I completed the oil change adding new oil and a new filter.

Coolant Flush/Head Gasket Situation: I used the Blue Devil cleaner and performed the coolant flush. I also purchased the Blue Devil head gasket sealer as well (the one where it has to idle for 50min). I did this per the instructions on the bottle. After letting the truck idle for 50min I let it cool down and I replaced the thermostat with a new one and tightened everything up. The trucks exhaust looked way better than it did before and I feel like the head gasket sealer worked the way it was supposed to.

I took the truck for a spin up and down the road and as I was getting ready to pull in the drive it stalled out and I haven't been able to get it to start again since.

Here's what I've done:

50/50 Test:
1) Does not start on starting fluid
2) Tested for spark, looks like I have spark per the test light

Compression test:

Cyl 1 = 165
Cyl 2 = 165
Cyl 3 = 170
Cyl 4 = 160
Cyl 5 = 170
Cyl 6 = 165

Fuel Pressure: 42psi (after a couple KO cycles)
Fuel Pressure after 10 min: 34psi

I've tested/replaced:

1) TFI - I thought this HAD to be it, from all the threads I've read and videos I've watched. After replacement, still same story, cranks and won't start.

2) Distributor Cap -- Replaced this as well as the rotor, the "button" on the old cap had a piece out of it and looked compromised.

3) Spark Plugs and wires -- Replaced all the plugs, and wires (yes, I've checked the wire locations to make sure I installed them in their correct location). Even after distributor cap, plugs, and wires still the same result - Cranks and no start

4) NOID light testing -- tested the IAC and all of the injectors to ensure the pulse was firing, this tested GOOD.

5) Engine Coolant Temp Sensor (Outside temp: around 67 degrees F) -- ECM pins 7 & 46 - tested at 43,900ohms -- Tested at the sensor 44,600ohms

6) Air Charge sensor (Outside temp: around 67 degrees F) -- Tested at the ECM pins 25 & 46 -- tested at 43,600ohms -- Tested at the sensor 44,900ohms

7) Checked Timing: Aligned the TDC line and checked the rotor position it was dead on the #1 spot when I checked under the cap

For s*its and giggles I put the original TFI back on to see if that would do anything, since I've read that aftermarket TFI's can be unreliable, I know I need to do the TFI troubleshooting guide that I've found on here - I plan on doing that tonight/tomorrow morning. Still results in a crank and no start.

Today, while trying to test voltage at the Air charge sensor with the KO, I connected one lead of my multimeter to one of the paperclips in the back of the connector and I heard 3 random clicks smelled electrical smoke and found my ECM blew a capacitor. I went to the junkyard today, found a 1991 Ranger with Auto trans and grabbed the ECM out of it -- Reinstalled in my Ranger and I have lights on the dash again but still just cranks and no start situation.

What else am I missing? One of the most helpful videos I've watched was the "I picked Frank Fritz's 1986 Ford Ranger" by Watch Wes Work -- I thought I might really be onto something with the coolant temp sensor like his, but now I'm not sure. I have the 1990 Ford Manual, the 1990 Ford Electrical and Vacuum troubleshooting manual, and the Haynes manual. I have combed through everything I can think of so far.... What the heck am I missing!?

Also, I keep the battery charged up and always check the voltage before I do any testing, it's always around 12.4-12.6 volts. Also, I purchased an OBD1 reader and it hasn't thrown any codes, I checked this before it stopped running as well and never had any codes. I don't know if because I disconnect the battery when I'm done messing around with it if that's why no codes are present or if it just doesn't want to tell me anything.

I think that's everything so far..

This is my first "project" truck, I really want to get this thing running again...

Mary

 

[alwaysFlOoReD]

I had a similar problem one time. I had disconnected a bunch of wiring then put everything back together. Because the connectors were really old and dry, the little orange "o"-rings didnt allow the connector to fully seat. It took me several months to figure this out. Put a little dielectric grease on that oring and the connectors slid together so nice....and the truck started!
Maybe something to check...

 

[bobbywalter]

If it don't start on ether ...

you are no spark....or timing way the fawk out

valve events are wrong.

With 165 cold compression....you would think valve events are good.


Are the plugs wet from fuel?

Correct plugs? Plug Wires ohm good and shown working? Put test unit in wire.

 

[RonD]

+1 ^^^

Do 50/50 test again

If engine doesn't start up then you don't have "good spark" or spark is at the wrong time
This is the ONLY way to test for spark

If you have pulled out the distributor then you may have put it back in 180deg out of time with the Cam
There are TWO TDCs on a 4-stroke engine
TDC mark is at 0deg for #1 and #5, these are Matched Pair cylinders, both are at TDC at the same time, one on compression stroke and one on exhaust stroke, decided by Cam not crank
(Matched Pairs are used to balance an engine, 2/6 and 3/4 are the other Matched Pairs)

If you put crank on TDC 0deg and put distributor back in with rotor pointed at #1 then you have a 50/50 chance of be correct
Which also means.................you have a 50/50 chance of being incorrect, lol
But easy enough to change it
Put crank back on TDC 0deg
Remove cap
Rotor will be pointed at #1 OR #5
Lift distributor and turn rotor to the opposite, if it was point at 1 point it at 5, if it was pointed at 5 point it at 1

Put it back together and do 50/50 test again

 

[gaz]

Muchie,

When you say "milky oil", there is a coolant system breach/failure. If uncorrected, eventually, it will not run or start.

This "Blue Devil corrective action solution", if it involved removing the heads, cleaning, inspecting and determining that the heads aren't warped, installing new intake valley (lower intake manifold) and head gaskets, then I agree with further troubleshooting...if the "Blue Devil solution" did not involve the above described inspection and gasket replacement, then I recommend it.

 

[Munchie1615]

Hey Guys,

I never took the distributor out when I checked the timing -- I was really trying to not mess with anything too drastic without doing other troubleshooting first. When it stopped running it just stalled out, never to start again so far. When I checked TDC the rotor was pointing at #1 cal on the distributor but it's true that could still be 180 right? How likely are these to jump timing, especially with just cruising up and down the street, not beating it hard or anything..?

Also - this might sound like a stupid question but.. the ECM I found at the junkyard was from a 1991 3.0 -- is that considered the 2.9 of that year? If not, I'm probably going to have to order the replacement with the same part number and wait on that before any productive troubleshooting can be done.

I did the compression reading after I did the blue devil gasket sealer (this is just meant to be a home depot runner for other projects and to get around town, nothing too fancy) so I wasn't trying to disassemble everything either, figured trying the gasket sealer would be the first attempt and if I had to later go down the disassembly path. To my pleasant surprise the compression seems to be the least of my worries... Also, the oil currently looks good and the coolant is holding and that was after the idle 50min plus the 5-7min drive I did. I still plan on changing the oil and filter again as soon as I can get it to freaking run!

I'm going to do the 50/50 test again and take some videos. My concern has been do I have a GOOD enough spark to ignite, or am I experiencing voltage drop at the coil or something like that. I'll post here later the videos after testing and see what y'all think. I really thought I was onto something with the engine coolant temp sensor and the air charge sensor (testing those against each other) since that was the issue in the video I mentioned above - which I hadn't seen before in other videos that creates the "crank but no start" event. It's at around the 31-35min mark.

I'll report back with videos later today.

Thanks,
Mary

 

[RonD]

3.0l was not the same as 2.9l, ECM wise or any other way
2.9l was used thru 1992
3.0l 1991 thru 2008, it replaced the 2.9l as smaller V6 option when 4.0l V6 was introduced in 1990

TFI Spark system is autonomous(doesn't need the computer) so engine should start with 50/50 test if spark system is working regardless of ECM model

The computer just runs the fuel system, fuel pump and injectors thru 1994
After startup the computer WILL change spark advance, but during start up TFI module is in full control of spark
If you remove SPOUT connector then computer has no say in spark system at all

 

[Munchie1615]

Thanks Ron -- That's what I figured on the ECM -- I have tried pulling the spout connector before as well, I'll do all the things here in the next couple hours and hopefully get it posted. Thanks for continuing to follow!

 

[RonD]

Although rare the roll pin on distributor gear can break, so rotor(and oil pump) will no longer be turning when starter motor is turning the engine
Lift cap and look at the rotor position
Crank engine
Look again, rotor should have changed position of course
Just to take that off the table

1990 should have CEL(check engine light) on the dash
CEL should come on with key on, that means computer has booted up
CEL should go OFF as soon as starter motor starts to turn the engine, this means computer is getting a Timing Pulse from TFI module
No timing pulse can mean Hall Effect sensor in distributor is bad, also cause no spark
Can also be TFI module or its wires to computer

 

[ecgreen]

I had a no start and everything checked out fine. It turned out to be an unplugged ground to the ECU. Bout kicked myself

 

[rusty ol ranger]

I would be putting the proper ECM in it and going from there. Im not an expert on such things...but i doubt a 3.0 ecm will run a 2.9.

As far as the milky oil....chances are its a head and not a gasket, the 2.9's biggest weakness is the heads. The sealant might have bought you some time but i would plan on tearing the heads off and having them magnafluxed to check for cracks.

Also, if the engine was ran very far with milky oil its a good chance the main and rod bearings are going to self destruct in short order.

However a cracked head shouldnt keep it from running. It might miss or run like shit, but it should still run.

 

[Munchie1615]

Hey everyone,

Later than I wanted it to be but as promised, here's some of the testing I completed tonight:

1) Dash Indicators video

2) Spark Test

3) Starter Fluid Test -- I had already opened the butterfly valve and sprayed starter fluid inside as well as at the opening (as you can see)

4) Rotor Turning while cranking

5) FPR Vacuum line picture -- The guy I bought the truck from said this didn't work, but it ran when I bought it and the whole time I was doing all the other jobs I did before it stopped running. This wouldn't make the truck not start right? I plan on replacing the FPR once I got these other things figured out.

So let me know what y'all think. Going to order the right ECM tomorrow morning so I'll be putting it in, but these tests were all the same result with the original ECM until the other day when it fried a capacitor or two. lol

Have a good night!
Mary

 

[bobbywalter]

When I still had and was working with the 2.9....

The 3.0 was the upgrade ... It threw some codes for steering and evap ..which were addable...and you had to play with the timing slightly...but ran fine....earlier map stuff....from aerostar.


then I was looking at the later stuff to get rid of the pia distributor that was always getting waterlogged .....gain sefi and maf for turbo build....

Seen what the merkur guys were doing early on...based on how bad they were cracking heads ..I decided fawk it and started to do a 4.3 5 speed swap....yes a Chevy swap was the plan in 93.
This goes on and on ...

Just saying ..3.0 can run a 2.9.

At least ..before there was internet we were doing it....

 

[PetroleumJunkie412]

I'll give ya tree fiddy.

 

[Cees Klumper]

I would hold a spark plug to ground while cranking to confirm you really have spark.
Not having removed the distributor or touched much else makes this really strange.
That, and that it won't run on starter fluid.
Bad inertia switch or connection to the switch?
The capacitors in the original ECM can be replaced, good to do anyway as they go bad.
Do you have fuel in the tank? Gauge could be bad, happened to me just last Sunday on my son's car. We thought it still had a quarter tank but it was empty and gauge reads wrong.
2x on the heads, but they are not expensive new and these trucks are worth it.
It'll run again soon with your determination and methodical approach. Wish I could offer more ideas.