'85 Mondial Cold Start Problem

I wonder if some of my fellow Mondial owners can help me out with this. Seems like most everyone has had this problem at least once before. Now it's my turn!

My 85 Mondial Qv cab has a hard time firing when cold. It cranks fine. Warm starts are instantaneous - as long as it hasn't been shut down for more than an hour or so.

When cold, the car will briefly fire but then die immediately. Additional cranking will only give a short sputter at best - no reaction at all, usually. After 8 to 10 tries later it may FINALLY sputter to life. It will also need MUCH coaxing with the gas pedal to stay lit, but after a minute or so it will idle fine on its own, unattended. It will run fine and restart fine after it warms up.

Sometimes lately it won't sputter to life at all. I'll leave it for an hour or so and try again later and usually it FINALLY will fire up.

I would normally suspect the cold start injector but somewhat doubt it - I smell raw fuel when it acts up like this. I don't think lack of fuel is the problem. It almost seems like it floods out. It also give the same "flooded engine" reaction when it finally does start (sputters, high revs and wants to die) until it eventually clears out.

Any ideas?

 

jwise-

Funny you mention this as it has crossed my mind. What's confusing is that it starts fine and runs great when warm so I've somewhat discounted spark as a problem. It is a very simple test so I will try it out though.

 

wolftalk-

If you're wondering where the FI ECU plate is in a Mondial cab, I'll fill you in... ...and probably answer my own dumb question in the process.

It is located directly beneath the power radio antenna in the right rear corner of the trunk. Did I mention directly beneath the antenna? Yes, the antenna with the fender gasket missing. Yes, the same antenna that lets rain/wash water drip directly onto the ECU plate. THAT antenna.

You tipped me off when you mentioned the frequency valve buzz. I know all too well about that buzz and what happens when it doesn't happen. BUT, this time it buzzes just fine - but only because I just recently cleaned the contacts on the Bosch relay mounted where? The ECU plate, which is where? Under the leaky antenna! (OK, I won't say it again).

My job tonight is to clean ALL the connectors on the ECU plate. Funny thing is that I purposely left the access panel off just in case I had to get to the plate again. Why did I ever think that? Maybe I should put in a door, instead.

And yes, I am going to replace the antenna with a new one. Seemed the old gasket dry-rotted into pieces from age. The antenna didn't work anyway.

I'll keep you posted. Stay tuned...

 

The story so far...

I attacked the FI from all sides-

1. Cold start injector- 12v to the injector makes it click. A test light on the wires feeding the injector turns on for a few seconds when cranking engine, then turns off, like expected. A "test fire" indicated a nice conical mist spraying from the end into a clear Snapple botttle. Did not see any fuel drip when not energized. About all I did is wipe some dirt from the end.

2. AAC- Verified it's open when cold and that the coil resistance was good (25ohms). Verified that it had 12v at the wiring with ignition on.

3. Air metering plate- Moves freely and smoothly. No sticking or dragging.

4. Frequency valve- BZZZZZZZZ!!!!!!!! All OK.

5. Thermotime switch- I know the "time" portion works because of the test light on the wiring feeding the cold start injector (see #1 above). Haven't really focused on the "thermo" part. And, I hate to admit it, but where the heck is this thing buried?

6. Differential pressure valve- (Here's a good one) I removed the coolant expansion tank to get at the AAC underneath. While I was under there I saw that the electrical connections to the DPV were green with corrosion. I cleaned them up.

7. Electrovalve- Just really looked at and cleaned connections and inspected vacuum lines. I understand that this only really cut out the "cold start" circuit components when it get up to normal operating temperature. Not the time I'm having my cold starting problem.

8. Thermoswitch in bottom of expansion tank- (another good one) I could swear that one of the wiring terminals was disconnected BEFORE I removed the expansion tank. They were covered with dirt, too. I cleaned and straightened the connectors so they seated firmly now (seemed loose before).

9. Wiring- The expansion tank had pinched some wires between the tank and the rear engine compartment bulkhead. Bad enough to see the copper in the wires. Which wires? They were to the tank's thermo switch and the diff pressure valve. Not cut through but very possibly shorting together with the metal tank. I insulated the wiring with liquid electrical tape and re-routed. I also checked all connections on the MCU and relays. Also, all fuses were OK.

Now, after all this I turn the key and VROOOOOOOMMMMM!!!... ...for about 4 seconds! Then dead. Just like I turned the key off. I coaxed it back to life with a small shot of starter fluid. STARTED AND RAN GREAT!!! I turned it off and on- RAN GREAT!!! I called it a night and slept well.

Next morning (this morning) I tried again. BACK TO THE SAME PROBLEMS!!! Hard to start a cold engine! BUT, this time my Dad smells raw fuel at the rear. Is it flooded? I treat it like a 1969 Chevy that flooded out - pedal to the floor and crank away. After about 10 seconds it sputters to life and runs as normal as could be. Even goes into fast idle mode and then settles down to a smooth as silk idle.

Sorry about the long winded post. Can you sense my frustration?

Question of the century: Why in the heck does my engine seem to flood out when started cold?

 

Hi Steve- Glad you can lend a hand here.

I tried as you suggested. When I jumped out the relay socket I heard a relay click - seemed like it was under the dash, and a slight whirrrr. Not the fuel pump, though. More like it was under the dash also. No clue to what this was.

I also tried to start with the cold-start injector electrically disconnected. The usual "nnn nnn nnn Vroom..." ... for about half a second, then dies. It will "vroom" only once, then, as Edgar Allen Poe wrote: "Nevermore". Any more cranking yields just that - more cranking. No vroom after the first one. It just will not restart without MUCH cranking and waiting in between. Sometimes hours worth of waiting. And the raw fuel at the tailpipe smell is back.

More on the fuel pump: I have a feeling that the safety cutoff (the one that shuts the pump off if the key is on but the engine is not running) is disabled. I have some "creative" wiring to the fuel pump wires at the fuse panel connector. The pump runs as soon as I turn the key to "on". This may explain why I had no response from the pump when I tried your jumper trick.

I'm on vacation this week and guess what I'm doing? This. HELP!!!

 

Re spark: I did try it but with "iffy" results. Makes me almost think my timing light is defective. Yes, I know, maybe it's not a timing light problem but really an ignition problem. I want to get a 2nd opinion (my friends light) before I eliminate or confirm that as a problem. It does run absolutely fantastic after its been started, though.

I'm looking into now what Steve (91tr) mentioned about the wiring. His jumper trick didn't work and I just found out why: My fuel pump wiring and AC wiring connectors are reversed in the fuse panel connector!

It seems that those are the two chronic terminals that overheat in the white connector, leaving that nice brown mark in the white plastic. I've seen the pictures many times before on other cars, and mine is no exception. The third and forth contacts from the bottom of the vertical connector on the right side of the box. They were repaired once upon a time (the funky wiring I mentioned) but it seems that the wires were reinserted into the white connector in reverse. Thus, the AC circuit became the fuel pump circuit and vice versa. The relay clicking and whirrr from under the dash that I heard when I jumped out the fuel pump relay was actually me "hot wiring" the (new) AC circuit!

The car actually runs fine when it does start, which puzzles me. Maybe the fuel pump only works when the AC is on!

Back to tracing wires...

 

OK, I'm back...

Now, fuel pump fuse and relay control the fuel pump. AC fuse and relay control the AC. Much better! So far so good.

Tried it first without the "91tr" recommended jumper (I put the relay back in). First thing I noticed is that the fuel pump didn't make a sound and the frequency valve didn't buzz when I turned the key to "on" (like it used to with the crossed wiring). That tells me that the engine-not-running safety relay is cutting off the fuel pump as designed. Still good, so far.

Cranked the engine: "NN nn nn nn nn nn..." Nothing.

I put the relay jumper in and the fuel pump whirred and the frequency valve buzzed.

I cranked the engine again: "NN nn nn nn nn nn..." Nothing, again. PU! Fuel smell again!

I'm going to put the battery on charge and air out the garage. Tomorrow, I'm verifying my ignition is good or bad, once and for all.

Steve- Did you have a "step #2" after the relay jumper test?

 

I'm looking into the ignition end of it. Here's what I did:

1. Tried the timing light trick on both coil high-voltage leads. Won't strobe on either one!

2. Checked voltage to the coils. 12v to both.

3. I doubt both crank sensors went bad at the same time. Likewise, the ignition modules. And, it runs fine when warm.

4. I took a new spark plug, grounded the base of the plug and connected it to #4 cylinder plug wire (easiest to get to). The strobe light now strobes on the rear bank coil wire, but only when that one plug fires!

Thinking out loud now...

My conclusion: ALL my plugs are fouled. At least #4 plug has a shiny new looking electrode. Not tan, but looks like it was "washed" by some kind of "solvent". Hmmmm. I think I have a (or some) leaky injectors that allow residual fuel pressure to drip down into the cylinders overnight. Also, in the mix here was the miswired fuel pump circuit that turned the pump on before I even started to crank the engine over (possibly causing more dripping from the leaky injector(s)). Add to that the extra shot of fuel from the cold-start injector and "Voila"! - cold start flooding!

The shot of starter fluid spray and treating the engine like a flooded 1969 Chevy (pedal to the floor and then crank away) would manage to bring the engine to life most of the time. After that it ran just fine. Even restarted fine after a 2 hour wait. It's the overnight wait it doesn't like.

I also think that the fewer drives I took during the winter and the month of down-time while the interior was redyed/10 speaker stereo installed took its toll. It didn't get like this overnight, but did get consistently worse each time. I chalked it up to lack of use and promised myself to drive it more often. Promises...

Am I on track here? Suggestions on how to remedy? I'm thinking a long drive with a full tank of 94 octane and a bottle or two of fuel injector cleaner would help. What is that stuff? Techron?

Also, is there a preferred method to start a flooded car other than my "'69 Chevy" method?

Many thanks. Waiting for your feedback.

 

THE DEAL:

Pulled out #4 plug and had a friend visually watch the spark happen or not. Cranked away. Timing light did not strobe and the plug did not spark. ... as expected.

Cleaned up with 600 grit paper and regapped plug and retried. Sparked and strobed! Fantastic news (for me).

BIG QUESTION: Auto parts store says my problem is directly related to the new 10% ethanol blended gas - the only kind available in NY at least. I bought a bottle of Techron but am wondering if there is a spark plug recommendation that will help burn off the crap that's fouling ALL my plugs?

I plan on replacing all plugs - What is a good plug to use with today's poor quality fuels?

 

I'M DONE!!! It starts and runs great!

For some previously unknown reason, my car was getting more and more difficult to start when cold, but it always ran fine when warm. I know, you've read the posts (and are probably tired of seeing them by now).

Problems found and remedied:

1. Differential pressue valve wiring corroded.
2. Thermo-switch in bottom of coolant expansion tank was disconnected.
3. Pinched/shorted wiring to both items in #1 and 2, above.

These first three caused difficulty starting which led to a flooding condition. Combine that with the wonderful 10% ethanol gas and the result was ALL eight plugs fouled and refused to fire. Therefore...

4. Replaced all spark plugs. Which led to...
5. Replace bad plug extender
6. Properly gap new plugs before installing (spec is 0.6-0.7mm). Old plugs were >0.8mm.

Also, along the way I found...

7. AC and fuel pump wiring were crossed at the fuse box connector.
8. Restored fuel cut-off safety circuit (result of rewiring connectors in #7, above).

After an oil change, a half a tank of 93 Amoco with a bottle of Techron and an hour and a half drive and she purrs like a kitten. Starts RELIABLY now. First time, every time, hot or cold.

Thanks for all the helpful suggestions and troubleshooting tips. Seemed I needed every one of them considering all the things I found. Also, thanks for being my sounding board while I bounced ideas out there. I also know A LOT more about my car now - in both the FI and electrical departments.

I have also searched and read just about every archived thread with the keywords "Mondial", "hard starting", "flooding"... However, I would venture that perhaps a third of them just die off with: "I'm at a loss... The flatbed is taking it to the shop in the morning..." and no clear resolution of the actual cause of the problem. Commonly, the last post is something like: "What did you find... Is it fixed now?" from an inquiring mind that wanted to know.

I hope my "epic" helps someone in the future. At least they will know what I found wrong (although, admittedly, not entirely typical) and what I did to resolve the problem. And if they search the archives with the keywords "Mondial", "hard starting", "flooding"..., they'll have a book to read here!

Thanks again.