Speaking of car trouble - the Dodge is on strike in hot weather

[WhiskeyRebel]

I've got a 93 intrepid with about 106K miles. I believe it's got the smaller of the two engines
available that year.

The past few days in the 90-plus F weather we've had in the Detroit area, the car will not restart if the engine stops after driving 20 minutes or more on the freeway (OK, it's in the left lane of I-696 for those of you who know what that entails). After leaving it to cool off long enough, it starts and runs normally.
Monday it bogged and stalled when I pulled to a stop in a left turn lane, low RPM lugging against the brake in drive. Pushed it into a parking spot along my street and went back after supper. It fired right up.
Tuesday I stopped at the store to pick up a can of badly needed R134 and came out maybe 10 min later and it would not fire. Walked to the gym and came back after maybe 90 min and it fired right up.
Today it bogged and stalled while slowing to pull off I-696 onto the M53 exit ramp. Sorry, that was me. The MDOT wrecker spotted me and gave me a tow home. I haven't tried it yet tonight but don't expect any difference.

When trying to restart it hot, the starter cranks the engine at a good high speed but the engine does not fire. It doesn't bog under accel like the motor is fuel starved. When you start it cold, you'd never know it had a problem.
I haven't yet checked for spark under this circumstance and I don't know how to check for fuel on a TPI engine. I never thought I would wish for a Thermoquad.

I really haven't tried anything yet. What is the first thing I should check?

 

[SPL db]

I had a Nissan Maxima do that to me one year... turned out
to be a bad coil, ran fine when cool, but broke down after
it warmed up. :yes:

Replaced the coil and no more problem! :thmbsp:

Your mileage may vary!

Scott

 

[Reel 2 Reel]

i had an escort that did something simular...but when in between cold and hot..it would quit...wait then restart...runs fine...

The ferd dealier replacd the TFI module...which atached to the distributor...they tried to get me for a PIP sensor...which is inside the dist. to trigger the spark...and a coil wire....and the coil!....i told them just do the TFI thingy...and it was fine eversince....

goes to show ya how much the dealiers try to rip you off....never again!..


as for yours ...if no dash lite...ie SES lite...could be almost anything..but if a SES ...or engine lite....it could be a sensor ...or actuator.......new cars just suck....

 

[markthefixer]

IT MAY be the magnet in the distributor pickup assembly. $15-30 part. Re-timing needed.

This advice held true on many of my different mopars. From 73 chargers, 78 cordobas with the Lean Burn computers (mechanics have many bad names for THEM) through 2.2L chargers and a chrysler newport. IF the car uses a magnetic sensor in the distributor (magnet / coil assembly with a spinning reluctor) and when a tune-up is done and the coil/magnet is not replaced, the magnet ages... more so than if it was kept at room temperature. It looses strength when heated, and eventually there isn't enough signal for the electronics to work correctly. The 73 did a "party trick" where it would skip a cylinger and dump a cylinder full of air/fuel into the hot exhaust system (no catalytic) BOOMMMMMMMM.... I heard echos!!!!, and I couldn't help laughing even though it was expen$ive!! The explosions would turn oval mufflers ROUND, until my muffler guy installed some ancient huge glasspacks, then guys would hit the brakes when FIRE shot from the tailpipe!!! . The 2.2 was a buddy's that had several DEALER DEPOT level mechanics mechanics stumped about the hot non-restart. He eventually told me about the problem... and followed my instructions...
He called me 3 days later INCREDULOUS... he had waited 3 days to see if it would do it again... it didn't, so then he went to brag to the mechanics.

 

[outlawmws]

I vote for the coil first. I have had several do this, and seen others thsat did the same.

Quick test. next time it does this pour some water slowly over the body of the coil. (Avoid the wires...) If its the coil it will be cooled and fire and run for a short time.

 

[CarlV]

Next time it won't start take a can of carb cleaner with a nozzle and remove
a vacum hose around the throttle body or at least the plenum and give it a 5 second squirt. This will eliminate a bad fuel pump etc. if it still doesn't fire off.

A sprayer bottle with water works good on shorts to ground, leaky wires.
Obviously it is not in the computer controlled equipment as it is not setting the check light. Should be a "basic" issue.

Carl

 

[CarlV]

BTW, if you want to pop over I have a scantool.

:rofl:

Carl

 

[Eric H]

I'm going to guess with 106k on it that the fuel pump is dying when it gets hot.

CarlV's idea of squirting something flammable in the intake and seeing if it will fire is a good way to find out if it's a fuel problem.

If that works try having someone beat on the bottom of the gas tank with a mallet while you crank it (appropriate safety precautions apply here!), often that will restart a balky pump long enough to verify that it's the problem.

 

[WhiskeyRebel]

Carl, thanks for the offer but the scan tool would probably cost me less than the gas to drive from the middle coast (the Great Lakes TYVFM) to the west coast.

The motor doesn't appear to have a moving distributor, inductive or otherwise. Fortunately, the plugs are all accessible and the plug wires all go to a unit mounted in an accessible location on the top of the engine. I guess this would be a fixed coil pack. Anyway, it's right up where I can nail it with something to cool it off.

Would canned air or cool spray do the trick, or does it need water spray to cool it enough? I'm a little concerned about warping or cracking...something. I know that underhood parts have to be tested for thermal shock and hight-temperature water splash, but since I design auto parts, I also know how often test requirements get a "temporary" waiver because dammit we can't delay this launch date.

The plugs have been in for over 50K so changing them and the wires wouldn't hurt anything but my bank balance. The air filter and fuel filter and PCV rattler could also stand replacement. A guy at work recommended for me to feed a bottle of Techron through the tank, which I guess I'll do before changing the fuel filter so as not to feed the new filter a fresh clog.

 

[outlawmws]

SNIP
Would canned air or cool spray do the trick, or does it need water spray to cool it enough? I'm a little concerned about warping or cracking...something. SNIP.

The canned air or cool spray should do fine. Canned air comes out very cold So either one you have available should tell you something. :yes:

 

[kc8adu]

when it dies pull a wire,stick a plug in it,and lay it on the block.
have someone crank it.
btw some sensors like crank,cam can cause loss of spark and injectors.

 

[Strawman]

Since you say it's bogging and stalling, it sounds like it's fuel related. I had a Pinto many moons ago that had a filter on the pump IN the tank. What would happen, is the filter would get clogged from the suction, and after sitting for awhile, the crud would settle back to the bottom of the tank and start back up. Of course, the pick up was pretty low to the tank bottom, so the cycle would just continue. Just a WAG.

 

[CarlV]

The motor doesn't appear to have a moving distributor, inductive or otherwise. Fortunately, the plugs are all accessible and the plug wires all go to a unit mounted in an accessible location on the top of the engine. I guess this would be a fixed coil pack. Anyway, it's right up where I can nail it with something to cool it off.

On a disributorless ignition like yours, any primary igntion problems will set a code and turn on the check light. Spraying a mist is not going to crack anything that is not cracked already and is very good to pinpoint exact location. Anything affecting a single cylinder is not going to stall the engine
or cause it to not start.
Personally I would be looking at fuel pressureand/or relay if not in ECU (which would turn on light) first, a filter is possible, though not likely and flow is easily verified if removed carefully.

Carl

 

[markthefixer]

wow... I have got to get under some newer hoods.....

Somehow the computer has to tell what the engine timing/ crankshaft position is to fire at the right times....

But if the computer is not complaining about it's sensors.......

Maybe one of those test lights, the cheap things, looks like a pointed screwdriver with a bulb in it that draws a LOT of current (0.1 to 1.0 amps)and a ground wire. or whip up your own. Dvm's don't help because something could read 12 volts, but what it drives (when it is driving it ) pulls a lot more juice. try the coil PRIMARY wile it is running/cranking then when it starts balking do it again.

Will it do it if you let it idle at home???? not that you have to trounbleshoot somewhere out in the wild....

Good luck, keep us posted as to what does/nt work....

 

[Carmine]

Have u considered vapor lock, given this hot streak we are running?

Also, you can get codes from your computer by tuning the key on/off/on/off/on (not start) then the CHECK ENGINE lamp will blink out a morse code-like diagnostic code. I'm sure you've got a code there someplace. Most codes do not turn on a check engine lamp by themselves.

Read this:

http://allpar.com/fix/codes.html

As for that whole "magent wearing out" theory... Hogwarsh. The cam/crank sensors on most every car made for the last 20 years are all Hall Effect switches. They last for years, or millions (billions?) of cycles without failure.

The primative people of the 1970s didn't want to be bothered finding out how something like a computer worked, so most of them just dismissed the Lean Burn System as "evil", and ripped it off the car, replacing it with the traditonal system.

Of couse it suffered the faults of low processor speeds and all the Rube Goldberg-like electromechanical devices, but the whole idea behind Lean Burn was to minimize pollution and fuel consuption by using both the igniton system and the carb to keep the engine running at stoichiometric, or leaner during cruise.

Guess what? Your new car does the same thing, except with the benefit of fuel injection and better computers. Think anybody gives props to Chrysler for pioneering this? Nope... Just a lot of BS urban legends.

 

[markthefixer]

I agree about reading the codes... and I have stated that I need to get familiar with what is under the hoods of newer cars.. post 96 is my aim... cuz you can hook up to a laptop and let the computer spill it's tale of woe...
But electronics basics and engineering basics DON'T change.

In defense of my last post:

I mentioned the lean burn system only because I was ( and am, 79 Cordoba 318 2BBL Lean Burn @ 35K miles) able to keep them running when experienced dealer mechanics recomended replacing the distributor, carb and computer with an mopar aftermarket performance setup. I'm glad I didn't because Illinois emissions laws would have stranded me a few years later, no way to restore factory emissions condition insisted on by law.

I am a really obsessive cheap b*&^$#d and will work(fool) with something long past the patience of others before replacing parts.... and I was setting magnetic gaps and checking distributor shaft runouts for mechanical faults long before I got the replacement coil/magnet assy's (yes... EACH time except the buddy's2.2L charger).

THEN:

I SCOPED the running output of the sensor FROM the passenger compartment WHILE driving the car(s) for (usually) over a week, before and after replacement.. (I kept the harness,had the scope, so why not use it)
I saw the sensor output drop under heating conditions, and the difference in output of the new sensor when it was replaced, and also IT's performance under heat.... Spraying Circuit Cooler into the distributor when it died fixed it...for a while....
So either the magnet lost strength, the reluctor's magnetic properties changed or the coil's properties changed (perhaps the pickup coil was shorting out under heating BUT it wasn't a sharp drop, it was more of a gradual decline) with prolonged engine heat.

I also have an engineering background so I want to be able to fully research the fix.... i/e failure analysis ...... or ...... why did it fail?

Remember the truck commercial a few years back where they were driving and displaying on a oscilloscope the interior noise level from a microphone on the dash?? not only did I do it MANY years before, but they used the EXACT same oscilloscope I did.... (a tektronix 465/475 with option #7, 12 VDC operation, and I also have an HP 1726 oscilloscope that runs on 12 VDC too....).

 

[dgwojo]

Yuk, breaking down on the autobahn (I-696)!! I had a Dodge Dynasty that gave me similar troubles, first time it was the in-tank fuel pump, if I rocked the car by hand it would get the pump going again, second time was the BMAP sensor, although that sensor let it start and have a surging idle. Personally I'd start with a Crank or Camshaft position sensor if you're getting good fuel pressure, they can wreak havoc, good luck, Dave.
:scratch2:

 

[Carmine]

the coil's properties changed (perhaps the pickup coil was shorting out under heating BUT it wasn't a sharp drop, it was more of a gradual decline) with prolonged engine heat.

This is what I'd go with. The coils can break down.

Also, I don't think that '79s were still "Lean-Burn". True Lean-Burn systems used a dual magnetic pick-up distributor, one pick-up was for start/warm-up, and the other was for "run". Eventually as computer power improved, they switched to one pick-up and the computer changed timing on it's own. This system was simply called "Chrysler Electronic Spark Control", because lean-burn had made such a negative impression. I think this system continued through the 1989 M-bodies (5th Ave, Diplomat, Gran Fury). By 1990, every engine was EFI.

Did you know that 1976 F-bodies, (Aspen/Volare) were originally supposed to be Fuel Injected? Wouldn't have believed it myself, if not for seeing the original engineering documents. The original Dodge Charger (1966) was supposed to offer an optional Turbine engine, in fact there was change made to the firewall stamping at the last minute to accomodate some part of the turbine engine package. The same thing almost happened in 1980 with the Dodge Mirada, and you'll notice that the car has a number of "turbine" styling cues. The plan was dropped as the company needed to cut costs and risk.

 

[Chad Hauris]

We have an 86 Dodge truck at the shop which has the dual pickup coils, one for start and another for run...however there is no computer to it that I can see...it uses a 4-barrel Rochester Quadrajet carb. You have to let go of the key off of the "start" position before it will start though so I'm thinking the start pickup is bad or there is a problem in whatever device such as a relay switches between the two coils.

What kind of FI were those 76 Chrysler engines to have, was it TBI or multi-port? Someone I know had a 1977 Cadillac Seville with a 350 engine and multi-port fuel injection and I think it was too far ahead of its time, he could never get it to work right.

 

[Carmine]

The system of fuel injection they used eventually debuted in the 1981-83 Imperial. It would have been closest to a TBI system, but actually didn't use injectors. Rather a "fuel spray bar", a kazillion sensors and an underhood pump that stepped up the pressure from the in-tank fuel pump.

The system does work, but you really have to have a love for the car & electronics to KEEP it working. (I had one that did work ) Same goes for your friend's FI Caddy, or those V-4-6-8 engines. In fact, I painted a 1980 V-4-6-8 Caddy that ran perfect back in about 1994. Even took it out on the X-way just to play with it a bit... Just wanted to see if I could feel the cylinders drop off (It also had a digital display of active cylinders on the dash). Pretty neat to see one that worked... Oh yeah, did I mention the guy had an advanced level degree in mechanical & electrical engineering and did all his own service??? :lmao:

It's like watching a 21" roundie... Lot's of bother and adjustments just to use something that is antiquated! It used to be that innovation was rewarded, but in our global economy, the third-world copycats just sit back and wait for the bugs to be worked out, then clone the finished product and bang them out with slave labor.... Like the aforementioned color TV.