Ok so my 1990 240 has an intermittent hard start. It usually happens ONLY at the first start of the day. Usually when wet and cold.

Edit- spraying water on wires at night revealed shorts to ground. New bougicord wires fixed it! I try to run only bougi! The blue ngk wires had over 70k though.
New cap and rotor prob helped too. Old ones were getting pretty crusty. Amazing how much low end power and throttle response was gained too!









In the past I have had a no spark from coil. Other times it would spark, but no start.

NOW the problem consists of an intermittent hard start. While cranking, it backfires a bit and I can pop start the car OR crank excessively and it starts.

I plan to get a 1993 fuel rail with shrader valve to see if there is an issue with fuel pressure 'draining' after sitting all night. Swapped check valve with different USED one made no change.

 

the LH 2.4 cars (89 and forward) should run the fuel pump for about one second when you switch the key on, that should be sufficient to develop adequate pressure to start.

does this car get damp inside? our 87 got really wet when it spent a winter on the north coast of california where its perpetual drizzle... and became quite erratic. talking the kind of damp that had condensation all over the interior of the car to the point it was starting to get mildew on the inside of the glass. We got it back home here on the central coast, dried it out over a couple sunny days, and it ran fine again.

 

It has small windshield leak on driver side.

It happens when its dry out too.

A pop start gets it going and it completely goes away for the day.

It backfires and makes the starter work real hard sometimes. even to the point where the engine wont turm and you have to start a new crank. Killed the batt real fast this morning.


I have even been looking at engine and seen it diesel a minute later.

 

Symptom is backfires when cranking and it will slowly start running with the starter and eventually come to life.

 

huh. backfire and hard to crank suggests a mechanical issue, assuming the battery and starter motor and wiring are good... I'd do a compression test all 4 cylinders, and verify the timing belt hasn't slipped a tooth, and that the crankshaft and intermediate shaft and cam shaft all line up with the proper marks when rotated to the right place.

 

Verified timing.

Car runs great once you have gotten past the ocassional hard start in the morning.

Going to try spraying water on plug wires in the dark to look for shorts. Might try some fresh bougicord wires.

 

This has been going on for six months. Tweaked the hood in an accident rain got under hood. I figured it was just a wet cap, but that never fixed it.

Like I said, the spark used to not be at the coil wire intermittently, but now its has turned into consistent spark , but backfiring during cranking. I have verified fuel spray during these no starts in the past.

In the past few years I have owned the car there was also an intermittent 1-4-4 code for signal missing from LH. That didn't accompany these no starts but rather a short sputter on accel and a CEL but I could always clear code and didn't have any serious driving or starting issues. I did fix a bad fuse at battery though. This was just some background info on a gremlin that could be/have been totally unrelated.

At this point I need my car to start reliably so I don't have to park on a hill or get stuck at some ugly girl's house some wet morning! Jk

 

Possible progress! Took a spray bottle to it my 60k+mile blue NGK wires and saw tiny blue sparks tonight grounding on the PS pump. Looks like its time for a new set of Bougicord wires.

Backfiring to me says lean or ignition problems. I have had my share of getting a fireball backfire to the face leaning above a carburetor and dialing in distributor timing on other engines. Been shocked plenty of times too to know that it hurts and pisses you off pretty well too.

Anwyays, gonna put some new Bougicord wires on there and hope for the best.

 

Failure! Well, failure of spark that is! After my spray test the engine would not start. It has the exact symptoms of my cold or wet NO starts; excessive cranking with backfiring. The car also ran like poop and would die until it dried out.

I believe this also explains why I had intermittent spark for my tests. My test was unplugging coil wire from dist and then grounding it at strut tower. The wire was bent out of contact of metal for this test INTERMITTENTLY. Its my theory at least.


Not a dollar fired from the parts cannon! I lied...kinda....I did toss a crank sensor, ICU, and main pump at it with no luck, but they were sitting on my shelf.

I am just glad it is not my harness. I already have the oil pressure wire and stimulator wire rewired hanging across to the fender due to oil rot at the bottom of the harness.

 

i'd suspect the power module next.

1) put a 12V test light between coil pin 1 (-) and 15 (+) and crank the car, does the test light blink?

2) unplug the power module, and connect said test light between pin 5 (-) and pin 4 (+) on the harness plug, crank the car, does the light blink ?

if the answers are (1: No, 2: Yes), then your power module is bad. if (no,no) then the problem is upstream (ICU, crank position sensor, etc). if (yes,yes), then I'd be looking at the coil, wires, and distributor if you really have no spark.

 

Freshish power module and have always had switching at coil I think...

 

I don't use test lights. I use my multimeter.

 

meters aren't so great for seeing pulses.

 

Very true.

 

With a fresh set of bougicord wires and a fresh bosch cap and rotor, my 240 now appears to start in humid, wet, or cold weather!

 

ah, if it was always that simple.

 

Yeah the slow crank is the battery of course. There was a small relationship between the two problems, though. When the car would backfire and start hard it really strained the poor 3 year old walmart battery and it may have put it on its final legs. Still get slow cranks most the time. Meh, whatever. I just pop start it if I really need to. Has worked for now....