car starts, then won't start

[mcglsr2]

hey all, here's my issue (oh, and the car is an 87 CSX):

if the car is cold, it will start up and idle just fine. i think the longest i've let it idle is like maybe 30 min. i let the engine/engine bay get good and hot. then i turn off the car, then immediately try to restart it, and it won't. it just cranks and cranks, but never catches.

i haven't been able to verify yet, (but this has happened before), i'm willing to bet there is no spark. i need an extra set of hands to confirm this, and i just don't have them right now. i've replaced the coil, so i know that's not the case. i haven't set the timing yet, but i know it's not too far off from 12 deg. and the car is getting fuel, the plugs smell like gas if i try to start it a couple times then pull them.

it's almost as if something gets overheated and doesn't want to work, thus the car won't start. i'm thinking maybe power module - except that the one i have in there is maybe a year old at the most.

any ideas? thanks all

[turbovanman²]

My bet is on the HEP

Any codes?

[mcglsr2]

dang it, always forget the codes. no codes thrown (other then 12, but that's expected).

you think it could be the HEP? i think i have a spare that i can try. will a bad HEP cause the car to die? that hasn't happened yet, just wondering.

[turbovanman²]

Of course it will cause it to die, no signal, no start and they don't always throw a code.

[mcglsr2]

hmm, car hasn't died yet the first time i start it. it just won't re-start. i'll head out to the garage and try it out.

[Shadowv4l]

When its not starting, pull a spark plug and place it against the block while crankin it (dont fry yourself), look for spark.
Next check for fuel psi, got a fuel gauge?
or what you can do is find a can of 2+2 gum cutter and spray it in the throttle while cranking, the car will start and as soon as you stop spraying it will die, this is an easy way to see if you have fuel.

[mcglsr2]

okay, so i swapped the HEP out with a spare one, no love. car didn't start. for what it's worth, the HEP i have in the car right now is a napa echlin part - that doesn't mean it won't fail but it is one of the napa quality parts.

right now i'm thinking power module...

[Shadowv4l]

DO NOT USE BRAKE CLEAN! IT WILL CREATE MUSTARD GAS!
just speaking from experiance

[mcglsr2]

lol, well i already did interestingly enough, when i started the car for the first time, i got me some smoke. perhaps that's what it was...

well, i'll keep that in mind for next time. is there any reason that would cause me trouble? it will burn off, right?

[Shadowv4l]

well, it can burn your lungs for some time and feel really uncomfortable, and i noticed when it hit the floor out of the exhaust it started to screw up my concrete garage floor in that spot. As far as hurting the car I doubt it since the gas was created on the way out the exhust pipe, you may have cleaned your intake valves, LOL

[thefitisgay]

well, it can burn your lungs for some time and feel really uncomfortable, and i noticed when it hit the floor out of the exhaust it started to screw up my concrete garage floor in that spot. As far as hurting the car I doubt it since the gas was created on the way out the exhust pipe, you may have cleaned your intake valves, LOL

so thats why my lungs burn?

[mcglsr2]

alright, time for an update.

to summarize the issue: if the car is cold, it will start. it idles fine, i can drive it around, no problem. after it gets hot, if i turn off the car, then try to turn it back on, it will not start. this happens when the car gets hot. also, once the car is running, it doesn't seem like it will shut itself off. it seems to run just fine. it's idled for 30 min or so with no trouble. ran fine. only after i turn it off and then try to restart it, does it not start.

i have replaced the coil with a new unit, i've replaced the power module with a new refurb. unit. i checked the HEP with another one that i have. none of these changes affected the car - it still wouldn't start. NO codes are thrown.

so the car not starting has to do with heat. something is getting overheated and then keeping the car from starting. but if the car is already running, it seems to run fine.

what could cause this? i'm pretty certain it's not getting a spark when i try to restart it (but it doesn't seem to be missing once it's already running). i was thinking: could it be something in the ASD? it seems to be something that lets the car start just fine when cold, but when hot, will not let the car start. it seems to have no effect once the car is running. could the issue be a fusible link?

any ideas?

[Mario]

Sounds to be me like a fueling issue. The car will start-up cold because it has sufficient fuel. When the car is hot, more fuel is required in order to prevent the fuel evaporating before it hits the cylinder. Do you have a custom cal? If so, you need to get the fuel start tables redone.

If it has a stock calibration, you could start with checking fuel pressure.

[mcglsr2]

interesting idea. yes, i have a custom cal, and i have 72# injectors in there. i have adjusted the fueling tables using zChem - are you suggesting that i need to adjust some other tables? can you tell me which ones?

if i crank the car a couple times when it's hot (and therefore not starting), then pull the plugs, i can smell fuel on the plugs. do you still think it's fueling?

another test would be to try a "stock" MP cal - it will be super rich (i wonder if it will even idle), let it get hot, and then try starting it again...

[mcglsr2]

bump. anyone, any ideas?

[87glhs]

Well, first I'd redouble-check the timing while it's hot, and temporarily put in a fuel pressure gauge. If you're ok on those and it still won't start then I'd suspect the logic module may not be giving you a good startup mix of fuel/timing.

Other question--once the engine warms up, are you able to drive it? I've seen a couple of cases where the engine idled great, and then stalled as soon as it was put under a load.

Also, how's your mechanical timing? Are you using an adjustable cam gear?

[cordes]

If the hep was bad it shouldn't have fuel wetting down the plugs.

I doubt it is a dieing pump because I don't think the hot start operation would be that reliably bad. I would second the notion of hooking up a FP gauge though as it would be the first place I would start still.

Have you gotten the car to run with this cal without dieing when hot before? If not I would strongly suspect the fuel start from coolant temp table.

[minigts]

It sounds EXACTLY like my 2 piece swap. Had a 1 piece and the car started fine all the time. Got the 2 piece on and it will start cold, idle fine. Turn the car off and it will take FOREVER to crank. Once it cools down, it will start ok again. Cordes, Bucar, DodgeZ, badandy and others have witnessed this firsthand.

[mcglsr2]

okay, i think i found the issue, and Mario put me on to it. Cordes & 87glhs, i think you are heading in the right direction too.

Well, first I'd redouble-check the timing while it's hot, and temporarily put in a fuel pressure gauge. If you're ok on those and it still won't start then I'd suspect the logic module may not be giving you a good startup mix of fuel/timing.

i just checked the timing. it's set at 12 deg right now. i didn't check the fuel pressure though, that's something that i could do. logic module being the issue, +1...

Other question--once the engine warms up, are you able to drive it? I've seen a couple of cases where the engine idled great, and then stalled as soon as it was put under a load.

yah, i can drive the car with no problems. i haven't tuned it or anyting since putting on the ported head, so i didn't do any aggressive pulls or anything, but i drove it around the neighborhood with no problems.

Also, how's your mechanical timing? Are you using an adjustable cam gear?

it's where it should be as far as i know. i just recently set all that. the only change from before is that the cam (i think) now has 5 deg retard built in - it's a 93 TBI roller.

If the hep was bad it shouldn't have fuel wetting down the plugs.

I doubt it is a dieing pump because I don't think the hot start operation would be that reliably bad. I would second the notion of hooking up a FP gauge though as it would be the first place I would start still.

i will check the fuel pressure. it's easy enough to do, and it would be worthwhile to see what it is.

Have you gotten the car to run with this cal without dieing when hot before? If not I would strongly suspect the fuel start from coolant temp table.

no, i haven't. brand new cal, because of the 72# injectors. and i know think this is where the issue is. i think something is off in the cal. and what i just found out i think only reinforces the cal being the issue.

here's what happens: i just got done timing the car, then turned it off. it didn't run quite as long as i had let it before. i tried to restart, and it sort of almost did, but not quite. i was like "hmmm..." so i got in the car, tried to start it again, and pumped the gas pedal. and it started. i turned it off, and tried again. same thing. i pumped the gas, and it started. logic module being the issue, +1000...

so this is the first time the car has 72# injectors, AND it's now a ported head. so the consesus is that the table in the cal is off, correct? and the culprit table would be the fuel start from coolant temp? if so, i need to add a little more fuel? just out of curiosity, would larger injectors and ported head cause this? and i assume that table is not scaled with zChem (or not scaled enough)?

thanks for all the help so far. without you guys, i would be dead in the water so many times...

[mcglsr2]

It sounds EXACTLY like my 2 piece swap. Had a 1 piece and the car started fine all the time. Got the 2 piece on and it will start cold, idle fine. Turn the car off and it will take FOREVER to crank. Once it cools down, it will start ok again. Cordes, Bucar, DodgeZ, badandy and others have witnessed this firsthand.

did you ever get this resolved? or is it still and issue? the car drives around just fine, right? it hasn't died on you?