'94 DI 5spd hot starting issues

[scottsdalerrc]

So we have a 94 DI that starts just fine cold, once its hot it will not start at all. barely even cranks.
i know this has been discussed before but there didnt seem to be any type of resolution.

anyone have any thoughts? we were considering redoing starter wiring to begin...

 

[antichrist]

While redoing starter/battery wiring is always a good idea on D1's IMO, that's very unlikely to be your real issue. If it's electrical the most likely culprit is a failing ignition module that's mounted on the side of your distributor. A search will turn up not a few threads on it.

 

[singingcamel]

Amp module .

 

[robertf]

so it won't crank and you guys think its the ignition module?

clean terminals, check starter and battery

 

[cosmic88]

If the starter seems bogged down (you said it barely cranks) then your batt and or cables and all connections are suspect. Tom (antichrist) has a great picture of a cable that looked decent but when the insulation was peeled back the entire cable was badly corroded.

If it cranks well and starts but is having running issues then you could be looking at the ign. module as has been said. Has your ign. module been moved to a remote location or is it still mounted to the dist.?

Slight possibility it could be the fuel temp sensor but usually that just makes it run like crap for a few seconds at startup. The ECM uses it for hot start fueling control... without the FTS within the correct ohm range it'll overfuel at hot startup. that's a simple ohmeter test...

 

[scottsdalerrc]

no, afaik the ign module is not moved.
and like i said, it'll start right up in the morning or after sitting for an hr but once warmed up-shut it off and it will not start.
Batt is new.

Thank you all for the info-gives us a few things to check out. I'll report back with our findings.

 

[antichrist]

barely even cranks.

Don't mean to be insulting, but do you really mean it doesn't crank (starter barely works), or that it doesn't fire?

If the starter is barely working (won't crank) then robert is right, it's not the module.

 

[scottsdalerrc]

you're right, poor wording. At this point (as of yesterday afternoon), nothing. no attempt, no click..nothing.

looks like we may be trailering to MAR.

 

[antichrist]

No, wording was fine if you really meant it didn't crank. But some people say "crank" when they really mean it won't fire.
Sounds to me like you have a really bad ground. Or a really dead battery.

 

[singingcamel]

Sorry , I doubt its the ignition module, I'd clean up and check all starter connections..clean battery end cables. i'd bet its the starter..

 

[scottsdalerrc]

and the batt is less than 4 months (iirc) but if its not the starter, its that bosch batt.
may have to grab a donor for now...will possibly look into it more this coming weekend.

 

[scottsdalerrc]

No, wording was fine if you really meant it didn't crank. But some people say "crank" when they really mean it won't fire.
Sounds to me like you have a really bad ground. Or a really dead battery.

oh, no it definitely does not even crank.

 

[jhmover]

I just had a similar problem. Not always when hot but when it's hot out it was puking.Thought I had a short but none could be found when I finally checked. Turned out my 3-4 month old Optima Yellow top is crap. I put a Odyssey back in and no more problem so far.

 

[scottsdalerrc]

well, this truck has been sitting a while and we're looking to get it back up and running for the rallye's coming up so...
Same problem persists. Starts fine cold, once hot and it shuts off, it will not start. no crank, single click from the relay(s) under the hood. Batt is a week old, alternator and starter have been replaced. batt terminals are clean and connectors are new. 100a Alt fuse is new (was looking shitty and had low readings on batt while running).

Starts up great in the morning (cold), run it 20 minutes down the trail and shut off. It wont start for maybe a half hr. but then it'll crank right up like nothing happened. fuel temp sensor?? i'm at a total loss here. gonna grab a fuel temp sensor today or tomorrow from the old engine and see if that helps.

thanks
-Brian

 

[jafir]

Do you get power to the starter when it doesn't crank?

 

[antichrist]

Is it still that the starter motor doesn't respond normally when the engine is hot?
If so, sounds like heat soak, especially if the heat shield isn't there, and it won't have anything to do with fuel or ignition.

 

[scottsdalerrc]

Havent been out to check this in a day so i've no answer for you at this time Jafir.

Tom, that what we're unsure of. I really dont think its the starter, its been replaced twice since this thread was started 2 years ago. We tested the one thats on there and its good (as was the one we pulled).

 

[antichrist]

Time to get out the circuit diagram and start tracing to find where the point is where low/no voltage/amps occurs. Do you have the ETM?

 

[scottsdalerrc]

so we spent saturday continuing the troubleshooting here based on some input here as well as some discussions with Trevor.
Testing voltage at batt (replaced again saturday as the bosch had died again), tested at Alt (engine on and off). both were good

Tested voltage at starter relay in kick panel at hot side as well as ignition side during crank. All seemed correct there (i found it odd that the voltage rapidly drops as soon as the test probes are grounded). Also swapped in the relay from a working D2 with same results)

Voltage at coil is good and spark is good.

ran truck for 20 minutes around the farm, came back and shut it off. wont start.
tested voltage immediately at starter relay, seems to be the same. tested voltage at starter, seems good. starter is knocking on ignition, just not cranking. We were able to duplicate this 2 more times (after it sits for 15 minutes, it'll start right back up again).

Of note, the starter solenoid becomes extremely hot after running, moreso on this truck than on my '95. possible issue? the heatshield is there though.

Have a rebuilt starter we're going to swap in this week. Just wanted to keep the log here incase anyone has any other input.
Thanks to you all and Trevor...hopefully it'll be rally ready in time.

 

[ptschram]

Rebuilt starter... Two small lugs on the solenoid or one?

When it's hot can you crank the engine by hand with same resistance as when cold?