No Start Issue

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Mcfarlrm

Mcfarlrm

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Need to chase a no start issue. Intermittent on cold start and always present after running and trying to restart. All accessories have power along with MSD ignition. Bridging the battery and starter cable on the relay starts the engine ever time when the issue is present. What should I be checking to narrow down the culprit?
 
Auto or manual trans?
When you say no start does it mean no crank?
Have you tried moving shifter some when trying to crank or shift to neutral to see if will crank.
Do you have a ground strap from engine to firewall with clean connection?
More items to check if this doesn't help.
 
I always start at the battery cables, then the second thing I check is the bulkhead connectors.
 
Assuming the Transmission linkage is grounding the TSS, as per post #2; then;
I always start at the battery cables too, lol, but then I move to the relay, sending battery voltage, from the battery to it, and grounding the transmission side, back to the battery negative, or the block. If it cranks, it's good.
And next would be the bulkhead connectors followed by the connections on the back of the Amp gauge, but, since it cranks by shorting the relay, that last one's a stretch. .
 
No crank. Auto trans and checked in both park and neutral. Ground strap, battery cables and bulkhead connectors good.
 
Yes, spark and fuel. Curious if something is going on with ignition switch itself.
 
Mcfarlrm said:
No crank. Auto trans and checked in both park and neutral. Ground strap, battery cables and bulkhead connectors good.
Click to expand...
WHAT ARE we working on?

Start with the start relay and start circuit. The start relay interacts with the neutral safety switch to not crank unless the trans is in P or N. But linkage can go out of adjustment, the switch can go bad, or you might have a wiring issue. Start by looking at the start relay, the two 'push on" flag terminals. One should be yellow, and is the start wire from the ignition switch. Those terminals are the relay coil, the remaining one goes down to the neutral switch and grounds in P or N. So first unhook the trans wire, and clip that relay terminal to ground. BE CAREFUL as you have now bypassed the neutral start protection. Se if it cranks reliably, go from there.

If not, see if you have power on the yellow wire. Maybe there's a poor connection through the bulkhead connector, etc, or even at the ignition switch connector, or the switch itself.

LISTEN if it won't crank and see if you can hear the start relay click. Sometimes this takes two people. It could be bad.

If the starter cranks when you short across the two large terminals on the relay, the trouble is right there in the relay/ relay circuit/ neutral switch/ wiring
 
You have spark and fuel and it won't start ? The only time I have seen that is when a timing chain has skipped some teeth.
 
Murray said:
You have spark and fuel and it won't start ? The only time I have seen that is when a timing chain has skipped some teeth.
Click to expand...
I don't know. First he said "it won't crank" and now he's talking about it has spark. ?????
 
DEFINITIONS......

"CRANK". This does NOT mean that the engine "cranks up and runs." "CRANK" means that the starter motors and whirs and engages the flywheel and rotates the engine, whether the engine fires, runs, or sits there and rotates from the power of the starter

"FIRES" This means the engine coughs, belches, pukes smoke out the exhaust, and attempts to run, or possibly continues to run, It may die almost immediatley or not

"FIRES AND RUNS" Self explanatory
 
Won't crank from key ignition. Cranks and starts by shorting relay.
 
Found the issue. The safety neutral switch had a loose wire within the connector that connected to the relay. Another concern that I have noticed however before this issue presented itself: On cold start, the engine fires right up with a strong crank. At temp and when it has been sitting for bit, the crank is a bit slow and struggles to fire. If I short the relay at this time, strong crank and fires right up. Could this be a heat soak issue somewhere?
 
If you short the relay contacts & the engine cranks ok, it suggests the contacts are worn/pitted. Time for a new rlay.
 
Probably not it but check your timing. I had a thread going a while back with an issue where I could intermittently get the engine to fire up with the key but normally it would slow crank. If I jumped the starter relay, it always cranked over fast. Turns out my timing was too advanced. Backed it down and the problem went away thanks to the experts here.

I know you say it only happens when the engine is warm but there is a slight chance that it's a coincidence. Wouldn't hurt to check, plus it's free.
 
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