[Interceptor]

So I've developed a new problem since installing a Sniper EFI -- the starter drags when the engine is hot. This never happened with the QJ. What could have changed? Extra current draw somewhere.

I've tried the usual fixes --heat shield on the headers by the starter, checked the starter cable and battery connections etc etc.

Thoughts?

[TCSGTO]

Are you controlling the timing with the Sniper? If so can you retard it at cranking speed?

[Interceptor]

No, HEI.

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[Schurkey]

Originally Posted by Interceptor

the starter drags when the engine is hot.

What do you mean by "drags"?

Doesn't disengage from the flywheel--grinds when you release the key?
Cranks slowly?
Something else?

What kind of starter? 10MT, non-GM mini-starter, GM PMGR?

How is it wired? OEM wiring? Solenoid-on-the-fender?

[Interceptor]

Barely turns, or not at all. Stock rebuilt starter and new stock engine harness for HEI.

Again, never did this with the carb. Something new with the EFI. System relay is wired to ignition at fuse panel under dash, and the main power lead is run directly to the battery.

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[johnta1]

How is the the starter wired?


Battery cable to starter?
Ignition Start switch wire to the starter solenoid?

[Interceptor]

Yes

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[Schurkey]

First Guess: It's a starter problem, not a FI problem.

Diagnose it like any other starter/battery/charging problem.

[hal101]

yes it sounds like a starter prob but i would try disconnecting the HEI next time you have this prob and just see if it cranks better

[jamaca85]

Maybe ignition switch...check the wires coming out to make sure your getting 12v...out...to starter..before replacing the starter

[tc]

As stated above, when you check for 12 volts on the solenoid wire , check when you turn the key with the wire loose and hooked up to the solenoid. I have 12 volts when the wire is not hooked up and 5.7 volts attached to the solenoid when I turn the key. When I bring 12 volts to the solenoid from a different wire ( not the factory wire ) the starter works fine.

[jonmachota78]

Check with a known good battery too

[Schurkey]

Originally Posted by tc

As stated above, when you check for 12 volts on the solenoid wire , check when you turn the key with the wire loose and hooked up to the solenoid. I have 12 volts when the wire is not hooked up and 5.7 volts attached to the solenoid when I turn the key. When I bring 12 volts to the solenoid from a different wire ( not the factory wire ) the starter works fine.

Low voltage/high resistance on the wire to the "S" terminal can cause "No cranking". It won't cause "Slow cranking".

[sdbob]

Use to have problem on my 421 back in late 60s,starter bushings wearing egged.Bought necessary tools and bushings,replace them now.

[Interceptor]

All good suggestions. Remember that the condition is only when the engine is HOT and then been standing a couple of minutes. If I cool it off for 15-20 minutes away she goes.. Sounds like standard starter heat soak. My starter guy (who sold it to me rebuilt, that's his Business) says the starter itself tests out 100%.

So, must be the heat. Millions of guys have headers next to their starter and make out fine, so why is this one acting up ... ONLY since installing EFI? Makes no sense.

I'm thinking of changing to RARE manifolds anyways for ground clearance, but I ran across a set of Tribal Tubes locally and was considering them. LOVE the sound of headers! However, don't want to bite that bullet only to find that header-caused heat soak is the issue.

[Schurkey]

Originally Posted by Interceptor

Sounds like standard starter heat soak. My starter guy (who sold it to me rebuilt, that's his Business) says the starter itself tests out 100%.

Sure. Sounds like standard heat soak to me, too. Did he "test out" the starter at elevated temperature? I bet "no". I would put a starting/charging system analyzer on that vehicle when cold, measure the starter amperage draw along with battery voltage while cranking. Then drive the thing so that it's fully-warm and would tend to act heat-soaked and slow-cranking. Connect the gauge, measure the amperage and voltage hot. Compare the two readings.

Originally Posted by Interceptor

So, must be the heat. Millions of guys have headers next to their starter and make out fine, so why is this one acting up ... ONLY since installing EFI? Makes no sense.

More-precise control of fueling (and ignition timing???) makes for better combustion, less misfire or excess fuel that might cool the combustion.. Better combustion makes for hotter exhaust? Hotter exhaust brings out heat-soak problems in the starter?

You're better off to treat it as a starting-system problem and not a fuel-injection problem. Don't get carried away, or blinded to what is actually happening. Diagnose this as a starting issue, solve it, and move on. Even if the FI has something to do with the heat soak--and I'm not saying it does--the starter must have been right on the edge of heat soak before the FI.

So even if you "fix" the heat-soak problem by, let's say, advancing the timing five degrees or adding additional fuel to the FI programming which might cool the exhaust a little, you still need to do something with the starter to shield it from the heat, so that the fuel and ignition can return to their optimum values. (assumes that the fuel and ignition are at or near optimum values now)

[DOC]

Is your electric fans coming on when trying to start? If so you could be losing voltage if they are running while it is cranking. Especially if dual fans running on just 1 relay. The fix is to close the relay in run mode but not start mode.

[Tim Corcoran]

Does the engine run hotter with the EFI than it did with the Q-Jet, if yes that would explain why it is harder to start now than with the Carb as higher temps require more cranking power. If there were no changes to ignition timing then it sounds like it may be running a tad hotter with your EFI. If this is the case there are a few things that can be done to improve the starter system. You can install larger size battery cables, install a ford style starter solenoid, and/or a gear reduction mini starter. Make sure your ground wire is large enough and has a good connection. I run one ground from the battery to the frame and another from the frame to the engine using size 01 welding cable. I also use 01 welding cable on the positive battery cable to the ford style solenoid then wire from the solenoid to the starter and jump the start wire on the starter solenoid to the main cable.

[Interceptor]

Doesn't run any hotter, same T-stat and electric fan with turn-on at 195. I'll have a look at those wire sizes.

[Interceptor]

Originally Posted by DOC

Is your electric fans coming on when trying to start? If so you could be losing voltage if they are running while it is cranking. Especially if dual fans running on just 1 relay. The fix is to close the relay in run mode but not start mode.

Hm. Good one, I'll have to check that.