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L98 only starts w/ starting fluid, but runs fine, and starts fine after running...

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Old 05-22-2007, 05:13 PM
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Car: 1981 Chevy Malibu, 1987 Formula 350
Engine: 229 V6, L98 TPI 350
Transmission: TH350, 700R4
Axle/Gears: 10 bolt ???, 9 bolt 3.27 posi
L98 only starts w/ starting fluid, but runs fine, and starts fine after running...

what would cause an L98 to not start on its own until its run for a minute or two?
Basicly the car only starts if I squirt starting fluid into the TB, it runs fine, idles fine on its own, and if I let it run for a minute then shut it off, i can start it up on its own up to like 45 minutes later no problem. After that it needs starting fluid again. Any suggestions? engine is stock except for hedman long tubes and a DIY cold air intake
-Chris
Old 05-22-2007, 06:25 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

I'm gonna take a flying leap here :-)

Check the cold start switch and injector.

Start from there

later
Jeremy
Old 05-22-2007, 06:36 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

fuel filter ??? when was it last changed ? if you dont know , change it . they are cheap , easy to change . hope this helps .

uncle tom
Old 05-22-2007, 08:54 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

I had the same prob on a 89 305 the prob was the fuel pump it didn't have enough pressure to give the enitial startup but it would run fine and start fine until the engine cooled off. I have no expirience with the cold start injector setup since 88 was the last year for that, but it could definatly be your prob.
Old 05-22-2007, 10:55 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

coolant temp sensor?
Old 05-22-2007, 11:07 PM
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Car: 1981 Chevy Malibu, 1987 Formula 350
Engine: 229 V6, L98 TPI 350
Transmission: TH350, 700R4
Axle/Gears: 10 bolt ???, 9 bolt 3.27 posi
Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

Originally Posted by Justin89Formy
coolant temp sensor?
I'm curious to know why this would cause this problem..... When I first got the engine running again (With the major vacuum leaks), the headers burnt the wire from the temp sensor in the pass. side cyl. head, but I figured that it would just render the temperature gauge useless/inaccurate
Old 05-23-2007, 10:34 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

coolant temp sensor in the front of the intake. if its bad and tells the ecm its really cold out, it would make the car run so rich at startup, that the car may not start. Common tpi problem
Old 05-24-2007, 08:19 AM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

Sounds like a TPI transplant. Make sure your ECM and injectors have ignition power with the key in crank. Sometimes this is overlooked and there is ignitition power in key ON only. With no ignition power in crank, the ECM never pulses the injectors and the injectors have no chance of firing.

Good luck
Old 05-24-2007, 08:40 AM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

Are you getting any injector pulse during cranking?

You might also look for 12v at inj harness during key on and cranking. If present during both situations look for voltage drop. When inj get hot they tend to need more power to overcome the increase in resistance.
Old 05-24-2007, 11:45 AM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

Also you might want to check the ohm reading on the injectors.
Old 05-24-2007, 05:54 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

Originally Posted by 89 Iroc Conv.
I had the same prob on a 89 305 the prob was the fuel pump it didn't have enough pressure to give the enitial startup but it would run fine and start fine until the engine cooled off. I have no expirience with the cold start injector setup since 88 was the last year for that, but it could definatly be your prob.
I agree, I had same deal, check your fuel pressure, should be at least 41psi.
good luck
Old 05-24-2007, 07:11 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

HMMMM.Well, My stab at this would be the fuel pump relay/oil pressure sensor. The reasoning is that you state the car will start and run,but only after "fuel" is introduced. Is not he fuel provided by a pressure signal from the oil sensor. The 10 second cranking alone would build enough oil pressure to close the ground to the fuel pmp relay. Once it is running, or has run ir will start shortly after but not after a long delay. Anyone see fault in this thought?

THE SHAGGYIROC
Old 05-24-2007, 10:11 PM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

Originally Posted by irocnroll89
HMMMM.Well, My stab at this would be the fuel pump relay/oil pressure sensor. The reasoning is that you state the car will start and run,but only after "fuel" is introduced. Is not he fuel provided by a pressure signal from the oil sensor. The 10 second cranking alone would build enough oil pressure to close the ground to the fuel pmp relay. Once it is running, or has run ir will start shortly after but not after a long delay. Anyone see fault in this thought?

THE SHAGGYIROC
Cranking the engine (providing oil pressure) will not ground the fuel pump relay...this is only accomplished by the ECM with a signal from the distributor (which occurs as soon as the engine turns). Also, the engine will build sufficient oil pressure to close the oil pressure switch within 5 seconds. Sounds like something is wrong with fuel delivery (even no fuel?) during crank.
Old 05-25-2007, 07:47 AM
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Re: L98 only starts w/ starting fluid, but runs fine, and starts fine after running..

What do your plugs look like? Also, if you have the means, ditch the cold start injector, cap the rail and runner port for it, and then run the 1989 F-body or vette code. I've fixed a couple of vettes and f-body's that had the same issue by doing the above.
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