94 Hard Starts, Runs Good ???

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94 Hard Starts, Runs Good ???

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Corvette >> Corvette Models >> Corvette C4 Forum >> 94 Hard Starts, Runs Good ???

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94 Hard Starts, Runs Good ??? - 4/19/2008 10:28:42 PM

OzoneTrash

Posts: 25
Joined: 2/17/2007
Status: offline

I’m stuck with this one. I have read the other threads on the same subject but my problem is a little different.
Car cranks for a while before it starts (about 15 – 20 seconds). Once it starts both cooling fans come on about 3 seconds after the engine starts. No codes but service engine light is on. I can hook up my scanner and hit clear codes the light will go off and fans will stop for a couple of seconds then they both come back on. I have done about everything the FSM says.
Here’s a list of what I have done so far to remedy this problem. What am I missing ?

Parts Replaced:
Granatelli MAF, Injectors, ICM, MAP, Coolant Sensor in Water Pump, Fan Relays, Fuel Pressure Regulator

Stuff that I Checked :
Fuel Pump Pressure is 41psi with vacuum off FPR. Is 41psi good enough? But that still don’t solve the fan problem, Removed and Cleaned IAC Pintle, The FSM says for the fans running possibly a faulty ECM, I have installed 3 different bins and nothing.

Any help will be appreciated.

Thanks,
Steve

Post #: 1

RE: 94 Hard Starts, Runs Good ??? - 4/19/2008 11:59:23 PM

cwb

Posts: 1407
Joined: 5/13/2007
From: eastern NC
Status: offline

quote:

ORIGINAL: OzoneTrash
Car cranks for a while before it starts (about 15 – 20 seconds).

Cold motor?

Or hot motor?

Or both... ?

_____________________________

Today's my birthday!

Plain ole' '94. Clean. And tight.

My vette; NOT my favorite wax.

(in reply to OzoneTrash)

Post #: 2

RE: 94 Hard Starts, Runs Good ??? - 4/20/2008 3:20:00 PM

LeesVette

Posts: 542
Joined: 3/24/2006
Status: offline

That sounds like an ECM problem to me. I am by no means, as many will attest, an expert.

(in reply to cwb)

Post #: 3

RE: 94 Hard Starts, Runs Good ??? - 4/20/2008 4:31:52 PM

OzoneTrash

Posts: 25
Joined: 2/17/2007
Status: offline

It does it cold or hot. I'm starting to thing ECM myself. I thought I had a ECM won on ebay but I was wrong, it sold. I was told to check the temp with my scanner to see if the ECM thinks the engine is hot, if so it will cause this problem also. I'll update with that info.

Thanks,
Steve

(in reply to LeesVette)

Post #: 4

RE: 94 Hard Starts, Runs Good ??? - 4/20/2008 4:51:27 PM

mech259

Posts: 1720
Joined: 1/22/2006
From: Lumberton, Texas
Status: offline

Have you checked to see if it is spark or injector pulse? Both are related to Opti distributor cam sensor. Do you have a noid light to check injector pulse and a spark checker for spark?

_____________________________

L.B.
ASE Master Certified
L1 Emissions Certified
1986 C4
1969 RS Z28 Camaro
1970 Chevelle SS 396 (under construction)

(in reply to OzoneTrash)

Post #: 5

RE: 94 Hard Starts, Runs Good ??? - 4/20/2008 6:24:31 PM

OzoneTrash

Posts: 25
Joined: 2/17/2007
Status: offline

quote:

ORIGINAL: mech259

Have you checked to see if it is spark or injector pulse? Both are related to Opti distributor cam sensor. Do you have a noid light to check injector pulse and a spark checker for spark?

I dont have a noid checker. I did just change the opti-spark with a new GM with a new MSD vacuum vented cap. I also change to a new MSD coil. Changed all the plugs and wires at that time also.

< Message edited by OzoneTrash -- 4/20/2008 6:44:17 PM >

(in reply to mech259)

Post #: 6

RE: 94 Hard Starts, Runs Good ??? - 4/21/2008 4:29:49 PM

mech259

Posts: 1720
Joined: 1/22/2006
From: Lumberton, Texas
Status: offline

Still need to check for spark and injector pulse. Also, is the 41lbs of fuel pressure instant when key is turned on?

_____________________________

L.B.
ASE Master Certified
L1 Emissions Certified
1986 C4
1969 RS Z28 Camaro
1970 Chevelle SS 396 (under construction)

(in reply to OzoneTrash)

Post #: 7

RE: 94 Hard Starts, Runs Good ??? - 4/26/2008 3:36:24 PM

OzoneTrash

Posts: 25
Joined: 2/17/2007
Status: offline

quote:

ORIGINAL: mech259

Still need to check for spark and injector pulse. Also, is the 41lbs of fuel pressure instant when key is turned on?

My noid light came in today. I have injector pulse while cranking but no spark. After about 20 seconds give or take I get spark and it starts. After seeing I have no spark I didn't recheck the fuel pressure. What is giving me the delay in spark. I have new Opti, new coil, new ICM, new MAF. I cant think what else I have replaced.

Thanks,
Steve

< Message edited by OzoneTrash -- 4/26/2008 3:56:54 PM >

(in reply to mech259)

Post #: 8

RE: 94 Hard Starts, Runs Good ??? - 4/26/2008 6:43:07 PM

mech259

Posts: 1720
Joined: 1/22/2006
From: Lumberton, Texas
Status: offline

If you have injector pulse and no spark, chances are you do not have dist. probs. Have you checked your 12v supply to the coil?

_____________________________

L.B.
ASE Master Certified
L1 Emissions Certified
1986 C4
1969 RS Z28 Camaro
1970 Chevelle SS 396 (under construction)

(in reply to OzoneTrash)

Post #: 9

RE: 94 Hard Starts, Runs Good ??? - 4/27/2008 3:18:23 PM

OzoneTrash

Posts: 25
Joined: 2/17/2007
Status: offline

I have 12v to the grey connector red wire with black strip, no voltage on the white wire. No voltage to both wires on black connector. This reading is with the ignition on.

I just went to take it for a ride and now when I give it throttle it stalls really bad. This is new, its never done this before. At higher RPM's is seemed to run alright.

< Message edited by OzoneTrash -- 4/27/2008 4:00:11 PM >

(in reply to mech259)

Post #: 10