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98 s70 fuel injector ohms - no start?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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marcusheard
Posts: 71
Joined: 26 July 2012
Year and Model: S70 turbo, 1998
Location: TX

98 s70 fuel injector ohms - no start?

Post by marcusheard »

I have a 98 s70 2.4L Turbo GLT:

Reading 17.2 ohms all injectors (I read that they should be between 12.8-14.5 ohms - I'm not positive)
Reading 15,000 ohms secondary resistance at ignition coil ( I read that it should be between 8000 - 9000 ohms - I'm not positive)

Will the fact that they are both high cause a no start?

Thanks,

jimmy57
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Post by jimmy57 »

Those specs are at 20C/68F and are for wire windings of wire that is human hair thin, if not thinner. The wire gains resistance with temp an unless you have your car in air conditioned garage those would be expected readings.
Do you have no spark and no injector pulses?

jimmy57
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Year and Model: 2004 V70R GT, et al
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Post by jimmy57 »

When it fails to start have you checked any one of the green wires at injectors to see if there is 12V?

marcusheard
Posts: 71
Joined: 26 July 2012
Year and Model: S70 turbo, 1998
Location: TX

Post by marcusheard »

OK, the wires are at 30°C. I haven't purchased a noid light just yet, I plan to buy a cheap one from Harbor Freight Tools the next time that I'm there.
Last edited by marcusheard on 07 Aug 2012, 20:59, edited 1 time in total.

jimmy57
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Post by jimmy57 »

The 6.34 V is while cranking engine over?

marcusheard
Posts: 71
Joined: 26 July 2012
Year and Model: S70 turbo, 1998
Location: TX

Post by marcusheard »

No, just in the II position after unpluging the injector and probing the plug with my multi meter

jimmy57
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Post by jimmy57 »

You don't have to have a noid light to check injector pulses. You backprobe by straightening one end of paper clip and sticking it through the rubber seal until you feel it contact the terminal. DO it for both injector wires. Probe with voltmeter on both those probes. You will have 0-0.030 V and when cranking over your meter should change number, go up. If there is a ground pulse to turn on injector the voltmeter would have 12 +/- V for the 3-4 milliseconds of injector squirt time. The voltmeter can't change display that fast but it should jump up to 2, 3 ,4 volts to show there was that brief ground pulse.

marcusheard
Posts: 71
Joined: 26 July 2012
Year and Model: S70 turbo, 1998
Location: TX

Post by marcusheard »

Thanks Jimmy57 for all of the time spent helping me attempt to locate my problem - I really appreciate the help - Jimmy57 is hinting towards me having a bad wire somewhere

OK, here is my conclusion - see attached form:
Voltage conclusion.docx
(14.76 KiB) Downloaded 303 times
Keep in mind that all of this data was captured without turning the engine over since the engine does not start without jumping the main relay

So this leads me to wonder - before the engine is cranked or turned over - what will inhibit my main relay from crossing 12V to pin 3 to provide current to the green wires of my fuel injectors, turbo control valve, idle control valve, MAF, fuses 2, 3, 4, and 5 in the engine bay, and my ignition control module (also referred to as ignition coil and amplifier)?

I'm convinced that my green wires are good - mostly because after jumping my main relay I see voltage on the green wires that is fairly constant across the system at approximately 10.4V

I'm not sure, but it seems like my engine control computer is unhappy with some data that it receives after turning the key to the II position - or is it an engine control problem?

I have replaced: cam position sensor (300 ohms at 30°C), crankshaft position senor, distributor cap, ignition control module (15,000 ohms at 30°C), spark plugs and coolant temperature sensor.

Tomorrow I will replace the spark plug wires and install a volvo brand ignition control module rather than the current after market type that is on there now (I'm hoping that the vovlo brand will have less than 15,000 ohms at 30°C - I would like to see 8,000 - 9,000 ohms at 30°C)

My current fuel injectors are at 17.2 ohms at 30°C - I would like at set that is between 12.8 - 14.5 ohms at 30°C - to see if that makes my engine control computer a lot happier

I sure hope that there is a simple solution to this starting problem

Thanks,

marcusheard
Posts: 71
Joined: 26 July 2012
Year and Model: S70 turbo, 1998
Location: TX

Post by marcusheard »

I finally located my bad connection as Jimmy57 suggested, its in the front driver side corner near the battery. It looks decent but if I slightly move this connector (24/43 in diagram), then the engine stumbles and stalls. I believe that this connector grounds my main relay though my ECU. So my question: could this be shorting lets say: my main relay, fuel relay, or ICM? Because I can't seem to wiggle this connector back into an acceptable postion to get my car to restart, but if I install a new ICM the fuel pump will prime, and everything else works perfectly and the car starts fine and idles smoothly. I'm wondering how do I fix this problem, any ideas people?
bad plug.jpg
bad plug.jpg (442.36 KiB) Viewed 2624 times
Engine connectors.jpg
Engine connectors.jpg (373.3 KiB) Viewed 2626 times
Fuel system wiring.jpg
Fuel system wiring.jpg (538.22 KiB) Viewed 2626 times

marcusheard
Posts: 71
Joined: 26 July 2012
Year and Model: S70 turbo, 1998
Location: TX

Post by marcusheard »

Solution: spliced wire with bad connector (I could not get continuity on both sides of the connector for this wire) pin and bridged the two ends. Took it for a short test drive and so far so good.
spliced wire.jpg
spliced wire.jpg (619.22 KiB) Viewed 2616 times

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