cranks but no start – interesting problem solved - ZR-1 Net Registry Forums

ghlkal · 10-05-2014

I’ve fixed the problem, but maybe the procedure and solution to the problem can help someone else.

I pulled the Z out to wash it on Friday in anticipation of a car show on Saturday. When finished, I fired her up to pull her back into the garage, put it in reverse and the engine died. I tried to restart, but it just cranked and wouldn’t run.

OK, so I crack open the FSM to section 6E and follow chart A-3. I put the “ECM plus” cartridge into my Tech 1 and plugged it in.

- ignition on, SES light is lit (good thing)
- no codes are currently set (good thing)
- actual coolant temperature is indicated on scan tool (yes)
- TPS is at .54 volts (good thing)
- engine RPM indicated during cranking (showed 150 RPM, good thing)
- using my in-line tester, there is spark at plugs 1, 3, 5, and 7 (good thing); be sure to pull only one wire at a time and test
- using my test light, there is injector pulse at primary injector 2 connector (good thing)
- using my gauge, there was no fuel pressure on the rail (bad thing)
- I checked the fuses for FP1 and FP2 are both were good
- I applied 12 volts to fuel pump test terminal and I can hear the fuel pump(s) run
- I turned the key to on and I can hear the fuel pump(s) run

So … this points to a plugged fuel filter, or fuel line, or inlet filter, or disconnected hose according to the FSM

Just a few months ago I had the fuel filter replaced and installed a new sending unit and fuel pumps. I asked Marc Haibeck and he suggested that to check for a loose hose in the tank look in the tank with the pumps running. If you see “waves” then the pump is pumping into the tank and not through the line.

Well, I looked and I saw waves in the tank. When I pulled the sending unit out, I discovered that a hose had come off one of the pumps. This was a new one to me. I’ve put 2000 miles on the car since replacing the sending units and pumps. I’m thankful this happened in my driveway and not 500 miles from home!

Anyway there’s nothing new here for the experts, but maybe it will help other newbies like me. Here’s what I learned – I like driving my Z better than working on it

Gary

PhillipsLT5 · 10-05-2014

Marc is da man

Vette Guy · 10-06-2014

This happened to me, as well as another ZR-1er.... the new fuel pumps do not have a retaining flange for the hose. It slides off over time if you use the plastic hose clamps - others have been successful using small metal ones.

Regards,
Mark

We Gone · 10-06-2014

Good job, I've seen this happen many times on older C4's, over time the rubber lines swell and get lose or the plastic clamp will deteriorate. I use SS clamps if I ever have to work on the pump in the tank.

ghlkal · 10-06-2014

Good points about the new pumps and the connector ...

SS hose clamps were used ... I guess they just weren't clamped down tight enough.

10-05-2014	#1
ghlkal Join Date: Jan 2012 Location: Wisconsin Posts: 887	cranks but no start – interesting problem solved I’ve fixed the problem, but maybe the procedure and solution to the problem can help someone else. I pulled the Z out to wash it on Friday in anticipation of a car show on Saturday. When finished, I fired her up to pull her back into the garage, put it in reverse and the engine died. I tried to restart, but it just cranked and wouldn’t run. OK, so I crack open the FSM to section 6E and follow chart A-3. I put the “ECM plus” cartridge into my Tech 1 and plugged it in. - ignition on, SES light is lit (good thing) - no codes are currently set (good thing) - actual coolant temperature is indicated on scan tool (yes) - TPS is at .54 volts (good thing) - engine RPM indicated during cranking (showed 150 RPM, good thing) - using my in-line tester, there is spark at plugs 1, 3, 5, and 7 (good thing); be sure to pull only one wire at a time and test - using my test light, there is injector pulse at primary injector 2 connector (good thing) - using my gauge, there was no fuel pressure on the rail (bad thing) - I checked the fuses for FP1 and FP2 are both were good - I applied 12 volts to fuel pump test terminal and I can hear the fuel pump(s) run - I turned the key to on and I can hear the fuel pump(s) run So … this points to a plugged fuel filter, or fuel line, or inlet filter, or disconnected hose according to the FSM Just a few months ago I had the fuel filter replaced and installed a new sending unit and fuel pumps. I asked Marc Haibeck and he suggested that to check for a loose hose in the tank look in the tank with the pumps running. If you see “waves” then the pump is pumping into the tank and not through the line. Well, I looked and I saw waves in the tank. When I pulled the sending unit out, I discovered that a hose had come off one of the pumps. This was a new one to me. I’ve put 2000 miles on the car since replacing the sending units and pumps. I’m thankful this happened in my driveway and not 500 miles from home! Anyway there’s nothing new here for the experts, but maybe it will help other newbies like me. Here’s what I learned – I like driving my Z better than working on it Gary __________________ 1990 ZR-1 #2180 Red/Black Many of the usual mods for 460HP, tuned by Marc Haibeck ZR-1 Net Registry Member #1548

10-05-2014	#2
PhillipsLT5 Join Date: Aug 2005 Location: Scottsdale, AZ Posts: 2,452	Re: cranks but no start – interesting problem solved Marc is da man

10-06-2014	#4
We Gone Join Date: Apr 2004 Location: ATL. GA. Posts: 2,170	Re: cranks but no start – interesting problem solved Good job, I've seen this happen many times on older C4's, over time the rubber lines swell and get lose or the plastic clamp will deteriorate. I use SS clamps if I ever have to work on the pump in the tank. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

10-06-2014	#5
ghlkal Join Date: Jan 2012 Location: Wisconsin Posts: 887	Re: cranks but no start – interesting problem solved Good points about the new pumps and the connector ... SS hose clamps were used ... I guess they just weren't clamped down tight enough. __________________ 1990 ZR-1 #2180 Red/Black Many of the usual mods for 460HP, tuned by Marc Haibeck ZR-1 Net Registry Member #1548