No Start!!
Thread Starter
Racer
Joined: Jul 2006
Posts: 377
Likes: 1
From: Frisco, TX
No Start!!
Hi Everybody,
Need some help figuring this one out. On my 87 auto I am having a odd no start problem. I disconnected and cleaned the MAF today with CRC maf cleaner, after putting it back together the car started right up but idled high (1K). I shut off the car and attempted to restart, and nothing, the car turns but no start?
I disconnected the battery and reconnected 2 minutes later and the car starts? I then shut it off and try to restart and again no start, until I disconnect the battery?! I checked and switched relays and that did not change anything. Any idea's, advice?
Thanks,
Danny
Need some help figuring this one out. On my 87 auto I am having a odd no start problem. I disconnected and cleaned the MAF today with CRC maf cleaner, after putting it back together the car started right up but idled high (1K). I shut off the car and attempted to restart, and nothing, the car turns but no start?
I disconnected the battery and reconnected 2 minutes later and the car starts? I then shut it off and try to restart and again no start, until I disconnect the battery?! I checked and switched relays and that did not change anything. Any idea's, advice?
Thanks,
Danny
Burning Brakes
Joined: Oct 2008
Posts: 972
Likes: 0
From: Palo Alto, CA
If you get the car to start, then turn it off as before, wait two minutes without disconnecting anything and see if it starts. My guess is that it could be overheating starter motor, and battery/high idle is unrelated gremlin. If the successful restart requires disconnecting the battery, then maybe they are related. I'd guess its more of a time issue than a battery issue though
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Joined: Oct 2001
Posts: 20,506
Likes: 564
From: Bend, Oregon
Danny--
Remove the MAF again, and inspect the boot between the MAF and the throttle. There are oil vapor hoses that connect there, and those hoses and connectors may have been dislodged slightly the first time around. Old, tired and crispy means they are more easily damaged. Look carefully at the end of the boot where the MAF fits, for tears or other damage that might allow air to leak in. If everything looks good, install the MAF again. Snug but not too tight on the clamp that holds it in the boot.
Two things point to false air coming in after the MAF. The high idle actually suggests a leak downstream of the throttle, and that might be as easy as a vacuum hose dislodged fro the throttle, or maybe damaged. Could be collateral damage at the FPR or dampers. The starts-once syndrome suggests an air leak too, but it could be upstream or downstream of the throttle. When the engine is cold or first-started, there's a little extra enrichment of the mixture that would allow starting with the air leak. Once it warms a bit, no more cold enrichment and it's struggling. Not enough air passing through the MAF when cranking to get fuel flowing.
Inspect the electrical harness and particularly the wiring condition through the boot.
That's my nickel diagnosis. More than my normal two sense worth, but not by a lot.
Remove the MAF again, and inspect the boot between the MAF and the throttle. There are oil vapor hoses that connect there, and those hoses and connectors may have been dislodged slightly the first time around. Old, tired and crispy means they are more easily damaged. Look carefully at the end of the boot where the MAF fits, for tears or other damage that might allow air to leak in. If everything looks good, install the MAF again. Snug but not too tight on the clamp that holds it in the boot.
Two things point to false air coming in after the MAF. The high idle actually suggests a leak downstream of the throttle, and that might be as easy as a vacuum hose dislodged fro the throttle, or maybe damaged. Could be collateral damage at the FPR or dampers. The starts-once syndrome suggests an air leak too, but it could be upstream or downstream of the throttle. When the engine is cold or first-started, there's a little extra enrichment of the mixture that would allow starting with the air leak. Once it warms a bit, no more cold enrichment and it's struggling. Not enough air passing through the MAF when cranking to get fuel flowing.
Inspect the electrical harness and particularly the wiring condition through the boot.
That's my nickel diagnosis. More than my normal two sense worth, but not by a lot.
Trending Topics
Rennlist Member
Joined: Mar 2002
Posts: 6,115
Likes: 344
From: Texas
Danny,
Check that your grounds at the back of the engine on either side of the "V" are clean and tight. It could be that your injectors are not finding a ground and are therefore not injecting.
Check that your grounds at the back of the engine on either side of the "V" are clean and tight. It could be that your injectors are not finding a ground and are therefore not injecting.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
10 Reasons I Hate Going to the Porsche Dealership (& the 1 Reason I Stay)
Joe Kucinski
Porsche Shakes Up The Nürburgring Lap Record Table Once Again
Verdad Gallardo
6 Ways the Porsche 911 GT3 S/C Redefines Performance
Joe Kucinski
10 Wildest Homologation Specials Porsche Ever Sold
Verdad Gallardo
Super Rare RUF BTR III Comes Out of Hibernation, Looking For a New Home
Verdad Gallardo
10 Porsche Opinions That Can Start a Fight
Joe Kucinski
Team Owner
Joined: May 2004
Posts: 31,187
Likes: 4,177
From: Philly PA
has the CPS been replaced?
we really need more info about what you have done?
what were the last few things you fixed?
Have the computers been rebuilt? If the MAF is original now is a good time to have it checked or rebuilt or refreshed
we really need more info about what you have done?
what were the last few things you fixed?
Have the computers been rebuilt? If the MAF is original now is a good time to have it checked or rebuilt or refreshed
Thread Starter
Racer
Joined: Jul 2006
Posts: 377
Likes: 1
From: Frisco, TX
Merlin-
I have not replaced the cam position sensor, nor the brains or Maf. I have recently(4 months ago) completed an intake redo, I replace the ISV, TPS, gaskets, oil breather hoses, Vacuum lines, elbows, tees.
John, When I did the intake, I cleaned every ground point on the car.
The biggest change on the car right now is that is also shutting off, like an off switch??
Thanks-
Danny
I have not replaced the cam position sensor, nor the brains or Maf. I have recently(4 months ago) completed an intake redo, I replace the ISV, TPS, gaskets, oil breather hoses, Vacuum lines, elbows, tees.
John, When I did the intake, I cleaned every ground point on the car.
The biggest change on the car right now is that is also shutting off, like an off switch??
Thanks-
Danny
Rennlist Member
Joined: Mar 2002
Posts: 6,115
Likes: 344
From: Texas
Danny, do you have a fuel pressure gauge mounted on your fuel rail? If so, do you have fuel pressure?
The reason I asked about the grounds is that my blue '89 would just shut down for no known to me reason. I found out that it had no engine ground(at least not a full time functioning one) When it found a ground, it ran great, when it lost that ground, it stopped cold and dead. The braided engine ground on the passenger side under the car was there and looked functional, but was not making a connection. I tested it, cleaned it, and reinstalled it, and tightened up the grounds at the back of the 'V" and it has run ever since.YMMV
The reason I asked about the grounds is that my blue '89 would just shut down for no known to me reason. I found out that it had no engine ground(at least not a full time functioning one) When it found a ground, it ran great, when it lost that ground, it stopped cold and dead. The braided engine ground on the passenger side under the car was there and looked functional, but was not making a connection. I tested it, cleaned it, and reinstalled it, and tightened up the grounds at the back of the 'V" and it has run ever since.YMMV
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Joined: Oct 2001
Posts: 20,506
Likes: 564
From: Bend, Oregon
Danny--
If you haven't rebuilt the LH box yet, might be something to try in another car just to get it off the list of possibilities. Some fail glamorously, with lots of injector ticking and clicking. Mine failed a slow and tedious death, with some of the symptoms you describe. Any S4+ can be used to demo your controller.
If you haven't rebuilt the LH box yet, might be something to try in another car just to get it off the list of possibilities. Some fail glamorously, with lots of injector ticking and clicking. Mine failed a slow and tedious death, with some of the symptoms you describe. Any S4+ can be used to demo your controller.
