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Cold Start Sputter - No Boost

2K views 11 replies 6 participants last post by  Mag-X 
#1 ·
I did a search, but using the words "cold start" brings up almost every thread in the C900 section. I couldn't find one with my exact problem(s).

Starting the motor from a cold start results in one of two scenarios.

Scenario A)
1) Turn the key once: cranks and cranks, but doesn't fire.
2) Turn the key a second time, and it cranks and sputters and shakes, but doesn't actually start
3) Turn three it fires right up, but I cannot touch the gas pedal for a few minutes, or it will stall.
4) Starts running fine, but no boost

Scenario B)
1) Starts up first try, works great, but check engine light comes on.
2) No boost!

Then about 20 minutes later the boost just comes back.
 
#3 ·
Mag-X said:
I did a search, but using the words "cold start" brings up almost every thread in the C900 section. I couldn't find one with my exact problem(s).

Starting the motor from a cold start results in one of two scenarios.

Scenario A)
1) Turn the key once: cranks and cranks, but doesn't fire.
2) Turn the key a second time, and it cranks and sputters and shakes, but doesn't actually start
3) Turn three it fires right up, but I cannot touch the gas pedal for a few minutes, or it will stall.
4) Starts running fine, but no boost

Scenario B)
1) Starts up first try, works great, but check engine light comes on.
2) No boost!

Then about 20 minutes later the boost just comes back.

Is this on an 8V or a 16V car? I've found that on my 8V cars, esp. the older few with the fully-pressurised tank and no pre-pump, the engine(s) start but revs drop right down for a few seconds after letting go of the key, then come back up to normal, and I've determined that's just because of the fuel pressure still coming up as the pump pressurises the tank and starts to push fuel through the lines to the fuel distributor.

In 16V cars I wouldn't expect this sort of thing to happen, or in the 85+ 8V cars, since they all have the double-pump setup, however my theory could be off-track for your problem.

When I first got my 81 turbo car (8V non-apc) it had the wrong fuel pump relay. Instead of the special version with the extra terminal-50 connection, it had the version used in the non-turbo cars. I changed that for the right version (salvaged from the 83 turbo that I'm stripping [took more stuff off it yesterday!]), but it didn't seem to make a lot of difference.

Craig.
 
#8 · (Edited)
I've heard a simple check of the AMM is to pull it off the filter, and have someone put the key in the run position... then look inside the AMM to see the small wire heating up and glowing orange...did the check on my 92 once and sure enough it glowed.

edit - I believe it only lights up for a sec and then goes out, so if you do the check look closely.
 
#10 ·
You haven't been spray/steam cleaning the engine by any chance in the past day or so, or gone through big puddles? Had all these symptoms after cleaning the engine.. split or degraded rubber boots (on the back of the various electrical plugs) can do it, as can water in or around the top of the AMM.. just a thought....
 
#12 ·
silversaab96 said:
You haven't been spray/steam cleaning the engine by any chance in the past day or so, or gone through big puddles? Had all these symptoms after cleaning the engine.. split or degraded rubber boots (on the back of the various electrical plugs) can do it, as can water in or around the top of the AMM.. just a thought....
No. There hasn't been a heavy rain in weeks.
 
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