Good spark, fuel pressure and injector yet terrible starting

Tom and Ray did not bite on this question, probably because they never cared for Geo Metros. This one has 203,000 miles and was perfect until recently. Then the water pump failed and because of the overheating the headgasket blew. After the repair (including a new distributor O-ring), it ran well for 2000 miles though had high oil consumption (1qt/500 mi). But now I have to crank it forever to get it started. It putt-putts for a minute or more with the starter engaged, then runs normally. I took it to a Cartalk-recommended shop (Mike Vinson’s in Scottsdale), and they could find nothing. They said it had good compression (how can that be if it burns oil?), that the injector timing is good, fuel pressure fine, and spark good. Their last word before they gave it back to me was: “It’s got to be something in the cylinder head, but we don’t know what”. Again: after a very extended crank, it runs perfectly, with perhaps slightly reduced power and burning oil. Starts right up shortly after turning off, but cranks forever before starting after an hour or more of sitting. No improvrement if I turns off the ignition at higher rpm, to load the cylinders with fuel. Scan shows “cylinder 2 misfire”, but all sparkplugs look clean and hot.

The shop said fuel pressure was good, but did they see how long it took fuel presssure to drop after engine is turned off? One leaking o-ring could cause long crank time, but wow, one minute! I guess this is a shot in the dark but run this by shop anyway.

There could be a problem with the pulsator valve in the fuel pump assembly. The pulsator valve prevents the fuel from draining back into the tank from the fuel rail/supply line. When this happens, it takes the fuel pump a longer time to refill the fuel line/fuel rail and to restore the fuel pressure at the injectors.

To find out if this is what’s happening, the next time you know this long start time is going to happen, just turn the ignition switch to the run position for a second or two and then turn the ignition to the off position. Repeat this a half dozen times or so and then try starting the engine. If the engine starts right up, the pulsator valve in the fuel pump assembly is defective.


if it burns oil, you should get new rings installed anyways, if you can do it yourself, take a look while your in there, it sounds to me like they only tested compression on one cylinder.

Tester, leaving the ignition on for a minute before cranking does the trick. Can I install a checkvalve (what kind?) in the fuel line, such that I do not have to replace the fuel pump which, as I understand, requires removal of the tank? Or an auxiliary fuel pump in the fuel line?

The only way to fix this is to replace the fuel pump assembly. But hey! Now that you know what the problem is, just cycle the ignition switch to get the engine started. The fuel pump can run a long time with a bad pulsator valve. Then when the fuel pump itself starts showing problems, then replace it.


TJ, Vinson lied to me. I checked the compression, and it’s 120/115/105 in cylinders 1/2/3 instead of the minimum specified, 157. They did not check it. But new rings alone won’t do it, I think. Don’t the cylinders have to be honed?

Yes Karl, you had the right general idea. See my answer to Tester. The shop is incompetent

With compression that lousy it’s a miracle it runs at all. Overheating has barbecued the rings and quite possibly scored the cylinder walls. Honing and new rings are not feasible on a car that has been seriously overheated and has over 200k miles on it.

It will require cylinder boring and this means a complete engine overhaul. There’s no way around it.
I always hate to hear that “has good compression” crap on this board because in 98% of the cases the compression readings are junk.
The shop is dead wrong by saying those figures are good. It is NOT the shop’s fault the rings are roasted; that is all on you.
The shop SHOULD make you aware of a potential oil buring problem whenever a head gasket is required due to extended overheating.
(FYI. Even if all cylinders had the 157 PSI you mention the engine can still burn oil like crazy.)