my 88 90Q has always had a bit of a goofy startup - it fires ones, then immediately dies, then fires again and limps up to idle speed.

i have the symptom of not being able to re-fire the car after letting it sit for a while. this has left me unable to drive 3 times now. it happened for the 2nd time yesterday so i just left it parked infront of the house.

today i went out to get it, figuring its sat over night so it will be fine. it started really hard but i got it running. then i pulled around into the alley to load some stuff and it died when i let off the gas, never to re fire.

in a fit of frustration i started pulling stuff apart to test

1) im getting spark no problem
2) cold start valve is getting fuel during 2-sec pump priming
3) the main injectors DO NOT SPRAY during the 2-sec pump priming. However, if i manually lift the CIS plate so its like an inch up in the air, then they all shoot fine, and all roughly the same amount. Additionally, they dont leak after the 2 sec cut off.

4) There are some holes/tears in the plastic mega-elbow between CIS unit and TB

5) there are all kinds of un-clamped vacuum lines. I fixed some of them, but ran out of hose clamps

Anyway, after i forced gas through all the injectors by pump priming with the CIS unit maxxed open, i put the car back together and it eventually fired and wnated to die a bit, but i kept it running at 4k rpm for about 30s.. then i slowly let it come down to idle. it idled fine for like 10 minutes and then i drove it around the block. no dying or anything.

So i guess what i've heard is that hot start problems are from a loss of fuel pressure which lets the hot fuel form bubbles and then the mechanical injectors cant open. My plugs were way way dry when i checked them. Normally this is caused by the check valve leaking pressure or the injectors leaking pressure. I didn't see obvious evidence of the injectors leaking, so does that mean i should definitely replace the check valve?

Any other thoughts?

BTW, my check valve, pump, pump tray, and filter are all basically rusted together :P

 

"4) There are some holes/tears in the plastic mega-elbow between CIS unit and TB" - this is a major issue.

Get some PB Blaster and go at your whole pump tray unit. Replace the check valves and also if things are that rusty you should probably replace nitrogen filled pressure accumulator. aaand while you've got it apart change the fuel filter.

 

<img src="http://home.wi.rr.com/infernocl/car%20stuff/hose%20that%20breaks.JPG">

if that is ok then check ISV, clean it and check the connection under the plug boot. My plug is fvcked and need a new one, car would barely idle or die when i hit the gas.

 

I took all that apart yesterday, none if it had hose clamps, now all of it does. No real difference.

I blew compressed air through everything also. Is there some better way of cleaning the ISV ?

 

carb cleaner, also check the connector under the boot