Running problems with my 91

[rooftoplounge]

Hey all,

I've been trying to get my 91 running off and on for a few months. It runs nice when it's cold but after a couple of miles /10 minutes it just dies. The only way I can get it back home is by flipping the ignition and it'll surge, then cut out. I have to do that the rest of the way back home. I've replaced both fuel pumps, pump relay, air filter and cleaned the MAF.

I'm planning on checking the injectors next but will it run off the cold start injector until it warms up? It seems like it runs fine until it hits that point. I've picked up a fuel pressure gauge and will check it at the fuel rail over the weekend. Any suggestions?

[briano1234]

Two biggies that usually OK 3, 4 biggies that usually cause this are:

o2 sensor.
CTS sensor.
Fuel Pressure Regulator.
Vacuum leaks. replace all the cloth covered hoses with bulk from the parts store of your choice.
Check the Maf to Throttle body tube, I have one that developed a leak at the vent for the valve cover.

Unplug the o2 sensor and see if your car runs better... yes/no.
Yes, replace it. No, plug it back in and move on.

CTS sensor, when the car is running crappily unplug it.

These sensors (located on the front (grille) side of the head) cause all kinds of flaky crap, no start warm, cold, crappy idle.

Fuel pressure regulator. Do the tests in the Bentley they will nail one that is bad.

Why, over the summer, I had my green one where as soon as the car warmed up it wouldn't run.
It wouldn't even hot start.

Cold it would run till it warmed up a tad, then acted the ass.

o2 sensor was bad.


2 years ago I had a issue where the Green one (get driven hard), would start to throttle down after 20 minutes, I went through all kinds of crap but kept coming back to a possible fuel issue.

Took out my pressure gauge and did the tests outlined in the Bentley, and low and behold, that FPR was bad. It would bleed off pressure when it was warm. I was anal and measured the fuel flow in to the rail and out of the rail, and it stuck out like a sore thumb.

A few years ago, I got 500 knocked off the price of the Green Rabbit when I bought it as the owner never faced up to it not starting hot. Gee... I let it cool off, got it going, then drove it to the gas station and unplugged the CTS sensor.... Scrounged for the part, and replaced it....

So take care, and take measurements, and unplug stuff.

pssst 91's don't have cold start injectors, they have ISV's.