Hi,

just bought a '89 Grand Prix over here in germany, car is in excellent condition except for some minor problems, hope you guys can help me.

The cruise control ain't working, pressure hoses are fine, the switch at the brake pedal seems to be fine, the cruise control lever seems to be fine, all cables connected.....is there some kind of cruise control module that may be broken ? What else can I check ?

Car is very hard to start in the morning, or when it hasn't been driven for some hours and the engine is cold. Starts within a sec when the engine is warm. So I guess the problem is not fuel or ignition related.
Fuel pump is working, Alternator new, battery new, spark plugs new, fuel filter new, starter working. It takes 5-10 tries to get it started when cold. Leaky intake manifold gaskets maybe ? What do you think ?
Are there any known spots that are likely to leak ? Could be it be the IAC or MAF or crank shaft sensor ? But I guess then it would happen all the time or am I wrong ? No SES light by the way.

Hope you guys can help, I'm afraid of ruining the starter and battery if I don't find the prob soon.

Thanks.

Chances are you problem is a bad fuel pressure regulator. It sounds like it is not holding proper pressure and you are having to build pressure each time you start the vehicle. It could also be the injectors themselves. I had a 2.8 that was very hard to start. The injectors were replaced and the problem went away. Expensive fix though. As for your cruise control, I have no idea other than what I call the vacuum can. It is the round thing that controls the cruise. If they go bad the cruise will not work.

Thanks for your reply.

How can I check if it's the fuel pressure regulator ? At this valve on the fuel rail ? What should the gauge read then ? Wouldn't the pressure then also be too low when starting the engine when it's hot ?

I forgot to mention that the coolant fan is running all the time, do you think this has anything to do with the problems ? I ordered a new coolant temp sensor as the guys in the shop told me there's no seperate fan switch as on 350 TPI Engines, and this coolant temp sensor also controls the fan. Is it possible that this sensor is connected to the ECM, and the ECM doesn't know I'm doing a cold start and maybe then too less fuel is injected ?

It is a good possibility that the ecm is not reading a cold start. Change the temp sensor and see if that helps. The fuel pressure varies but for your particular car it shouldn't be less than 40.5 psi nor more than 47psi with the pump running. You can check it with a fuel pressure guage at the rail. It is possible that the pressure would be too low when hot but a hot engine starts easier and requires less fuel. I would go with you temp. theory first then check the fuel system.

Still have the cold start problems, dunno what else to look for....

Swapped the coolant temp. sensor, swapped the whole injection incl. fuel rail, pressure regulator, injectors, swapped the ignition coils, swapped the spark plugs and wires.

Also still have that weird fan behavior, fan turns on at about 140, turns off, turns on at 180, doesn't stop running then.

Couldn't check the fuel pressure, still waiting for a pressure gauge I ordered.

What is left to check ? Fuel pump ? IAC ? Crankshaft position sensor ?
ECM ?

Do you know if I can use the ECM of a '89 Beretta with the same engine ? The serial number of the ECM is different. And it has no MAF like the Grand Prix I think. Don't wanna spend money for nothing and it's quite difficult to find used parts here in Germany.

If you guys got any more ideas for me, please help....

Thanks.

I doubt the ecm from an 89 Beretta will work even though it has the same engine. You could always try it though if it works then so much the better. Should be a simple plug in. The CPS on the 2.8 is not too hard to change and only costs about $45. If the car runs right once it is started then the fuel pump should be good. The only other thing I can think of is the tps, it may not be communicating with the ecm to tell it that the car is in the cold start mode. This is about everything I can think of since you covered everything else. Good Luck!