1988 740 Turbo

I've posted on here before, but I've very little progress since, so I was hoping to get some new perspective on this..

Here's a brief history of what's going on:

-Used engine swap due to engine blow out
-Car ran strong before, including turbo
-When I got the car back, I was having hot start problems
-Once the car would get so hot, it would die
-Diagnosed and replaced fuel pump relay; radio suppression relay was ok

So here's where I start to get stumped. I swapped out the fuel pump relay, but the car was dead, so I got a jump and it fired right up. Since I've started to have the hot start problems, once I revved the car up to about 3500 RPM, it would "stutter." I kept doing that in neutral and eventually the car died again, needing a jump. The relay also started buzzing once it died. I was told the most common cause for a buzzing relay was a corroded positive bettery cable, but that doesn't account for the stuttering at 3500 RPM. Is my turbo going bad? I've never dealt with a turbo vehicle before, so could a malfuctioning turbo be draining the battery, thus causing it to die?

I'm starting a new job soon where I have to commute, so any help is much appreciated.

If you replaced the engine because it "blew", it's quite possible you cooked some wires due to overheating, so I suspect your problem is electrical.

Check the wires and the battery. If it won't start when warm it's a sign the cables, connections or the battery are fried fried. Just clean teh battery connections first then put all lights on and check whether they dim (turn yellow) or not. If they dim, the problenm is the battery (no charge). Check battery fluids and recharge as necessary then check again. Fully cahrged it shoudl start teh car no problem at all. Heck if you don't know, simply replace the battery and try again.

Thn check the alternator wire, it's quite susceptible to frying in this car, and will cause teh abttery to failin short order.

Lack of electricity will make the ligts dim, the relays buzz and the coil put out insufficient spark under high demand.

HTH...

if the car is not charging and you always need a jump, the stuttering could be a voltage problem. not enough voltage to run the fuel or ignition systems at that speed. the relay buzzing is also a sign of low voltage. check all the battery cables and the charging system. good luck, chuck.

Before you continue with all this revving in idle, make sure you dont have the ZFHP22 model transmission (identified by the P-R-N-D-3-2-1 gear-shift pattern with nooverdrive button). This tranny does not like to be revved in park or neutral.

You can destroy it very quickly by revving it in Park or Neutral. Ask me how I know :(

Noel