help we have a van that has no lights but when starting from dead stop it stumbles and back fires we did change engines this week and replacement engine does the same thing, first engine has 644000m iles on it second engine has 87000 miles this van is used for air freight thanks for all replies thundermug

 

You ight try a new fuel filter & a couple of cans of Sea-Foam carb cleaner.
HTH,
Bob

 

I m going to assume you use the same intake manifold for both motors?
So what codes did you get to come out of the ECM? I ll bet you have a code for signal range malfunction in the TPS. Big ol' flat spot between 0.5-4.5v. Where? Who knows? But check for codes and then post what they are...

No lights? Different issue.

 

van is fixed fuel pump was going out had good pressure but low volume also fuel line was crimped almost closed on top of tankline cost almost 200.00 from dealer but had to have it , thanks for your replies, thundermug